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Very recently, the controlled release of dopamine (DA), a neurotransmitter whose deficiency is associated with Parkinson's disease, has been postulated as a good alternative to the oral administration of levodopa (L-Dopa), a dopamine precursor, to combat the effects of said disease. However, this is still a very little explored field and there are very few carriers that are capable of releasing DA, a small and water-soluble molecule, in an efficient and controlled manner. In this work, we report a carrier based on a conductive hydrogel capable of loading DA and releasing it progressively and efficiently (100 % release) in a period of five days by applying small electrical stimuli (–0.4 V) daily for a short time (1 min). The hydrogel (CMC/PEDOT), which is electrically active, has been prepared from sodium carboxymethylcellulose and poly(3,4-ethylenedioxythiophene) microparticles, using citric acid as a cross-linking agent. Furthermore, the results have shown that when relatively hydrophobic small molecules, such as chloramphenicol, are loaded, the electrostimulated release is significantly less efficient, demonstrating the usefulness of CMC/PEDOT as a carrier for neurotransmitters., Postprint (author's final draft)

Polypropylene (PP), thermoplastic polyurethane (TPU), polyethylene terephthalate glycol (PETG) and polylactic acid (PLA) 3D printed specimens, which are intrinsically non-electroresponsive materials, have been converted into electroresponsive electrodes applying a low-pressure oxygen plasma treatment. After complete chemical, morphological and electrochemical characterization, plasma treated samples have been applied as integrated electrochemical sensors for detecting dopamine and serotonin by cyclic voltammetry and chronoamperometry. Results show differences in the sensing behavior, which have been explained on the basis of the chemical structure of the pristine materials. While plasma treated PLA exhibits the highest performance as electrochemical sensor in terms of sensitivity (lowest limits of detection and quantification) and selectivity (against uric acid and ascorbic acid as interfering substances), plasma treated PP displays the poorest behavior due to its low polarity compared to PLA 3D-printed electrodes. Instead, plasma treated TPU and PETG shows a very good response, much closer to PLA, as sensitive electrodes towards neurotransmitter molecules (dopamine and serotonin). Overall, results open a new door for the fabrication of electrochemical conductive sensors using intrinsically insulating materials, without the need of chemical functionalization processes., Postprint (author's final draft)

Starting from in-house synthesized allylic monomers containing dynamic disulfide (S–S) bonds, a set of vitrimeric thiol-ene elastomers were prepared and characterized with respect to their viscoelastic and tensile properties. A mixture of a disulfide-containing diallyl monomer and disulfide-free diallyl, namely diallyl phthalate, was combined stoichiometrically with a thiol crosslinker, trimethylolpropane tris (3-mercaptopropionate), to obtain soft thiol-ene thermosets with varying degrees of dynamic bond content. The materials were able to relax strain induced stress completely and rapidly at moderately high temperatures when the disulfide content was above a certain threshold, which was accurately predicted by a statistically-based network (de)crosslinking model. Relaxation of materials with disulfide content below this threshold required the activation of an additional transesterification bond exchange process by increasing the temperature. Recycling of the materials could be achieved by hot-press molding at convenient temperatures. Especially in low-disulfide containing materials, changes were observed in the material structure and properties with increasing number of reprocessing cycles. However, a significant reduction in ambient temperature creep was observed upon reducing the disulfide content. The disulfide content can be easily optimized to yield minimal loss of mechanical property and minimal creep. This work opens up new avenues for the cost-effective development of vitrimeric elastomers with minimal ambient temperature creep., The authors acknowledge the funds provided by the Spanish Ministry of Science and Innovation (MCNI/AEI) through R&D project PID2020- 115102RB-C22, and also by Generalitat de Catalunya (2021-SGR- 00154). O. Konuray and X. Fernández-Francos acknowledge the Serra- Húnter programme (Generalitat de Catalunya)., Peer Reviewed, Postprint (published version)

Aliphatic polyamides (nylons) show a remarkable variability in terms of crystallographic structures, polymorphic transitions and crystal morphology despite all polymers of this family have a simple constitution that is based on amide groups and polymethylene segments. Nylons derived from diamines and dicarboxylic acids having different parity (e.g., even or odd) have peculiar characteristics due to the difficulty of establishing an optimal hydrogen-bonding geometry when molecular chains adopt a typical all trans conformation. In this work, two isomeric odd-even (nylon 7,10) and even-odd (nylon 10,7) polyamides with the same methylene/amide ratio have been studied. Specifically, crystallization kinetics have been evaluated from calorimetric data, while thermal degradation mechanisms from thermogravimetric analysis. Classical methods (e.g., Avrami) together with isoconversional analyses have been considered for crystallization studies, being found significant differences between both nylons in terms of nucleation and activation energies. The isoconversional analyses of the non-isothermal crystallization allowed to determine the temperature dependence of both the crystal growth and the overall crystallization rate that points out the slower crystallization process of nylon 10,7. Isoconversional methods (integral and differential) were applied to evaluate thermal degradation. The mechanism was similar for both nylons (e.g., A3/2 and A1.8 for nylons 7,10 and 10,7, respectively), although a remarkable difference was determined for the corresponding activation energies (175 and 210 kJ/mol for nylons 7,10 and 10,7, respectively)., This research was funded by the Spanish Ministry of Science and Innovation through PID2022-140302OB-I00 and by the Generalitat de Catalunya under the project 2021-SGR-01042. Matteo Arioli is grateful for the support received from the Spanish Ministry of Science and Innovation, with the scholarship “Ayudas para contratos predoctorales para la formación de doctors/as 2019”., Peer Reviewed, Postprint (published version)

Catheter-associated urinary tract infections are the most common hospital-acquired infections and cause patient discomfort, increased morbidity, and prolonged stays, altogether posing a huge burden on healthcare services. Colonization occurs upon insertion, or later by ascending microbes from the rich periurethral flora, and is therefore virtually unavoidable by medical procedures. Importantly, the dwell time is a significant risk factor for bacteriuria because it gives biofilms time to develop and mature. This is why we engineer antibacterial and antibiofilm coating through ultrasound- and nanoparticle-assisted self-assembly on silicone surfaces and validate it thoroughly in vitro and in vivo. To this end, we combine bimetallic silver/gold nanoparticles, which exercise both biocidal and structural roles, with dopamine-modified gelatin in a facile and substrate-independent sonochemical coating process. The latter mussel-inspired bioadhesive potentiates the activity and durability of the coating while attenuating the intrinsic toxicity of silver. As a result, our approach effectively reduces biofilm formation in a hydrodynamic model of the human bladder and prevents bacteriuria in catheterized rabbits during a week of placement, outperforming conventional silicone catheters. These results substantiate the practical use of nanoparticle–biopolymer composites in combination with ultrasound for the antimicrobial functionalization of indwelling medical devices., Peer Reviewed, Postprint (published version)

Applications of sodium alginate (Alg) and polyacrylic acid (PAA) hydrogels in biomedicine are well-known. These are predefined by the strength and weakness of their properties, which in turn depend on the chemical structure and the architecture of their crosslinks. In this work, Alg biopolymer has been grafted to synthetic PAA that has been chemically crosslinked using N,N'-methylene-bisacrylamide (MBA) to produce a pH responsive hydrogel with adhesive property. The double crosslinking network, which combines MBA-mediated covalent crosslinks and ionic crosslinks in Alg domains, results in an elastic modulus that resembles that of highly anisotropic and viscoelastic human skin. After addressing the influence of the dual network onto the Alg-g-PAA hydrogel properties, a prospection of its potential as an adhesive has been made considering different surfaces (rubber, paper steel, porcine skin, etc). The bonding energy onto porcine skin, 32.6 ± 4.6 J/m2, revealed that the Alg-g-PAA hydrogel can be proposed in the biomedical field as tissue adhesive for wound healing applications. Finally, the hydrogel has been semi-interpenetrated with poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-MeOH) chains through a chemical oxidative polymerization process. The resulting hydrogel, Alg-g-PAA/PEDOT-MeOH, which is even more porous than Alg-g-PAA, in addition to being electro-responsive, maintains adhesive properties., Peer Reviewed, Postprint (published version)

Conductive hydrogels are becoming one of the most important milestones for the development of new scaffolds, biosensors, supercapacitors, and green electronics within the field of biomedicine. In this work, we study the effect of different types of electroactive additives such as poly(3,4-ethylenedioxythiophene), tannic acid, and carbon quantum dots (CQDs), to form different poly(vinyl alcohol) (PVA)-based hydrogels with enhanced electrochemical properties. Different physicochemical tests are carried out to characterize the different PVA-based hybrid hydrogels and the rates of their degradation and loss of electroactivity throughout an eight-week biodegradation process. This work shows the individual and synergistic effects of the additives on various mechanical properties, including storage modulus and swelling ratio, and electrochemical properties of the PVA hydrogel. The additives have proven to enhance the electroactivity of the PVA-based hydrogels but as well their degradation. Finally, the use of the new hydrogel as a pressure sensor is also investigated. The study provides an insight on the potential use of CQDs, in synergy with other electroactivity enhancers, in the fabrication of novel hybrid conducting hydrogels in green electronics., Peer Reviewed, Postprint (published version)

The utilization of biomimetic membranes supported by advanced self-assembled monolayers is gaining attraction as a promising sensing tool. Biomimetic membranes offer exceptional biocompatibility and adsorption capacity upon degradation, transcending their role as mere research instruments to open new avenues in biosensing. This study focused on anchoring a sparsely tethered bilayer lipid membrane onto a self-assembled monolayer composed of a biodegradable polymer, functionalized with poly(ethylene glycol)-cholesterol moieties, for lipid membrane integration. Real-time monitoring via quartz crystal microbalance, coupled with characterization using surface-enhanced infrared absorption spectroscopy and electrochemical impedance spectroscopy, provided comprehensive insights into each manufacturing phase. The resulting lipid layer, along with transmembrane pores formed by gramicidin A, exhibited robust stability. Electrochemical impedance spectroscopy analysis confirmed membrane integrity, successful pore formation, and consistent channel density. Notably, gramicidin A demonstrated sustained functionality as an ion channel upon reconstitution, with its functionality being effectively blocked and inhibited in the presence of calcium ions. These findings mark significant strides in developing intricate biodegradable nanomaterials with promising applications in biomedicine., Peer Reviewed, Postprint (published version)

Linear polyamides, known as nylons, are a class of synthetic polymers with a wide range of applications due to their outstanding properties, such as chemical and thermal resistance or mechanical strength. These polymers have been used in various fields: from common and domestic applications, such as socks and fishing nets, to industrial gears or water purification membranes. By their durability, flexibility and wear resistance, nylons are now being used in addictive manufacturing technology as a good material choice to produce sophisticated devices with precise and complex geometric shapes. Furthermore, the emergence of triboelectric nanogenerators and the development of biomaterials have highlighted the versatility and utility of these materials. Due to their ability to enhance triboelectric performance and the range of applications, nylons show a potential use as tribo-positive materials. Because of the easy control of their shape, they can be subsequently integrated into nanogenerators. The use of nylons has also extended into the field of biomaterials, where their biocompatibility, mechanical strength and versatility have paved the way for groundbreaking advances in medical devices as dental implants, catheters and non-absorbable surgical sutures. By means of 3D bioprinting, nylons have been used to develop scaffolds, joint implants and drug carriers with tailored properties for various biomedical applications. The present paper aims to collect evidence of these recently specific applications of nylons by reviewing the literature produced in recent decades, with a special focus on the newer technologies in the field of energy harvesting and biomedicine., Peer Reviewed, Postprint (published version)

Bacterial contamination is a hazard in many industries, including food, pharmaceuticals, and healthcare. The availability of a rapid and simple method for detecting this type of contamination in sterile areas enables immediate intervention to avoid or reduce detrimental effects. Among these methods, colorimetric indicators are becoming increasingly popular due to their affordability, ease of use, and quick visual interpretation of the signal. In this article, a bacterial contamination indicator system was designed by incorporating MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) into an electrospun PADAS matrix, which is a biodegradable poly(ester amide) synthesized from L-alanine, 1,12-dodecanediol, and sebacic acid. Uniaxial stress testing, thermogravimetric analysis and scanning electron microscopy were used to examine the mechanical properties, thermal stability, and morphology of the mats, respectively. The capacity for bacterial detection was not only analyzed with agar and broth assays but also by replicating important environmental conditions. Among the MTT concentrations tested in this study (0.2%, 2%, and 5%), it was found that only with a 2% MTT content the designed system produced a color response visible to the naked eye with optimal intensity, a sensitivity limit of 104 CFU/mL, and 86% cell viability, which showed the great potential for its use to detect bacterial contamination. In summary, by means of the process described in this work, it was possible to obtain a simple, low-cost and fast-response bacterial contamination indicator that can be used in mask filters, air filters, or protective clothing., This research was funded by the Spanish Ministry of Science, Innovation and Universities through PID2022-140302OB-I00 and by the Generalitat de Catalunya under the project 2021-SGR-01042., Peer Reviewed, Postprint (published version)

In accordance with the Circular Economy Package of the European directive, the Spanish government compels manufacturers of plastic bags to include into their products a minimum of 70% of polyethylene (PE) waste. Following this mandate can be challenging and requires a deep knowledge of the alterations produced by the recycling in the main components of a plastic bag film: lineal low-density polyethylene (LLDPE), the LLDPE recycled post-industry, generated as waste from an industrial process (rLLDPE) and the PE recycled from post-consumer use (rPE), that has been picked up, cleaned, and reprocessed. This study provides insight in the macro and microstructural changes produced by several cycles of recycling in these materials. Specimens in the form of film for supermarket bags formed with these polymers have been subjected to several recycling sequences. The process closely mimics industrial processes. Four cycles have been applied to the samples. The evolution of mechanical properties, including tensile strength, elongation at break, and tear and impact tests, shows an obvious decrease due to degradation that is not an impediment for practical use after the four cycles of recycling according to the main specifications defined by the producer. Colorimetric measurements reveal no significant variations in the color of the films. The results of the FTIR and TGA analysis show degradation phenomena and changes in crystallinity in branching and the apparition of crosslinking that are in consonance with the mechanical data. There is also a difference between both types of recycled PE. In general, rLLDPE is more affected by the recycling than rPE. According to our findings, the limiting property would be the tearing. By comparing these values with bags available in the market, manufactured from 70–80% recycled material, we can infer that while two reprocessing cycles can lead to good results, a maximum of four cycles of recycling is advisable, The manuscript is part of grant PID2021-126165OB-I00 founded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe by the European Union. ​We are significantly grateful for the work carried out by S. Fernández Ayala and E. Molina Salazar in the laboratories of the company Sphere Spain, Postprint (published version)

This work presents the design and construction of an automated industrial injection moulding apparatus that can be used with a typical multi-user beamline such as the NCD-SWEET small-angle X-ray scattering at the ALBA Synchrotron Light Source. This apparatus is focused on developing an understanding of how the mould temperature and the injection temperature and pressure affect both the orientation and morphology of the semi-crystalline polymer used to fabricate the injected parts. The system design follows current industrial practice and enables the collection of time-resolved X-ray scattering data at several points within the mould cavity, so we can understand the 4D morphology. In this work we show the effectiveness of the equipment using some results from the injection moulding of a random copolymer of polypropylene and that it can be used with a more demanding material such as polyhydroxybutyrate. This can be seen as the first step toward a multiscale digital twin for injection moulding., Open access funding provided by FCT|FCCN (b-on). This work is supported by the Fundação para a Ciência e Tecnologia (FCT) through the Project references: MIT-EXPL/TDI/0044/2021, https://doi.org/10.54499/UIDB/04044/2023; PAMI-ROTEIRO/0328/2013 (Nº022158), Add.Additive-POCI-01–0247-FEDER-024533, Tailored Cooling (POCI-01–0145-FEDER- 03243), PRR 2375 Bioshoes4All and PRR INOVAM C644865234-00000004. Matteo Arioli is grateful for the support received from the Ministerio de Ciencia, Innovación y Universidades of Spain, with the mobility program of the grant “Ayudas para contratos predoctorales para la formación de doctors as 2019.”, Peer Reviewed, Postprint (published version)

Polymeric membranes exhibit unique and modulate transport properties when they are properly functionalised, which make them ideal for ions transport, molecules separation and molecules interactions. The present work proposes the design and fabrication of nanostructured membranes, composed by biodegradable poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG), incorporating a lipophilic molecule (cholesterol) covalently bonded, were especially designed to provide even more application opportunities in sensors field. Electrochemical studies, by means of electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and square wave voltammetry (SWV), revealed important differences regarding the functionalised and non-functionalised PLA systems. PEG-cholesterol building block units showed a clear affinity with ascorbic acid (vitamin C) and Trolox® (a water-soluble analogue of vitamin E), both hydrophilic in nature, with a limit of detection capacity of 8.12 µM for AA and 3.53 µM for AA and Trolox, respectively, in aqueous salt solution. The bioinspired polymer may be used to incorporate antioxidant property that allow the design of anti-stress biosensors, electrodes for the detection of vitamin C or vitamin E in biomedical nutrition programs, among other applications., The authors thank the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement BioInspireSensing No 955643 for supporting this work. Authors also acknowledge the Agència de Gestió d'Ajuts Universitaris i de Recerca, AGAUR (Grant number: 2021 SGR 00387), by Generalitat de Catalunya (Spain), for the financial support of this research., Peer Reviewed, Postprint (published version)

To improve the features of alginate-based hydrogels in physiological conditions, Ca2+-crosslinked semi-interpenetrated hydrogels formed by poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid and alginate (PEDOT/Alg) were subjected to a treatment with glyoxal to form a dual ionic/covalent network. The covalent network density was systematically varied by considering different glyoxalization times (tG). The content of Ca2+ was significantly higher for the untreated hydrogel than for the glyoxalized ones, while the properties of the hydrogels were found to largely depend on tG. The porosity and swelling capacity decreased with increasing tG, while the stiffness and electrical conductance retention capacity increased with tG. The potentiodynamic response of the hydrogels notably depended on the amount of conformational restraints introduced by the glyoxal, which is a very short crosslinker. Thus, the re-accommodation of the polymer chains during the cyclic potential scans became more difficult with increasing number of covalent crosslinks. This information was used to improve the performance of untreated PEDOT/Alg as electrochemical sensor of hydrogen peroxide by simply applying a tG of 5 min. Overall, the control of the properties of glyoxalized hydrogels through tG is very advantageous and can be used as an on-demand strategy to improve the performance of such materials depending on the application., This publication is part of the I+D+i project PID2021-125767OB-I00 and PLEC2022-009279 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, by the European Union. Authors are thankful to the Agència de Gestió d'Ajuts Universitaris i de Recerca (2021 SGR 00387 and 2021 SGR 01368) for financial support. JM thanks FCT financial support under the project UIDB/50008/2020. M.M.P.-M. thanks the Ministerio de Ciencia, Innovación y Universidades for the Junior Beatriz Galindo Award (BG20/00216). J.G.-T. acknowledges the Serra Hunter program of the Generalitat de Catalunya. Support for the research of C.A. was also received through the prize “ICREA Academia” for excellence in research funded by the Generalitat de Catalunya. S.C. thanks the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR; Generalitat de Catalunya) for a FI Fellowship., Peer Reviewed, Postprint (published version)

Surgical sutures are long-established medical devices that play an important role closing and healing damaged tissues and organs postoperatively. However, current commercial sutures are not able to detect infections at the wound site, which are quite frequent after surgery. In this work, we present mechanically stable smart sutures for the real-time monitoring of bacterial growth and biofilm formation. For this purpose, a conducting polymer named poly(3,4-ethylenedioxythiophene) (PEDOT), which is able to detect bacteria metabolites, was implemented as a coating onto commercial biostable sutures. A protecting hydrogel layer with adhesive properties, which was made of polydopamine-polyacrylamide (PDA-PAM), was used to prevent the detachment of the sensing coating of PEDOT upon looping and knotting the suture. The protective hydrogel preserved not only the knot mechanical properties of the suture but also the electrochemical response of the PEDOT-coating and, therefore, its ability to detect NADH from bacteria respiration. Ex-vivo assays using sutured swine intestine samples demonstrated that the suture with the PDA-PAM hydrogel layer detects the growth of bacteria in real tissues. As a proof of concept, sutures coated with PEDOT and protected with PDA-PAM were used to inhibit the local growth of bacteria in sutured intestines by applying controlled electrostimuli. Results evidenced that smart electro-responsive sutures can be used as multi-task devices focused on fighting bacterial infections, meaning not only monitoring but also hampering bacteria growth., Postprint (author's final draft)

The development of smart biomedical devices as efficient tools in early diagnosis and therapy monitoring has recently witnessed unprecedented growth, becoming an emerging field in biomedical engineering. Sponges for endoluminal vacuum therapy, which are intended for transmitting negative pressure as trigger for tissue regeneration and for draining infections in anastomotic leakages, are massively used implants with very complex geometry and high risk of infection. In this work, commercial polyurethane (PU) sponges have been converted into smart biomedical devices by incorporating an electrochemical sensor to monitor the growth of bacteria. Such innovative approach, which allows to track the tissue healing process avoiding further infection development, has been performed applying a three-step process: 1) activation of PU using low pressure oxygen plasma; 2) incorporation of conducting polymer (CP) nanoparticles (NPs) at the surface of the activated PU by chemical oxidative polymerization; and 3) formation of a homogeneous electroactive coating using the CP NPs obtained in 2), as growth nuclei in an electrochemical polymerization. The functionalized PU sponge is able to monitor the bacteria growth in the surrounding media by detecting the concentration of nicotinamide adenine dinucleotide (NADH) from respiration reactions in the cytosol (i.e. bacteria do not have mitochondria). Conversely, respiration in normal eukaryotic cells takes place in the mitochondria, whose double membrane is not permeable to NADH. The sensing performance of the CP-coated PU sponges (limit of detection: 0.06¿mM; sensitivity: 1.21¿mA/cm2) has been determined in the lab using NADH solutions, while a proof of concept have been conducted using Escherichia coli bacteria cultures., Postprint (author's final draft)

This work proposes a microfibers-hydrogel assembled composite as delivery vehicle able to combine into a single system both burst and prolonged release of lactate. The prolonged release of lactate has been achieved by electrospinning a mixture of polylactic acid and proteinase K (26.0 mg of proteinase K and 0.99 g of PLA dissolved in 6 mL of 2:1 chloroform:acetone in the optimal case), which is a protease that catalyzes the degradation of polylactic acid into lactate. The degradation of microfibers into lactate reflects that proteinase K preserves its enzymatic activity even after the electrospinning process because of the mild operational conditions used. Besides, burst release is obtained from the lactate-loaded alginate hydrogel. The successful assembly between the lactate-loaded hydrogel and the polylactic acid/proteinase K fibers has been favored by applying a low-pressure (0.3 mbar at 300 W) oxygen plasma treatment, which transforms hydrophobic fibers into hydrophilic while the enzymatic activity is still maintained. The composite displays both fast (< 24 h) and sustained (> 10 days) lactate release, and allows the modulation of the release by adjusting either the amount of loaded lactate or the amount of active enzyme., This publication is part of the I+D+i project PID2021-125767OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, by the European Union. L.P.M. acknowledges financial support to Consejo Nacional de Investigaciones Científicas y Tecnicas (CONICET) for her research stay in UPC. Authors are thanked to the Agència de Gestió d'Ajuts Universitaris i de Recerca (2021 SGR 00387) for financial support. J.G.-T. acknowledges the Serra Hunter program of the Generalitat de Catalunya., Peer Reviewed, Postprint (author's final draft)

The environmental degradation of the films used in packaging is a key factor in their commercial use. Industrial and academic research is aimed at obtaining materials that have degradation features that ensure their eco-sustainability but, at the same time, preserve their use properties during storage and distribution periods. This study analyzes the degradability behavior over time of commercial packaging that meets the requirements of the UNE 13432 standard and the prEN 17427 (2020) home composting certification requirements under standard storage conditions. The study attempts to provide insight into the durability of the films under standard storage conditions, verifying that this type of packaging has a useful life of more than 12 months and that after this storage period it still retains the usability properties for which it was conceived. The analyzed sample has been manufactured using a three-layer technology under some commercial formulations based on PBAT + STARCH + PLA and has been analyzed monthly for 12 consecutive months. The macroscopic monitoring of the degradation of the sample has been carried out through the evolution of the mechanical properties and the quantification of the color changes (very important in films) via colorimetry. The nature of the observed variations has been justified at the microstructural level from the data obtained in calorimetric analysis (DSC) and from the characterization using FTIR. The results indicate a loss of properties in the tensile, elongation and impact tests and a behavior of stability or improvement in the tear properties of the film. Analyzing the microstructural changes, it is observed that the degradation of a hydrolytic and thermo-oxidative type occurs in the amorphous part of the film. The conclusion of this study is that the proposed packaging, focused on domestic composting and stored under standard conditions, has a useful life of more than 12 months. This period should be sufficient to cover the stage, Peer Reviewed, Postprint (published version)

Our current industrial ammonia cycle is far from being sustainable – while intense energy is required to produce ammonia – almost half of it ends up in wastewater treatment plants (WWTPs) where is finally transformed and lost. This work shows the application of flat sheet membrane distillation (MD) commercial modules for the ammonia recovery from WWTPs. First, optimized operating conditions – in terms of ammonia flux, specific thermal energy (STEC) and chemical demand – were investigated in the laboratory with a 2.3 m2 MD module. Second, optimized conditions were demonstrated in a pilot installation on site operating a 14.5 m2 MD module continuously (24/7) for three months. Results showed that MD is a robust, low-maintenance technology that can be operated at low temperature and corresponding STEC (i.e. 38 °C and 13.6 kWhth per kg1 NH3, respectively) and low pH (i.e. 8.7) for the recovery of 90% of the water-bound ammonia as an ammonium sulphate (AS) solution. The AS product reached a concentration of 5 g l-1 N–NH4, lower than conventional fertilizers, however given its high quality and volume reduction factor, it constitutes a potential fertilizer solution for local needs. The maximum AS permeate concentration was limited by the increasing water vapour flux due to a higher osmotic distillation effect and a minor ammonia flux decrease with increasing permeate concentration. Further research will focus on optimizing the module configuration to minimize water flux and overall system operation for increased heat recovery and open-loop operation., Peer Reviewed, Postprint (published version)

Lately, there has been an increasing demand for materials that could improve tissue regenerative therapies and provide antimicrobial effects. Similarly, there is a growing need to develop or modify biomaterials for the diagnosis and treatment of different pathologies. In this scenario, hydroxyapatite (HAp) appears as a bioceramic with extended functionalities. Nevertheless, there are certain disadvantages related to the mechanical properties and lack of antimicrobial capacity. To circumvent them, the doping of HAp with a variety of cationic ions is emerging as a good alterative due to the different biological roles of each ion. Among many elements, lanthanides are understudied despite their great potential in the biomedical field. For this reason, the present review focuses on the biological benefits of lanthanides and how their incorporation into HAp can alter its morphology and physical properties. A comprehensive section of the applications of lanthanides-substituted HAp nanoparticles (HAp NPs) is presented to unveil the potential biomedical uses of these systems. Finally, the need to study the tolerable and non-toxic percentages of substitution with these elements is highlighted., Peer Reviewed, Postprint (published version)

Surface treatments for textile substrates have received significant attention from researchers around the world. Ozone and plasma treatments trigger a series of surface alterations in textile substrates that can improve the anchoring of other molecules or particles on these substrates. This work aims to evaluate the effect of ozone and plasma treatments on the impregnation of polymeric microcapsules containing lavender oil in polyester fabrics (PES). Microcapsules with walls of chitosan and gum arabic were prepared by complex coacervation and impregnated in PES, plasma-treated PES, and ozone-treated PES by padding. The microcapsules were characterized for their size and morphology and the surface-treated PES was evaluated by FTIR, TGA, SEM, and lavender release. The microcapsules were spherical in shape, with smooth surfaces. The FTIR analyses of the textile substrates with microcapsules showed bands referring to the polymers of the microcapsules, but not to the lavender; this was most likely because the smooth surface of the outer wall did not retain the lavender. The mass loss and the degradation temperatures measured by TGA were similar for all the ozone-treated and plasma-treated polyester samples. In the SEM images, spherical microcapsules and the impregnation of the microcapsules of larger sizes were perceived. Through the lavender release, it was observed that the plasma and ozone treatments interfered both with the amount of lavender delivered and with the control of the delivery., Peer Reviewed, Postprint (author's final draft)

The industrial interest in the patterning of polymeric surfaces at the micro/nanoscale to include new functionalities has considerably increased during the last years. Hierarchical organization of micro/nanometric surface textures yields enhanced functional properties such as hydrophobicity, hydrophilicity, antibacterial activity, and optical or chromatic effects to cite some. While high accuracy methods to pattern hierarchical surfaces at the nanoscale have been developed, only some of them have been applied for high volume manufacturing with limited success, mainly because they rely on the use of expensive machinery and moulds or complicated inserts. Therefore, a method using low cost recyclable tooling and process conditions applicable to high-volume manufacturing is currently missing. In this work, a scalable and low-cost method to replicate hierarchical micro/nanostructured surfaces on plastic films is presented, which can be latter used as inlays for injection moulded parts with standard processing conditions. This method is used to demonstrate the feasibility of replicating three level hierarchical micro/nano textured surfaces using recyclable bio-based polymers (of high relevancy in the current plastic pollution context) achieving replication ratios above 90%, comparing the replication results with those obtained in polypropylene. The presence of the micro/nanotextures substantially increases the contact angle of all the polymers tested, yielding values higher than 90° in all the cases. Also, various mechanical properties of the replicated parts for all the polymers injected are characterized one and thirty days after the samples were manufactured, showing fairly constant values. This highlights the validity of the replicated surfaces, regardless of the biopolymers special crystallization characteristics., Peer Reviewed, Postprint (published version)

Multiresponsive hydrogels, which are smart soft materials that respond to more than one external stimulus, have emerged as powerful tools for biomedical applications, such as drug delivery. Within this context and with the aim of eliminating the systematic administration of antibiotics, special attention is being paid to the development of systems for controlled delivery of antibiotic for topical treatment of bacterial infections. In this work, an electro-chemo responsive hydrogel able to release chloramphenicol (CAM), a broad spectrum antibiotic also used for anticancer therapy, is proposed. This has been prepared by grafting poly(acrylic acid) (PAA) to sodium alginate (Alg) and in situ encapsulation of poly(3,4-ethylenedioxythiophene) nanoparticles loaded with CAM (PEDOT/CAM NPs), which were obtained by emulsion polymerization. Although the response to electrical stimuli of PEDOT was the main control for the release of CAM from PEDOT/CAM NPs, the release by passive diffusion had a relatively important contribution. Conversely, the passive release of antibiotic from the whole engineered hydrogel system, Alg-g-PAA/PEDOT/CAM, was negligible, whereas significant release was achieved under electrostimulation in an acid environment. Bacterial tests and assays with cancer cells demonstrated that the biological activity of CAM remained after release by electrical stimulation. Notably, the successful dual-response of the developed hydrogel to electrical stimuli and pH changes evidence the great prospect of this smart material in the biomedical field, as a tool to fight against bacterial infections and to provide local cancer treatment., Peer Reviewed, Postprint (author's final draft)

The development of experimental procedures to transform conventional materials into new materials with unique properties has become a necessity in many fields, as for example catalysis, electronics, electrochemistry and biomedicine, among others. In recent years, the thermal stimulated polarization (TSP) treatment, which consists of applying a constant voltage at a high temperature, has been applied to hydroxyapatite, Ca5(PO4)3OH (HAp), leading to permanently polarized HAp (p-HAp). The enhanced electrical properties of p-HAp, which are the consequence of the controlled generation of vacancies, the specific orientation of the remaining OH– groups and the surface charge accumulation have been used for the catalytic fixation of CO2, CH4 and/or N2 under very mild conditions (<120 °C) and with accurate selectivity toward different reaction products (up to 95%). In this Perspective, we stablish the fundamentals of permanently polarized materials, providing the generalized concepts of the permanent polarized state and some representative examples of applying the TSP approach to a wide variety of materials. More specifically, we provide empirical evidence of the polarized state after applying the TSP treatment to quartz nanopowder, binary metal oxides (TiO2 and ZrO2) and different synthetic polymers, confirming the obtaining of enhanced electrical properties and the associated structural changes. Finally, the implications, challenges and perspectives of the polarized state are discussed considering different fields, such as catalysis, biomedicine, optics and electronics, sensors and energy storage devices., Peer Reviewed, Postprint (author's final draft)

Biosensors are increasingly taking a more active role in health science. The current needs for the constant monitoring of biomedical signals, as well as the growing spending on public health, make it necessary to search for materials with a combination of properties such as biocompatibility, electroactivity, resorption, and high selectivity to certain bioanalytes. Conducting polymer hydrogels seem to be a very promising materials, since they present many of the necessary properties to be used as biosensors. Furthermore, their properties can be shaped and enhanced by designing conductive polymer hydrogel-based composites with more specific functionalities depending on the end application. This work will review the recent state of the art of different biological hydrogels for biosensor applications, discuss the properties of the different components alone and in combination, and reveal their high potential as candidate materials in the fabrication of all-organic diagnostic, wearable, and implantable sensor devices., Peer Reviewed, Postprint (published version)

Although the main function of skin is to act as a protective barrier against external factors, it is indeed an extremely vulnerable tissue. Skincare, regardless of the wound type, requires effective treatments to prevent bacterial infection and local inflammation. The complex biological roles displayed by hyaluronic acid (HA) during the wound healing process have made this multifaceted polysaccharide an alternative biomaterial to prepare wound dressings. Therefore, herein, we present the most advanced research undertaken to engineer conductive and interactive hydrogels based on HA as wound dressings that enhance skin tissue regeneration either through electrical stimulation (ES) or by displaying multifunctional performance. First, we briefly introduce to the reader the effect of ES on promoting wound healing and why HA has become a vogue as a wound healing agent. Then, a selection of systems, chosen according to their multifunctional relevance, is presented. Special care has been taken to highlight those recently reported works (mainly from the last 3 years) with enhanced scalability and biomimicry. By doing that, we have turned a critical eye on the field considering what major challenges must be overcome for these systems to have real commercial, clinical, or other translational impact., Peer Reviewed, Postprint (author's final draft)

Isotactic polypropylene (i-PP) nonabsorbable surgical meshes are modified by incorporating a conducting polymer (CP) layer to detect the adhesion and growth of bacteria by sensing the oxidation of nicotinamide adenine dinucleotide (NADH), a metabolite produced by the respiration reactions of such microorganisms, to NAD+. A three-step process is used for such incorporation: (1) treat pristine meshes with low-pressure O2 plasma; (2) functionalize the surface with CP nanoparticles; and (3) coat with a homogeneous layer of electropolymerized CP using the nanoparticles introduced in (2) as polymerization nuclei. The modified meshes are stable and easy to handle and also show good electrochemical response. The detection by cyclic voltammetry of NADH within the interval of concentrations reported for bacterial cultures is demonstrated for the two modified meshes. Furthermore, Staphylococcus aureus and both biofilm-positive (B+) and biofilm-negative (B-) Escherichia coli cultures are used to prove real-time monitoring of NADH coming from aerobic respiration reactions. The proposed strategy, which offers a simple and innovative process for incorporating a sensor for the electrochemical detection of bacteria metabolism to currently existing surgical meshes, holds considerable promise for the future development of a new generation of smart biomedical devices to fight against post-operative bacterial infections., Postprint (published version)

Bioresorbable nanomembranes (NMs) and nanoparticles (NPs) are powerful polymeric materials playing an important role in biomedicine, as they can effectively reduce infections and inflammatory clinical patient conditions due to their high biocompatibility, ability to physically interact with biomolecules, large surface area, and low toxicity. In this review, the most common bioabsorbable materials such as those belonging to natural polymers and proteins for the manufacture of NMs and NPs are reviewed. In addition to biocompatibility and bioresorption, current methodology on surface functionalization is also revisited and the most recent applications are highlighted. Considering the most recent use in the field of biosensors, tethered lipid bilayers, drug delivery, wound dressing, skin regeneration, targeted chemotherapy and imaging/diagnostics, functionalized NMs and NPs have become one of the main pillars of modern biomedical applications., This research was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement BioInspireSensing No 955643., Peer Reviewed, Postprint (published version)

We recently introduced the possibility of performing operando small-angle X-ray scattering measurements using a novel industrially relevant injection moulding system for plastics. We show that useful time-resolving measurements can be performed with a time-cycle of 1 s and highlight the possible steps to reduce this to 0.5 s. We show how we can use the transmission measurements to provide a time marker when plastic first enters the mould cavity in the region probed by the incident X-ray beam. We show the opportunities provided by this experimental stage mounted on the NCD-SWEET beamline at ALBA to probe the reproducibility of the injection moulding system on different scales. The design of the equipment allowed for the development of the structure and the morphology to be evaluated in different parts of mould cavity, and we evaluated any differences in a rectangular mould cavity. We identified future prospects for this equipment in terms of novel mould heating and cooling systems and the opportunities for quantitatively evaluating radical approaches to injection moulding technology., This work was financially supported by the Fundação para a Ciência e a Tecnologia FCT/MCTES (PIDDAC) through the following Projects: MIT-EXPL/TDI/0044/2021, UIDB/04044/2020; UIDP/04044/2020; Associate Laboratory ARISE LA/P/0112/2020; PAMI—ROTEIRO/0328/2013 (No. 022158); plus EcoPlast, Materiais compósitos eco-sustentáveis para substituição dos plásticos convencionais, ref POCI-01-0247-FEDER-069002; and INNOV-AM funded by National Agency of Innovation M.A. is grateful for the support received from the Ministerio de Ciencia, Innovación y Universidades of Spain, with the mobility program of the grant “Ayudas para contratos predoctorales para la formación de doctoresas 2019”., Peer Reviewed, Postprint (published version)

Trace metals are essential elements that play key roles in a number of biochemical processes governing human visual physiology in health and disease. Several trace metals, such as zinc, have been shown to play important roles in the visual phototransduction process. In spite of this, there has been little research conducted on the direct effect of trace metal elements on the visual photoreceptor rhodopsin. In the current study, we have determined the effect of several metal ions, such as iron, copper, chromium, manganese, and nickel, on the conformational stability of rhodopsin. To this aim, we analyzed, by means of UV-visible and fluorescence spectroscopic methods, the effects of these trace elements on the thermal stability of dark rhodopsin, the stability of its active Metarhodopsin II conformation, and its chromophore regeneration. Our results show that copper prevented rhodopsin regeneration and slowed down the retinal release process after illumination. In turn, Fe3+, but not Fe2+, increased the thermal stability of the dark inactive conformation of rhodopsin, whereas copper ions markedly decreased it. These findings stress the important role of trace metals in retinal physiology at the photoreceptor level and may be useful for the development of novel therapeutic strategies to treat retinal disease., This research was funded by grants from Ministry of Science and Innovation, Spain (PID2019-104817GB-I00), and from the Government of Catalonia to Research Consolidated Groups (2021 SGR 00342) to P.G. F.W. is the recipient of a predoctoral grant from the Secretariat for Universities and Research of the Ministry of Business and Knowledge of the Government of Catalonia and the European Social Fund (2021 FI_B 00228)., Peer Reviewed, Postprint (published version)

Medical gloves, along with masks and gowns, serve as the initial line of defense against potentially infectious microorganisms and hazardous substances in the health sector. During the COVID-19 pandemic, medical gloves played a significant role, as they were widely utilized throughout society in daily activities as a preventive measure. These products demonstrated their value as important personal protection equipment (PPE) and reaffirmed their relevance as infection prevention tools. This review describes the evolution of medical gloves since the discovery of vulcanization by Charles Goodyear in 1839, which fostered the development of this industry. Regarding the current market, a comparison of the main properties, benefits, and drawbacks of the most widespread types of sanitary gloves is presented. The most common gloves are produced from natural rubber (NR), polyisoprene (IR), acrylonitrile butadiene rubber (NBR), polychloroprene (CR), polyethylene (PE), and poly(vinyl chloride) (PVC). Furthermore, the environmental impacts of the conventional natural rubber glove manufacturing process and mitigation strategies, such as bioremediation and rubber recycling, are addressed. In order to create new medical gloves with improved properties, several biopolymers (e.g., poly(vinyl alcohol) and starch) and additives such as biodegradable fillers (e.g., cellulose and chitin), reinforcing fillers (e.g., silica and cellulose nanocrystals), and antimicrobial agents (e.g., biguanides and quaternary ammonium salts) have been evaluated. This paper covers these performance-enhancing materials and describes different innovative prototypes of gloves and coatings designed with them., Peer Reviewed, Objectius de Desenvolupament Sostenible::3 - Salut i Benestar, Postprint (published version)

The incorporation of exogenous lactate into cardiac tissues is a regenerative strategy that is rapidly gaining attention. In this work, two polymeric platforms were designed to achieve a sustained release of lactate, combining immediate and prolonged release profiles. Both platforms contained electrospun poly(lactic acid) (PLA) fibers and an alginate (Alg) hydrogel. In the first platform, named L/K(x)/Alg-PLA, lactate and proteinase K (x mg of enzyme per 1 g of PLA) were directly loaded into the Alg hydrogel, into which PLA fibers were assembled. In the second platform, L/Alg-K(x)/PLA, fibers were produced by electrospinning a proteinase K:PLA solution and, subsequently, assembled within the lactate-loaded hydrogel. After characterizing the chemical, morphological, and mechanical properties of the systems, as well as their cytotoxicity, the release profiles of the two platforms were determined considering different amounts of proteinase K (x = 5.2, 26, and 52 mg of proteinase K per 1 g of PLA), which is known to exhibit a broad cleavage activity. The profiles obtained using L/Alg-K(x)/PLA platforms with x = 26 and 52 were the closest to the criteria that must be met for cardiac tissue regeneration. Finally, the amount of lactate directly loaded in the Alg hydrogel for immediate release and the amount of protein in the electrospinning solution were adapted to achieve a constant lactate release of around 6 mM per day over 1 or 2 weeks. In the optimized bioplatform, in which 6 mM lactate was loaded in the hydrogel, the amount of fibers was increased by a factor of ×3, the amount of enzyme was adjusted to 40 mg per 1 g of PLA, and a daily lactate release of 5.9 ± 2.7 mM over a period of 11 days was achieved. Accordingly, the engineered device fully satisfied the characteristics and requirements for heart tissue regeneration., Peer Reviewed, Postprint (author's final draft)

In this study entitled “Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering”, we describe the development of novel hydroxyapatite (HAp)-filled osteoinductive piezoelectric poly(vinylidene fluoride-cotetrafluoroethylene) (PVDF-TrFE) electrospun nanofibers as a potential strategy for supporting bone repair in delayed-union and non-union osteoporotic-related fractures, for which current clinical techniques have proven to be largely inadequate and scaffold-based tissue engineering approaches hold significant promise. While the piezoelectric properties of native bone tissue have been extensively discussed in the literature, including their key role in preserving tissue homeostasis and promoting tissue repair, they have been widely neglected in the design of scaffolds for bone tissue engineering (BTE) applications. Piezoelectric scaffolds can be used not only for mimicking the native piezoelectric features of bone but also to provide a platform for applying electrical or mechanical stimuli to damaged tissue, contributing to an accelerated regeneration process. The nanofibrous scaffolds generated in this study were capable of replicating the main electrical, structural and compositional properties of bone extracellular matrix (ECM). To the best of our knowledge, this was the first time that the combination of HAp with the piezoelectric polymer PVDF-TrFE was found to induce key shifts in the chemical structure of the polymer and promote ß phase nucleation, not only enhancing the piezoelectric features of the constructs but also improving their surface properties, including their ability to support mineralization in vitro. The HAp nanoparticles also provided meaningful bone-like biological cues (osteoinduction), enhancing the osteogenic differentiation of seeded human mesenchymal stem/stromal cells (hMSCs), which was confirmed by an increased ALP activity, cellderived calcium deposition and expression of important osteogenic gene mar, Peer Reviewed, Postprint (published version)

Micromechanical cantilever sensors are attracting a lot of attention because of the need for characterizing, detecting, and monitoring chemical and physical properties, as well as compounds at the nanoscale. The fields of application of micro-cantilever sensors span from biological and point-of-care, to military or industrial sectors. The purpose of this work focuses on thermal and mechanical characterization, environmental monitoring, and chemical detection, in order to provide a technical review of the most recent technical advances and applications, as well as the future prospective of micro-cantilever sensor research., Peer Reviewed, Postprint (published version)

The use of solar energy (natural) and synthetic solar absorber hydrogels (SAHs) for purification of brackish water represent a challenge. Here in, this work reports the unexpected effect achieved for water desalination when combining a small content of conducting polymer (CP), poly(3,4-ethylenedioxythiophene) (PEDOT), doped with poly(styrene sodium sulfonate) (PSS), with a well-known thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAAm). Less than 10% of CP is enough to achieve an evaporation rate of 3.45 ± 0.36 KMH, compared to the gel without the ionic polymer (1.75 ± 0.08 KMH). Furthermore, this work proves that the presence of alginate polysaccharide (ALG), which is a conventional reinforcement molecule applied to reach a stable entangled scaffold, is greatly favorable in compositions with 5 wt% of doped CP, reaching even a higher evaporation rate (4.50 ± 0.30 KMH). These results seem to be caused by a shrinkage effect named by the authors: “pudding effect.” The highly stable hydrogel double network demonstrated to have enough mechanical integrity for the hand manipulation of the gel in successive solar water evaporation cycles. Thus, the new system (with or without ALG) is a promising SAH candidate for self-portable water desalinators for domestic uses. The hydrogel preparation can be performed in one-pot reactor to customer up-scale size necessities., This project has received funding from the Grant PID2021-125257OB-I00,by MCIN/AEI/10.13039/501100011033 and by ERDF “A way of making Eu-rope,” by the European Union and from the Agència de Gestió d’Ajuts Uni-versitaris i de Recerca-AGAUR (2021SGR00387). J. Mingot also acknowl-edges the support of AGAUR for her PhD fellowship funding (Grant n°2021 FISDU 00287). A. Àgueda is a Serra Hunter Fellow (Government ofGeneralitat de Catalunya)., Peer Reviewed, Objectius de Desenvolupament Sostenible::6 - Aigua Neta i Sanejament, Postprint (published version)

This review presents a comprehensive update of the biopolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), emphasizing its production, properties, and applications. The overall biosynthesis pathway of PHBV is explored in detail, highlighting recent advances in production techniques. The inherent physicochemical properties of PHBV, along with its degradation behavior, are discussed in detail. This review also explores various blends and composites of PHBV, demonstrating their potential for a range of applications. Finally, the versatility of PHBV-based materials in multiple sectors is examined, emphasizing their increasing importance in the field of biodegradable polymers., Peer Reviewed, Postprint (published version)

As the most abundant renewable aromatic polymer on the planet, lignin is gaining growing interest in replacing petroleum-based chemicals and products. However, only <5 % of industrial lignin waste is revalorized in its macromolecular form as additives, stabilizing agents or dispersant and surfactants. Herein, revalorization of this biomass was achieved by implementing an environmentally-friendly continuous sonochemical nano- transformation to obtain highly concentrated lignin nanoparticles (LigNPs) dispersions for added-value material applications. With the aim to further model and control a large-scale ultrasound-assisted lignin nano- transformation, a two-level factorial design of experiment (DoE) was implemented varying the ultrasound (US) amplitude, flow rate, and lignin concentration. Size and polydispersity measurements together with the UV–Vis spectra of lignin recorded at different time intervals of sonication allowed to monitor and understand the sonochemical process on a molecular level. The light scattering profile of sonicated lignin dispersions showed a significant particle size reduction in the first 20 min, followed by moderate particle size decrease below 700 nm until the end of the 2 h process. The response surface analysis (RSA) of the particle size data revealed that the lignin concentration and sonication time were the most important factors to achieve smaller NPs. From a mechanistic point of view, a strong impact of the particle–particle collisions due to sonication seems to be responsible for the decrease in particle size and homogenization of the particle distribution. Unexpectedly, a strong interaction between the flow rate and US amplitude on the particle size and nanotransformation efficiency was observed, yielding smaller LigNPs at high amplitude and low flow rate or vice versa. The data derived from the DoE were used to model and predict the size and polydispersity of the sonicated lignin. Furthermore, the use of the NPs spectral process, This research was funded by the European Union under the framework of the projects BIOMAT (H2020-953270) and rLightBioCom (HORIZON-101091691). G. F. acknowledges Universitat Politècnica de Catalunya and Banco Santander for his PhD grant (113 FPI-UPC 2018)., Peer Reviewed, Postprint (published version)

Introduction: For some medical treatments associated with cancer, the invasion of organs is required, which must be done in a totally controlled way to obtain the expected results in the treatment. Today, most medical treatments make use of invasive therapies to combat the affected cancer tissues. Acting in this way also destroys those tissues not affected by the generation of tumor centers that confront the cancer tumor center to be treated. Methods: To ensure the objective of the treatment, doses of the drug to be administered in a little controlled and free via are used that are ultimately ineffective due to the high degradation of the active compound due to its non-existent stabilization and protection after its passage through the body and consequently possible episodes of phagocytization, responsible for the reticuloendothelial system. It is well known the side effects that one of the most promising anti-cancer molecules, doxorubicin, shows. This is a problem for its use, and one of the possibilities to avoid these desired behaviors, microencapsulation could be a possible approach. Result: Microencapsulation of drugs allows the design of micro-level structures capable of containing the active agent with sufficient protection and stabilization to be able to reach the target site with the highest possible concentration of drug to be able to be gradually released in its entirety and produce the desired effect in the therapy in a controlled way according to a previously studied kinetic profile, which will allow a type of treatment in which the therapy will be noninvasive due to the high degree of targeting selectivity that the microcapsule allows. Conclusion: The use of the amine groups present in the chitosan polymer's structure to increase or modify the molecular interactions with doxorubicin is a very interesting aspect that will be treated here. These interactions help to make possible the control and protection of the active principle, as it is shown in the q, Peer Reviewed, Postprint (author's final draft)

In order to exploit the pharmacological potential of natural bioactive molecules with low water solubility, such as curcumin, it is necessary to develop formulations, such as amorphous polymer dispersions, which allow a constant release rate and at the same time avoid possible toxicity effects of the crystalline form of the molecule under scrutiny. In this study, polymer dispersions of curcumin were obtained in PADAS, a biodegradable semicrystalline copolymer based on 1,12-dodecanediol, sebacic acid and alanine. The dispersions were fully characterized by means of differential scanning calorimetry and broadband dielectric spectroscopy, and the drug release profile was measured in a simulated body fluid. Amorphous homogeneous binary dispersions were obtained for curcumin mass fraction between 30 and 50%. Curcumin has significantly higher glass transition temperature Tg (˜ 347 K) than the polymer matrix (˜274-277 K depending on the molecular weight), and dispersions displayed Tg’s intermediate between those of the pure amorphous components, implying that curcumin acts as an effective antiplasticizer for PADAS. Dielectric spectroscopy was employed to assess the relaxation dynamics of the binary dispersion with 30 wt% curcumin, as well as that of each (amorphous) component separately. The binary dispersion was characterized by a single structural relaxation, a single Johari-Goldstein process, and two local intramolecular processes, one for each component. Interestingly, the latter processes scaled with the Tg of the sample, indicating that they are viscosity-sensitive. In addition, both the pristine polymer and the dispersion exhibited an interfacial Maxwell-Wagner relaxation, likely due to spatial heterogeneities associated with phase disproportionation in this polymer. The release of curcumin from the dispersion in a simulated body fluid followed a Fickian diffusion profile, and 51% of the initial curcumin content was released in 48 h., Peer Reviewed, Postprint (published version)

The delivery of drugs is a great challenge, since most of active pharmaceutical ingredients developed today are hydrophobic and poorly water soluble. From this perspective, drug encapsulation on biodegradable and biocompatible polymers can surpass this problem. Poly(gamma-glutamic acid) (PGGA), a bioedible and biocompatible polymer has been chosen for this purpose. Carboxylic side groups of PGGA have been partially esterified with 4-phenyl-butyl bromide, producing a series of aliphatic–aromatic ester derivatives with different hydrophilic–lipophilic balances. Using nanoprecipitation or emulsion/evaporation methods, these copolymers were self-assembled in a water solution, forming nanoparticles with average diameters between 89 and 374 nm and zeta potential values between -13.1 and -49.5 mV. The hydrophobic core containing 4-phenyl-butyl side groups was used for the encapsulation of an anticancer drug, such as Doxorubicin (DOX). The highest encapsulation efficiency was reached for a copolymer derived from PGGA, with a 46 mol % degree of esterification. Drug release studies carried out for 5 days at different pHs (4.2 and 7.4) indicated that DOX was released faster at pH 4.2, revealing the potential of these nanoparticles as chemotherapy agents., Peer Reviewed, Postprint (published version)

The objective of this work was to functionalize with microcapsules of untreated and treated polyester fabrics with plasma and ozone. Plasma treatment was carried out using a corona discharge at 200 W, 400 w and 800 W with a constant gap between electrode and roll of 4 mm. For ozone treatment, polyester samples were exposed for 20, 30, and 45 min to ozone production by low-pressure mercury lamps. After plasma or ozone, lavender oil microcapsules were immobilized onto fabric by a conventional pad–dry–cure process, using citric acid as a crosslinking agent. The microcapsules were produced by complex coacervation between chitosan and arabic gum, with lavender oil in emulsion. The release showed that the ozone on the surface of PET (polyester) increased the affinity for the microcapsules, resulting in a greater adhesion of the microcapsules and, as consequence, more amount of oil to be liberated. On the other hand, the effect of the plasma treatment was related to physical etching, without a chemical change, and does not interfere with the affinity of the microcapsule, whose external layer is a polar polymer. The delay in the oil release from PET treated with plasma can also be related to the pore formation, which could retain the microcapsules and difficult the release of the oil. Ozone proved to be a good surface treatment to enhance the functionalization of the textile substrate, so that the oil release with time can be greatly improved., Postprint (published version)

This work presents a novel nanoparticle-based thermosensor implant able to reveal the precise temperature variations along the polymer filaments, as it contracts and expands due to changes in the macroscale local temperature. The multimodal device is able to trace the position and the temperature of a polypropylene mesh, employed in abdominal hernia repair, by combining plasmon resonance and Raman spectroscopy with hydrogel responsive system. The novelty relies on the attachment of the biocompatible nanoparticles, based on gold stabilized by a chitosan-shell, already charged with the Raman reporter (RaR) molecules, to the robust prosthesis, without the need of chemical linkers. The SERS enhanced effect observed is potentiated by the presence of a quite thick layer of the copolymer (poly(N-isopropylacrylamide)-co-poly(acrylamide)) hydrogel. At temperatures above the LCST of PNIPAAm-co-PAAm, the water molecules are expulsed and the hydrogel layer contracts, leaving the RaR molecules more accessible to the Raman source. In vitro studies with fibroblast cells reveal that the functionalized surgical mesh is biocompatible and no toxic substances are leached in the medium. The mesh sensor opens new frontiers to semi-invasive diagnosis and infection prevention in hernia repair by using SERS spectroscopy. It also offers new possibilities to the functionalization of other healthcare products., Peer Reviewed, Postprint (author's final draft)

Electrochemically responsive hydrogel networks have been obtained using printable inks made of a biopolymer, alginate (Alg), and an inorganic 2D material, MXene (titanium carbide, Ti3C2Tx) nanosheets. While MXene offers an electrically conductive pathway for electron transfer and Alg provides an interconnected framework for ion diffusion, the printed nanocomposite results, after gelation, in an extended active interface for redox reactions, being an ideal framework to design and construct flexible devices for biomedical applications. In this work, after characterization, we demonstrate that hydrogels obtained by cross-linking printed Alg/MXene inks exhibit great potential for bioelectronics. More specifically, we prove that flexible Alg/MXene hydrogels act as self-supported electroactive electrodes for the electrochemical detection of bioanalytes, such as dopamine, with a performance similar to that achieved using more sophisticated electrodes, as for example those containing conducting polymers and electrocatalytic gold nanoparticles. In addition, Alg/MXene hydrogels have been successfully used to regulate the release of a previously loaded broad spectrum antibiotic (chloramphenicol) by electrical stimulation., Postprint (author's final draft)

Virtually, all implantable medical devices are susceptible to infection. As the main healthcare issue concerning implantable devices is the elevated risk of infection, different strategies based on the coating or functionalization of biomedical devices with antiseptic agents or antibiotics are proposed. In this work, an alternative approach is presented, which consists of the functionalization of implantable medical devices with sensors capable of detecting infection at very early stages through continuous monitoring of the bacteria metabolism. This approach, which is implemented in surgical sutures as a representative case of implantable devices susceptible to bacteria colonization, is expected to minimize the risk of worsening the patient's clinical condition. More specifically, non-absorbable polypropylene/polyethylene (PP/PE) surgical sutures are functionalized with conducting polymers using a combination of low-pressure oxygen plasma, chemical oxidative polymerization, and anodic polymerization, to detect metabolites coming from bacteria respiration. Functionalized suture yarns are used for real-time monitoring of bacteria growth, demonstrating the potential of this strategy to fight against infections., Postprint (published version)

Antibodies are highly selective and sensitive, making them the gold standard for recognition affinity tools. However, their production cost is high and their downstream processing is time-consuming. Molecularly imprinted polymers (MIPs) are tailor-made by incorporating specific molecular recognition sites in their structure, thus translating into receptor-like activity mode of action. The interest in molecular imprinting technology, applied to biomacromolecules, has increased in the past decade. MIPs, produced using biomolecules as templates, commonly referred to as “plastic antibodies” or “artificial receptors”, have been considered as suitable cheaper and easy to produce alternatives to antibodies. Research on MIPs, designed to recognize proteins or peptides is particularly important, with potential contributions towards biomedical applications, namely biosensors and targeted drug delivery systems. This mini review will cover recent advances on (bio)molecular imprinting technology, where proteins or peptides are targeted or mimicked for sensing and therapeutic applications. Polymerization methods are reviewed elsewhere, being out of the scope of this review. Template selection and immobilization approaches, monomers and applications will be discussed, highlighting possible drawbacks and gaps in research., Peer Reviewed, Postprint (author's final draft)

Biofilms are a global health concern responsible for 65 to 80% of the total number of acute and persistent nosocomial infections, which lead to prolonged hospitalization and a huge economic burden to the healthcare systems. Biofilms are organized assemblages of surface-bound cells, which are enclosed in a self-produced extracellular polymer matrix (EPM) of polysaccharides, nucleic acids, lipids, and proteins. The EPM holds the pathogens together and provides a functional environment, enabling adhesion to living and non-living surfaces, mechanical stability, next to enhanced tolerance to host immune responses and conventional antibiotics compared to free-floating cells. Furthermore, the close proximity of cells in biofilms facilitates the horizontal transfer of genes, which is responsible for the development of antibiotic resistance. Given the growing number and impact of resistant bacteria, there is an urgent need to design novel strategies in order to outsmart bacterial evolutionary mechanisms. Antibiotic-free approaches that attenuate virulence through interruption of quorum sensing, prevent adhesion via EPM degradation, or kill pathogens by novel mechanisms that are less likely to cause resistance have gained considerable attention in the war against biofilm infections. Thereby, nanoformulation offers significant advantages due to the enhanced antibacterial efficacy and better penetration into the biofilm compared to bulk therapeutics of the same composition. This review highlights the latest developments in the field of nanoformulated quorum-quenching actives, antiadhesives, and bactericides, and their use as colloid suspensions and coatings on medical devices to reduce the incidence of biofilm-related infections., Peer Reviewed, Postprint (published version)

Functional hydrogels are three-dimensional polymeric networks with potential applicability in the field of wearable electronics. However, hydrogels are often used to develop devices with only one functionality. In this work, a multifunctional hydrogel consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), alginate (Alg), carbon nanoparticles (CNPs), and manganese oxide has been manufactured for devices that can simultaneously store energy (supercapacitor) and sense temperature. The Alg and PEDOT interpenetration allows for obtaining a flexible and electrically conductive hydrogel with an open and interconnected porous structure. The incorporation of CNPs improves electrical conductivity and confers synergies with manganese oxide, which provide energy storage capability. Furthermore, the resistance of the hydrogel varies linearly with the temperature, this behavior being observed consistently and without hysteresis throughout consecutive heating and cooling cycles. Thus, the PEDOT/Alg/CNP/MnO2 hydrogel shows good capacitance (42 mF cm–2), capacitance retention (87%), and good temperature sensitivity (-1.05% °C–1)., Peer Reviewed, Postprint (author's final draft)

Temperature-sensitive (thermosensitive) hydrogels, which are part of the family of stimulus-sensitive hydrogels, consist of water-filled polymer networks that display a temperature-dependent degree of swelling. Thermosensitive hydrogels, which can undergo phase transition or swell/deswell as temperature changes, have great potential in various technological and biomedical purposes for a number of reasons: their temperature response is revesible, hydrogels are stable and easy to prepare, they can be biocompatible and also be suitably combined with other organic and inorganic materials, resulting in new materials with outstanding properties. Among thermosensitive hydrogels poly(N-isopropylacrylamide) (PNIPAAm) is the most extensively studied because it brings together the best properties of these materials. Consequently, in the last few years a wide number of applications and new chemical processes to prepare PNIPAAm and their derivatives are being proposed. The objective of this review is to summarize fundamentals of thermosensitive hydrogels and recent advances in preparation and both technological and biomedical applications of thermosensitive hydrogel, with special focus on PNIPAAm and their derivatives. Special attention has been given to the discussion of challenges and future research perspectives based on new horizons not yet considered., Peer Reviewed, Postprint (published version)

Essential Oils (EOs) are a substance composed of two phases. A liquid and volatile substance that has aromatic, antibacterial, antioxidant. The properties of EOs are not new to humanity. Indeed, these began to take a role from the first civilizations (Egyptian civilization). Where EOs used as preservatives and flavourings. Nowadays, the use of the EOs is the same. Avoid the growth of bacteria and viruses (theoretical) in food, the contact surface (chairs of the bus), tables, fabrics (clothes). During these last years, the industrial world took the relevance of the microencapsulation technique. This technique pretends to capture the EOs to reach two main objectives. First, contain all his active compounds into a microcapsule to prevent the degradation of the environment. Second, release control into the media, contact surface, or fabrics. Microencapsulation is a beneficial technology to improve fields of biomedicine and the food industry. Besides, the impregnation of these microcapsules on fabrics can develop a lot of new properties. Indeed, the antibacterial and antioxidant properties. The amount of these properties requires an accurate and meticulous methodology. The formation of the microcapsules is very complicated to explain from one point of view. Therefore, it is necessary to collect all the available data. Nevertheless, the research count with very sophisticated equipment, which can provide us with very accurate results. Nanosizer, Spectrophotometer, SEM. The meaning of this research is to make sure if it is possible to control either the diffusion of the EOs and his chemist properties (diameter and morphology). Simple coacervation of microcapsules of ß-cyclodextrin (B-CD) with lavender (L) is the technique that we will follow at the beginning of this research. These simple microcapsules will be impregnated in different fabrics: Polyester (PET), Cotton (COT), and Polyamide (PA). After his impregnation, we must wait until dry in the ambient and make the drug d, Peer Reviewed, Postprint (published version)

Permanently polarized hydroxyapatite (p-HAp) has been reported as a feasible green alternative to conventional catalysts for the selective conversion of CO2 into highly valuable chemical products. However, structural control and enhanced electrical properties achieved on p-HAp clearly contrast with other reported catalytic systems, where hydroxyapatite mainly acts as a support receiving much less attention. In this work we take advantage of the knowledge obtained on p-HAp to develop an HAp-based catalytic system composed of TiO2 nanoparticles deposited on p-HAp. It is important to stress that p-HAp is not only considered as a mechanical support but has been put in the spotlight for catalyst preparation and as an active catalytic part. Therefore, the use of p-HAp in this system has unveiled exceptional synergies with TiO2 attributed to the enhanced electrical properties of p-HAp, capable of attracting the photo-electrons generated in TiO2 nanoparticles avoiding electron–hole recombination. CO2 fixation reactions carried out under mild conditions (120 °C, 6 bar and under UV exposure) result in complete selectivity control of the C2 products, shifting from ethanol (201 µmol gcatalyst-1) for p-HAp alone to acetic acid (381 µmol gcatalyst-1) when TiO2 nanoparticles are loaded in the system. Considering the challenging CO2 activation energy and the high control of the selectivity achieved, we do believe that this novel approach can be considered as a starting point to explore other systems and reactions where control of the crystal structure and the enhanced electrical properties of HAp can play a crucial role in the final products, reaction conditions, yields and selectivities., Peer Reviewed, Postprint (author's final draft)