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The current research study deals with the design and investigation of novel bioinspired and biocompatible GO-COOH decorated hybrid polymeric scaffolds with nanofibrous architecture as biomaterials with highly appropriate features for functional restoration of damaged tissue. Gelatin and alginate, two biobased-polymers with excellent biocompatibility, high microenvironment biomimicry and ability for proper guidance of cell development in combination with carboxylated graphene oxide (GO-COOH), embody the matrix of electrospun hybrid scaffolds. The underlying principle is based on various types of interactions that can take place between the functionalities of the system's entities (proved by DLS) and their synergy in improving the structural integrity, mechanical tailorability and biological performances of the new nanofibrous GO-COOH decorated hybrid scaffolds. The nanofibrous structure along with the presence of GO-COOH are established by SEM. The new covalent bonds formed between various functionalities of the protein-polysaccharide-GO-COOH system are proved by FTIR and XPS. The physico-chemical state of GO-COOH lattices within the hybrid structures is investigated by Raman spectrometry. The interpenetrated network of bicomponent structures determines a 10-fold increase of Young's modulus as compared to monocomponent counterparts while the dispersion of GO-COOH significantly increases the elasticity of materials. The biological results (MTT and LDH assays) indicate a good cytocompatibility of crosslinked bicomponent AGS scaffolds; the metabolic cellular activity is substantially improved following the GO-COOH addition, suggesting that GO-COOH can support the cell adhesion, growth and proliferation.

3D printing technology has changed academia and industry perception regarding the course of evolution in the manufacturing of customizable products, paving the way towards refined patient treatment plans that can best fit individual needs. Coupling 3D printing with suitable biomaterial and CT-scan personalized implants resembling complex tissue architecture and able to sustain cell seeding and proliferation can be fabricated. This review aims to provide a comprehensive overview of 3D printing available techniques and aspects related to the standards of congruity between material and procedure. The present state of development in 3D printing materials is also assessed with the focus on graphene and graphene composite inks and the optimization of these formulations for various 3D printing methods. Recent advances in printing with cell containing inks and the new concept of 4D printing are also addressed. Biosensor fabrication benefits from graphene inks and 3D printing are highlighted and recent reports on user-friendly 3D printed graphene biosensors for biomolecule detection have also been reviewed. Overall, the manuscript outlines the benefits and limitation of 3D printing techniques and graphene based inks for biomedical purposes and their potential impact in healthcare.

The structure and biocompatibility analysis of a hydrogel based on cellulose nanofibers (CNFs) combined with alginate/pectin (A.CNF or P.CNF) and enriched with 1% or 5% 5-FU revealed more favorable properties for the cellular component when pectin was dispersed within CNFs. 5-Fluorouracil (5-FU) is an antimetabolite fluoropyrimidine used as antineoplastic drug for the treatment of multiple solid tumors. 5-FU activity leads to caspase-1 activation, secretion and maturation of interleukins (IL)-1, IL-18 and reactive oxygen species (ROS) generation. Furthermore, the effects of embedding 5-FU in P.CNF were explored in order to suppress breast tumor cell growth and induce inflammasome complex activation together with extra- and intracellular ROS generation. Exposure of tumor cells to P.CNF/5-FU resulted in a strong cytotoxic effect, an increased level of caspase-1 released in the culture media and ROS production—the latter directly proportional to the concentration of anti-tumor agent embedded in the scaffolds. Simultaneously, 5-FU determined the increase of p53 and caspase-1 expressions, both at gene and protein levels. In conclusion, P.CNF/5-FU scaffolds proved to be efficient against breast tumor cells growth due to pyroptosis induction. Furthermore, biocompatibility and the potential to support human adipose-derived stem cell growth were demonstrated, suggesting that these 3D systems could be used in soft tissue reconstruction post-mastectomy.

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.

This research study reports the development of chitosan/carboxylated graphene oxide (CS/GO-COOH) composite scaffolds with nanofibrous architecture using the electrospinning method. The concept of designed composite fibrous material is based on bringing together the biological properties of CS, mechanical, electrical, and biological characteristics of GO-COOH with the versatility and efficiency of ultra-modern electrospinning techniques. Three different concentrations of GO-COOH were added into a chitosan (CS)-poly(ethylene oxide) (PEO) solution (the ratio between CS/PEO was 3/7 (w/w)) and were used in the synthesis process of composite scaffolds. The effect of GO-COOH concentration on the spinnability, morphological and mechanical features, wettability, and biological properties of engineered fibrous scaffolds was thoroughly investigated. FTIR results revealed the non-covalent and covalent interactions that could take place between the system’s components. The SEM micrographs highlighted the nanofibrous architecture of scaffolds, and the presence of GO-COOH sheets along the composite CS/GO-COOH nanofibers. The size distribution graphs showed a decreasing trend in the mean diameter of composite nanofibers with the increase in GO-COOH content, from 141.40 nm for CS/PG 0.1% to 119.88 nm for CS/PG 0.5%. The dispersion of GO-COOH led to composite scaffolds with increased elasticity, the Young’s modulus of CS/PG 0.5% (84 ± 4.71 MPa) was 7.5-fold lower as compared to CS/PEO (662 ± 15.18 MPa, p &lt, 0.0001). Contact angle measurements showed that both GO-COOH content and crosslinking step influenced the surface wettability of scaffolds, leading to materials with ~1.25-fold higher hydrophobicity. The in vitro cytocompatibility assessment showed that the designed nanofibrous scaffolds showed a reasonable cellular proliferation level after 72 h of contact with the fibroblast cells.

The development of materials for 3D printing adapted for tissue engineering represents one of the main concerns nowadays. Our aim was to obtain suitable 3D-printed scaffolds based on methacrylated gelatin (GelMA). In this respect, three degrees of GelMA methacrylation, three different concentrations of GelMA (10%, 20%, and 30%), and also two concentrations of photoinitiator (I-2959) (0.5% and 1%) were explored to develop proper GelMA hydrogel ink formulations to be used in the 3D printing process. Afterward, all these GelMA hydrogel-based inks/3D-printed scaffolds were characterized structurally, mechanically, and morphologically. The presence of methacryloyl groups bounded to the surface of GelMA was confirmed by FTIR and 1H-NMR analyses. The methacrylation degree influenced the value of the isoelectric point that decreased with the GelMA methacrylation degree. A greater concentration of photoinitiator influenced the hydrophilicity of the polymer as proved using contact angle and swelling studies because of the new bonds resulting after the photocrosslinking stage. According to the mechanical tests, better mechanical properties were obtained in the presence of the 1% initiator. Circular dichroism analyses demonstrated that the secondary structure of gelatin remained unaffected during the methacrylation process, thus being suitable for biological applications.

In this work fully biomass-based hydrogels were developed using a naturally occurring vegetable hydrocolloid co-mingled with wood-derived nanocellulose fibrils. Two distinct types of hydrocolloids have been considered: a seaweed-derived biopolymer (alginate) and a plant-derived biopolymer (pectin). To attain nano-structured binary hydrogels, surface-functionalized cellulose nanofibrils (CNFs) bearing carboxyl groups were employed. This study addresses a non-conventional approach of physical gelation that takes place in acidic conditions (pH

International audience; In the context of global issues concerning pathogen contamination of surface and ground waters, this pioneering study describes the fabrication of screen-printed carbon electrodes modified with polymers molecularly imprinted with lipopolysaccharide in an attempt to detect endotoxins derived from specific Gram-negative bacteria. The biosensors detected lipopolysaccharides derived from Pseudomonas Aeruginosa with high specificity, relative to control sensors, while the response to the same endotoxin derived from Escherichia coli was quite different.

The bioactivity of scaffolds represents a key property to facilitate the bone repair after orthopedic trauma. This study reports the development of biomimetic paste-type inks based on wollastonite (CS) and fish gelatin (FG) in a mass ratio similar to natural bone, as an appealing strategy to promote the mineralization during scaffold incubation in simulated body fluid (SBF). High-resolution 3D scaffolds were fabricated through 3D printing, and the homogeneous distribution of CS in the protein matrix was revealed by scanning electron microscopy/energy-dispersive X-ray diffraction analysis (SEM/EDX) micrographs. The bioactivity of the scaffold was suggested by an outstanding mineralization capacity revealed by the apatite layers deposited on the scaffold surface after immersion in SBF. The biocompatibility was demonstrated by cell proliferation established by MTT assay and fluorescence microscopy images and confirmed by SEM micrographs illustrating cell spreading. This work highlights the potential of the bicomponent inks to fabricate 3D bioactive scaffolds and predicts the osteogenic properties for bone regeneration applications.

Compared to the classical systemic administration, the local drug release has some advantages, such as lack of systemic toxicity and associated side effects, increased patient compliance, and a low rate of bacterial resistance. Biopolymers are widely used to design sustained drug delivery systems and biomaterials for tissue engineering. Type II collagen is the indispensable component in articular cartilage and plays a critical role in the growth and proliferation process of chondrocytes. Thus, type II collagen has drawn more attention and interest in the treatment and research of the cartilage regeneration. The aim of this study was to obtain, characterize, and optimize the microcapsules formulation based on type II collagen, sodium alginate, and sodium carboxymethyl cellulose loaded with doxycycline as an antibiotic model drug that could be incorporated further in hydrogels to improve the localized therapy of septic arthritis. The new synthesized microcapsules were assessed by spectral (FT-IR), morphological (optical microscopy), and biological analysis (enzymatic biodegradation, antimicrobial activity). The size distribution of the obtained microcapsules was determined using optical microscopy. The drug encapsulation efficiency was also determined. To optimize the microcapsules&rsquo, composition, some physical-chemical and biological analyses were subjected to an optimization technique based on experimental design, response surface methodology, and the Taguchi technique, and the adequate formulations were selected. The results obtained recommend these new microcapsules as promising drug systems to be further incorporated in type II collagen hydrogels used for septic arthritis.

Aiming to address the issue of poor bioavailability of most anti-tumor medicines against colorectal cancer, we developed a targeted anticancer nanocarrier using biocarriers able to both bind and easily release their load in a controlled manner. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) carriers were obtained via the emulsification-diffusion method, loaded with 5-fluorouracil and then characterized in terms of particle morphology and size (SEM, DLS), drug uptake and release. The cytotoxic potential of the 5-fluorouracil-loaded polymer nanocarriers on human adenocarcinoma cells (HT-29 cell line) was investigated. The in vitro studies clearly demonstrated that while the nanocarriers themselves slightly alter HT-29 cell viability, when loaded with 5-fluorouracil they significantly decrease cell viability, suggesting that the polymer itself exhibits low cytotoxicity and the drug-loaded carrier acts in an efficient manner to kill HT-29 human adenocarcinoma cells.

The paper focuses on the obtaining of novel nanocomposite hydrogels based on polyacrylamide and layered double hydroxides (LDHs) modified with double bonds. The modification of LDH clay was investigated by FTIR, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses. Mechanical properties of the nanocomposite hydrogels were employed by compression and rheological measurements. The formation of exfoliated and intercalated structures was evidenced in transmission electron microscopy (TEM). Chemical cross-linking of hydrogels using both classical cross-linker and modified clay was an efficient method to improve the mechanical properties of novel nanocomposite hydrogels. These hydrogels with improved mechanical properties could be further tested for biomedical applications such as tissue engineering.

This study proposes the synthesis of a new type of hybrid polymer – vegetable oil nanoparticles (HPONP) as system for lipophilic drug delivery and controlled release. Poly (lactic-co-glycolic) acid (PLGA) and Nigella sativa vegetable oil (NSO) were used to obtain HPONP, employing Izohidrafural (IHF) as lipophilic drug reference. Scanning Electron Microscopy presented perfect spherical structures like liposome of HPONP. The narrow sized (d = 139 nm, PdI = 0.18) HPONP registered good encapsulation capacity (56.8%). The release studies highlighted that the oil incorporation influenced the ability of nanocarrier to discharge the drug in a more sustained manner. According to IC50 and cytotoxicity data, the oil dispersion within the nanocarrier matrix decreased the cytotoxicity of HPONP-IHF as compared to standard PLGA-IHF. Biological assessment revealed a noteworthy antibacterial activity of HPONP-IHF against S. aureus (MIC 4.9 μg/mL), double compared to IHF (MIC 11.7 μg/mL) and five or ten times more active than PLGA-IHF or reference drug - Nitrofurantoin.

Organic-inorganic nanocomposites were designed by combining a commercial epoxy resin (diglycidyl ether of bisphenol A - DER) and a multi-thiol crosslinking agent with a “clickable” polyhedral oligomeric silsesquioxane (POSS) compound. 1-methylimidazole was employed as a catalyst to yield highly efficient thiol-Michael addition reaction materials. The equivalent ratio between epoxy: thiol was maintained 1:1 in all the formulations and therefore the homopolymerization reaction of epoxy resin is unlikely to occur. The synergistic effect of the thiol compound and mono-functionalized POSS bearing one epoxy/thiol reactive group on the curing process was investigated in detail. We assume that the mechanistic pathway of the thiol-epoxy click-reaction increases in complexity due to the introduction of reactive POSS in the system. The incorporation of mono-epoxy or mono-thiol POSS in the thiol–epoxy organic host leads to distinct thermo-mechanical behavior of the crosslinked networks due to the fact that the POSS compound will chemically interact in the click reaction.

The present work is aimed to develop new composite films based on pectin and functionalized graphene oxide (GOf) by using a simple casting method. The non-covalent functionalization of graphene oxide (GO) was performed by using a non-ionic surfactant (Tergitol NP9) and therefore the interaction between GO and the polymer matrix was significantly enhanced. X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS) and Fourier-transform infrared (FT-IR) were used to prove the GO functionalization. The functionalization was evidenced also by Raman spectrometry and thermogravimetric analysis (TGA). According to the mechanical tests, an improvement of the Young’s modulus was recorded even at low loading of GOf within the pectin matrix which indicates a strong interaction between the polymer and GOf. By incorporation of GOf within pectin a modification of the morphology of the composite materials was observed by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analysis.

In this study, different dithiol/dimethacrylate formulations ± octamethacryl-polyhedral oligomeric silsesquioxanes (POSS) were synthesized and fully characterized in terms of structural, morphological, and thermostability features. The obtained results indicate that the incorporation of both dithiol and octamethacryl-POSS nanofillers within dimethacrylate matrix exhibits a significant influence on the surface chemistry, polymerization kinetics, thermostability, and thermomechanical properties of the resulting networks. Kinetic analysis showed that the presence of dithiol compound improves the conversion degree of the final dithiol/dimethacrylate networks, while thermal and thermomechanical analyses exhibit that octamethacryl-POSS produces nano-hybrids with enhanced thermostability and storage moduli.

New porous Chitosan-Poly(vinyl alcohol)/graphene oxide (CHT-PVA/GO) biocomposites scaffolds were obtained by a freeze drying method. The structural and morphology properties of the scaffolds were investigated. Fourier transmission infrared (FTIR) spectra confirmed the presence of GO into the biopolymer matrices. Scanning Electron Microscopy (SEM) images show a highly interconnected porosity for the composites with GO incorporated within the polymer matrices. Further, the water uptake capacity and the enzyme degradation behavior were conducted. The biocomposite ability to form hydroxyapatite (HA) crystals and therefore bone regeneration potential was studied. SEM shows that all the samples are covered with a mineral phase made of micro globule needle type. The presence of HA crystals on the surface was proved by X-ray Diffraction (XRD) where a large number of the characteristic peaks of HA were observed, the average size of individual crystallite being dependent on GO amount.

The goal of this paper was to study the modification of porous clay heterostructures (PCHs) with various silane coupling agents. Two commercial coupling agents (3-aminopropyl-triethoxysilane (APTES) and 3-glycidoxypropyl-trimethoxysilane (GPTMS)) with different functional groups (amine and epoxy groups) were used as modifying agents for the PCHs functionalization. The functionalization of PCH with APTES and GPTMS was evaluated by Fourier transform infrared (FTIR) spectrometry, thermogravimetric analysis (TGA), X-Ray Diffractions (XRD) and BET Analysis. FTIR spectra of modified PCHs confirmed the presence of characteristic peaks of silane coupling agents. TGA results highlighted an increase of weight loss for the modified PCHs that was assigned to the degradation of silane coupling agents (APTES and GPTMS) attached to the PCHs. The XRD results showed that the structure of modified PCHs was influenced by the type of the silane coupling agent. The functionalization of PCHs with silane coupling agents was also confirmed by BET analysis. Textural parameters (specific surface area (SBET), total pore volume (Vt )) suggested that the modified PCHs exhibit lower values of SBET and a significant decrease of total pore volume than unmodified PCHs.

Ephedrine is an illicit drug, classified as precursor for methamphetamine, which is also used as stimulant, appetite suppressant, decongestant or asthma. In this study, novel molecularly imprinted polymer (MIP) films were prepared by sol-gel derived techniques, using N-(2-aminoethyl)-3-aminopropyltrimethoxysilane as functional monomer, to recognize ephedrine from aqueous solutions. The films were obtained by air-spraying the precursor solutions, with various concentrations of monomer and template, on glass supports. Infrared, thermogravimetry, ellipsometry, optic and atomic force microscopy analyzes of films provided information regarding the effect of molecular imprinting upon the physical properties of films. Further on, batch rebinding evaluation indicated that thinner films present high affinity for ephedrine, resulting in 6.2 imprinting factor after 15 minutes of contact, which attests the ability of the novel MIP films to recognize and rebind ephedrine.

Due to the reduced ability of most harmed tissues to self-regenerate, new strategies are being developed in order to promote self-repair assisted or not by biomaterials, among these tissue engineering (TE). Human adipose-derived mesenchymal stem cells (hASCs) currently represent a promising tool for tissue reconstruction, due to their low immunogenicity, high differentiation potential to multiple cell types and easy harvesting. Gelatin is a natural biocompatible polymer used for regenerative applications, while nanodiamond particles (NDs) are used as reinforcing nanomaterial that might modulate cell behavior, namely cell adhesion, viability, and proliferation. The development of electrospun microfibers loaded with NDs is expected to allow nanomechanical sensing due to local modifications of both nanostructure and stiffness. Two aqueous suspensions with 0.5 and 1% w/v NDs in gelatin from cold water fish skin (FG) were used to generate electrospun meshes. Advanced morpho- and micro-structural characterization revealed homogeneous microfibers. Nanoindentation tests confirmed the reinforcing effect of NDs. Biocompatibility assays showed an increased viability and proliferation profile of hASCs in contact with FG_NDs, correlated with very low cytotoxic effects of the materials. Moreover, hASCs developed an elongated cytoskeleton, suggesting that NDs addition to FG materials encouraged cell adhesion. This study showed the FG_NDs fibrous scaffolds potential for advanced TE applications.

The aim of our work is to prepare mucoadhesive particles with biopolymers and 5-Aminosalicylic acid (5ASA) using the ionotropic gelation technique to ensure a controlled drug release at the colon level with potential applications in the treatment of intestinal bowel disease (IBD). The preparation of particles through the crosslinking of Chitosan (CS) with sodium tripolyphosphate (TPP) using different mass ratios and the influence of the k-Carrageenan (kCG) layer were studied. UV–VIS spectrometry was employed to assess encapsulation efficiency and drug release profile of 5ASA. The particles were investigated using FT-IR spectrometry for chemical characterization and the DLS results highlighted a monodisperse particle size distribution. The morphology of the polymeric beads was investigated using micro-computer tomography (µCT) and Scanning Electron Microscopy (SEM). Particles based on Chitosan and k-Carrageenan were able to incorporate and preserve 5ASA in an acidic and alkaline medium. The 5ASA loaded polymeric particles obtained after immersion for 1 h in kCG solution exhibited the lowest release rate in pH = 1.2. Biocompatibility studies performed on all of the particles displayed a good viability for the CCD 841 CoN cells and low cytotoxicity. All of the results have shown that these new biomaterials could be a versatile platform of targeted carriers with potential applications in inflammatory bowel disease treatment.

This study deals with the design and comprehensive evaluation of novel hydrogels based on whey protein isolate (WPI) for tissue regeneration. So far, WPI has been considered mainly as a food industry by-product and there are very few reports on the application of WPI in tissue engineering (TE). In this work, WPI-based hydrogels were modified with bioactive glass (BG), which is commonly used as a bone substitute material. Ready-to-use, sterile hydrogels were produced by a simple technique, namely heat-induced gelation. Two different concentrations (10 and 20% w/w) of sol–gel-derived BG particles of two different sizes (2.5 and

Unilateral nuclear magnetic resonance (NMR) and imaging thermal microscopy (imageMHT) were performed on newly obtained and artificially aged vegetable tanned leathers. Calf and sheep leathers tanned with vegetal extracts of mimosa bark, quebracho and chestnut wood were compared. Ageing was simulated by exposing the leather samples to heating at 70 °C in controlled atmosphere at 30% relative humidity and irradiating them with 4000 lx in the visible light region for 8, 16, 32 and 64 days. Proton spin-lattice relaxation times T 1 and effective spin-spin relaxation times T 2eff were measured at room temperature and their trend variation compared with the corresponding variations of shrinkage temperature T s and total length of shrinkage interval measured by imageMHT. Newly obtained leather displayed different proton relaxation times and shrinkage temperatures depending on both the collagen origin and tannin type. Effective spin-spin relaxation values shown to be discriminative for collagen origin and sensitive to the cross-linking degree, whereas spin-lattice relaxation values were more sensitive to the tannin type. Both NMR relaxation times were sensitive to the changes in the water dynamics upon ageing due to the formation of collagen damaged intermediate states and shown a sudden change when the tannin matrix was depleted (e.g. de-tanning).

The new approach was to grow benzoxazine rings on graphene oxide chemically modified. This paper describes the preparation of benzoxazine-functionalized graphene oxide using the activation of the carboxylic groups from graphene oxide (GO) surface by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-Hydroxysuccinimide system (EDC/NHS) and the chlorination method employing SOCl 2 respectively. The carboxylic groups from GO surface were treated with tyramine for synthesizing the hydroxyl groups that will further react with benzylamine and formaldehyde in order to form the benzoxazine rings. Finally a nano structure with strong covalent bonds between the graphene sheets and the polybenzoxazine chains was achieved. The formation of multi-benzoxazine functionalized graphene oxide was checked by FT-IR, 1 HNMR, TGA, Raman spectrometry, XRD, HR-TEM and XPS analysis.

Lately, renewable resources received great attention in the macromolecular compounds area, regarding the design of the monomers and polymers with different applications. In this study the capacity of several modified vegetable oil-based monomers to build competitive hybrid networks was investigate, taking into account thermal and mechanical behavior of the designed materials. In order to synthesize such competitive nanocomposites, the selected renewable raw material, camelina oil, was employed due to the non-toxicity and biodegradability behavior. General properties of epoxidized camelina oil-based materials were improved by loading of different types of organic-inorganic hybrid compounds – polyhedral oligomeric silsesquioxane (POSS) bearing one (POSS1Ep) or eight (POSS8Ep) epoxy rings on the cages. In order to identify the chemical changes occurring after the thermal curing reactions, FT-IR spectrometry was employed. The new synthesized nanocomposites based on epoxidized camelina oil (ECO) were characterized by dynamic mechanical analyze and thermogravimetric analyze. The morphology of the ECO-based materials was investigate by scanning electron microscopy and supplementary information regarding the presence of the POSS compounds were establish by energy dispersive X-ray analysis and X-ray photoelectron spectroscopy. The smooth materials without any separation phase indicates a well dispersion of the Si–O–Si cages within the organic matrix and the incorporation of this hybrid compounds into the ECO network demonstrates to be a well strategy to improve the thermal and mechanical properties, simultaneously.

Fluorinated epoxy resins (FERs) were extensively studied for applications in electronic packaging, optical waveguides, and antifouling coatings. This research focuses on the synthesis and characterization of FER following a polycondensation reaction between fluorinated bisphenol and epichlorohydrin. Cure reaction was monitored using dispersive Raman spectroscopy and by calculation of the oxirane groups conversion. After one short postcuring stage, the decomposition temperatures of fluoroepoxy showed increased values with 28–35°C for the samples cured at 50°C. The resultant materials showed excellent fracture morphology, while the presence of fluorine was revealed by energy-dispersive X-ray and X-ray photoelectron spectroscopic techniques. Hydrophobic surface was evidenced through the surface energy resulted from contact angle measurements.

This article reports the synthesis and characterization of several types of organic–inorganic nanocomposites based on epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) reinforced with 2, 5, or 10 wt% polyhedral oligomeric silsesquioxanes (POSS) bearing one glycidyl (1GE-POSS) or eight glycidyl(8GE-POSS) groups. The morphological features of the studied samples were established through atomic force microscopy, contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy, and it was demonstrated that 8GE-POSS is well dispersed within the polymer matrix, while 1GE-POSS exhibits a high tendency to form aggregates. Differential scanning calorimetry (DSC) and Fourier transform infrared resonance (FTIR) measurements are used to follow the curing behavior and to study the polymerization kinetics of epoxy groups. As evidenced by DSC and FTIR results, the inclusion of 8GE-POSS within the polymer matrix leads to a lower epoxy polymerization rate of the resulted nanocomposites than those reinforced with 1GE-POSS. The dynamic mechanical analysis results revealed that the thermomechanical properties are gradually improved with increasing of 8GE-POSS content due to the higher cross-linking density.

This study highlights the preparation and characterization of new polysulfone/carboxylic acid functionalized graphene (PSF/G-COOH) porous composite films. Materials structure, morphology, topography, hydrophilic–hydrophobic character, as well as thermal, mechanical and biological behavior were thoroughly evaluated. Raman spectrometry, X-ray diffraction and transmission electron microscopy evidenced the formation of homogenous configurations, with well-dispersed G-COOH layers within the PSF matrix. Both film sides were found to develop larger pores in the presence of G-COOH, whereas changes of selective layer thickness and macrovoids shape were also observed. Profilometry emphasized a smoothing effect imposed by G-COOH on both surfaces, ∼50% reduction of surface roughness was computed for 2 wt.% G-COOH. No significant vary was noticed for water contact angle, whereas biocomposites thermal and mechanical stability were found to be positively related to G-COOH concentrations. Biocompatibility and cell cytoskeleton assessments revealed good biocompatibility and emphasized cells affinity for G-COOH rich areas.

Shape fidelity and integrity are serious challenges in the 3D printing of hydrogel precursors, as they can influence the overall performance of 3D scaffolds. This work reports the development of superconcentrated inks based on sodium alginate and fish gelatin as an appealing strategy to satisfy such challenges and dictate the quality of the printed scaffolds, without using crosslinking strategies during 3D printing. SEM micrographs and micro-CT images indicate the homogeneous distribution of the polysaccharide in the gelatin-based matrix, suggesting its potential to act as a reinforcing additive. The high concentration of gelatin aqueous solution (50 wt%) and substantial incorporation of alginate have facilitated the highly accurate printability and influence the in vitro stability and mechanical properties of the printed scaffolds. An improvement of the stiffness is dictated by the increase of alginate concentration from 20 wt% to 25 wt%, and an increase of Young modulus with about 46% is reached, confirming the reinforcing effect of polysaccharide. This study highlights the potential of paste-type inks to provide high resolution 3D printed structures with appealing structural and dimensional stability, in vitro degradability and mechanical properties for biomedical applications.

This paper reports the electrospinning fabrication of flexible nanostructured tubular scaffolds, based on fish gelatin (FG) and nanodiamond nanoparticles (NDs), and their cytocompatibility with murine neural stem cells. The effects of both nanofiller and protein concentration on the scaffold morphology, aqueous affinity, size modification at rehydration, and degradation are assessed. Our findings indicate that nanostructuring with low amounts of NDs may modify the fiber properties, including a certain regional parallel orientation of fiber segments. NE-4C cells form dense clusters that strongly adhere to the surface of FG50-based scaffolds, while also increasing FG concentration and adding NDs favor cellular infiltration into the flexible fibrous FG70_NDs nanocomposite. This research illustrates the potential of nanostructured NDs-FG fibers as scaffolds for nerve repair and regeneration. We also emphasize the importance of further understanding the effect of the nanofiller-protein interphase on the microstructure and properties of electrospun fibers and on cell-interactivity.

Due to its excellent bone-like mechanical properties and non-toxicity, magnesium (Mg) and its alloys have attracted great interest as biomaterials for orthopaedic applications. However, their fast degradation rate in physiological environments leads to an acute inflammatory response, restricting their use as biodegradable metallic implants. Endowing Mg-based biomaterials with immunomodulatory properties can help trigger a desired immune response capable of supporting a favorable healing process. In this study, electrospun poly(&epsilon, caprolactone) (PCL) fibers loaded with coumarin (CM) and/or zinc oxide nanoparticles (ZnO) were used to coat the commercial AZ31 Mg alloy as single and combined formulas, and their effects on the macrophage inflammatory response and osteoclastogenic process were investigated by indirect contact studies. Likewise, the capacity of the analyzed samples to generate reactive oxygen species (ROS) has been investigated. The data obtained by attenuated total reflection Fourier-transform infrared (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) analyses indicate that AZ31 alloy was perfectly coated with the PCL fibers loaded with CM and ZnO, which had an important influence on tuning the release of the active ingredient. Furthermore, in terms of degradation in phosphate-buffered saline (PBS) solution, the PCL-ZnO- and secondary PCL-CM-ZnO-coated samples exhibited the best corrosion behaviour. The in vitro results showed the PCL-CM-ZnO and, to a lower extent, PCL-ZnO coated sample exhibited the best behaviour in terms of inflammatory response and receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated differentiation of RAW 264.7 macrophages into osteoclasts. Altogether, the results obtained suggest that the coating of Mg alloys with fibrous PCL containing CM and/or ZnO can constitute a feasible strategy for biomedical applications.

This paper presents a new method for the reactive retention of tetracycline from aqueous solutions. For this, cellulose acetate membranes were functionalized with aminopropyl triethoxysilane, followed by reaction of the reaming free amino groups with cyanuric chloride. The reactive retention process is based on passing through the membrane heated feed solution which contains tetracycline. The amino group from tetracycline will react with a chlorine atom from the cyanuric chloride. The synthesized materials were characterized by Scanning Electronic Microscopy, Thermogravimetric Analysis, FT-IR and X-ray Photoelectron Spectroscopy, proving both the material synthesis and also the antibiotic bonding during the separation process. Retention studies were evaluated using UV–Vis Spectroscopy on pre-and post-membrane feed solutions. The water flux with pure water has also been conducted. The modified CA membrane showed an increase of the adsorption capacity from 16% to 88% and an improved permeability from 72 L·m−2·h−1 to 517.66 L·m−2·h−1 compared with pure CA membrane.

The concept of PLGA-lipid hybrid nanoparticles arose as a motivation for developing drug delivery systems with versatile physical and chemical properties, unequivocal therapeutic benefits and minimized side effects. These formulations opened a new avenue of “smart tools” in the development of personalized, noninvasive emerging nanomedicine. However, there is still the risk that smart hybrid system manufactured from a mixture of materials, such as PLGA in combination with synthetic/vegetable lipids and targeting agents might trigger high nanotoxicological responses. This review is focused on the detailed description of PLGA-lipids/oils hybridization concept and its effect on the performances of nanocarriers as powerful, versatile delivery system, the manufacturing methods, the main applications, and their potential clinical impact. The successful design of a hybrid formulation involves two foremost challenges, firstly a comprehensive consideration of essential characteristics of each constituent that form the hybrid system and secondly, a deep understanding of the interactions of hybrid nanocarrier with cells in order to predict the potential toxicity issues and ensure its safe clinical applications.

The assessment of several ink formulations for 3D printing based on two natural macromolecular compounds is presented. In the current research we have exploited the fast crosslinking potential of pectin and the remarkable shear-thinning properties of carboxylated cellulose nanofibrils, which is known to induce a desired viscoelastic behavior. Prior to 3D printing, the viscoelastic properties of the polysaccharide inks were evaluated by rheological measurements and injectability tests. The reliance of the printing parameters on the ink composition was established through one-dimensional lines printing, the base units of 3D-structures. The performance of the 3D-printed structures after ionic cross-linking was evaluated in terms of mechanical properties and rehydration behavior. MicroCT was also used to evaluate the morphology of the 3D-printed objects regarding the effect of pectin/nanocellulose ratio on the geometrical features of scaffolds. The proportionality between the two polymers proved to be the determining factor for the firmness and strength of the printed objects.

Electrocopolymerization of bithiophene with a monomer combining an EDOT moiety with a thiophene ring on which a carboxylic group is attached at the internal β-position via a sulphide linkage (1) has been investigated with the aim of producing a molecularly imprinted polymer. Analysis of the electrochemical behaviour of the film grown under various conditions shows that potentiostatic electrocopolymerization leads to a polymer which can detect ephedrine via an unusual on/off switching of the electrochemical properties of the film in the presence of the target molecule. Keywords: Modified electrodes, Ethylenedioxythiophene, Electropolymerization, Ephedrine

Two new polybenzoxazine products based on a reduced graphene oxide (rGO) were synthesized. The synthesis process started with an rGO with amino functionalities. Benzoxazine structures were synthesized with oxazine rings attached to the surface of rGO and were fully characterized by FT-IR, 1H&ndash, NMR, XPS and XRD. The presence of polybenzoxazine chains was pointed out by 1H&ndash, NMR and it correlated with XRD data which show a partial exfoliation of the graphene oxide layers. The degree of polymerization plays a significant role against the exfoliation process. A higher yield of the ring-opening process for benzoxazine rings leads to a low degree of exfoliation, as the inner covalent bonds within the polybenzoxazine chains keep the graphene oxide sheets together.

The purpose of this work was to more exhaustively study the influence of nanocarrier matrix composition and also the polyethylene glycol (PEG)-modified surface on the performances of formulations as lipophilic drug delivery systems. Poly (d,l-lactide-co-glycolide), two vegetable oils (Nigella sativa oil and Echium oil) and indomethacin were employed to prepare novel PEG-coated nanocarriers through emulsion solvent evaporation method. The surface modification was achieved by physical PEG adsorption (in the post-production step). Transmission electron microscopy (TEM) nanographs highlighted the core-shell structure of hybrid formulations while scanning electron microscopy (SEM) images showed no obvious morphological changes after PEG adsorption. Drug loading (DL) and entrapment efficiency (EE) varied from 4.6% to 16.4% and 28.7% to 61.4%, solely depending on the type of polymeric matrix. The oil dispersion within hybrid matrix determined a more amorphous structure, as was emphasized by differential scanning calorimetry (DSC) investigations. The release studies highlighted the oil effect upon the ability of nanocarrier to discharge in a more sustained manner the encapsulated drug. Among the kinetic models employed, the Weibull and Korsmeyer-Peppas models showed the better fit (R2 = 0.999 and 0.981) with n < 0.43 indicating a Fickian type release pattern. According to cytotoxic assessment the PEG presence on the surface increased the cellular viability with ~1.5 times as compared to uncoated formulations.

The present work aims to develop new biocomposites based on gelatin (Gel) and poly(vinyl alcohol) (PVA) reinforced with graphene oxide (GO). On the one hand, the model is designed with consideration of the high performance of the aforementioned biopolymers as biomaterials; on the other hand, the original component of the system, GO, is expected to improve structural stability and boost mechanical strength. Porous Gel-PVA/GO materials with GO content ranging from 0.5 to 3 wt% are obtained by freeze-drying. Structural analysis by Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed the ability of well-dispersed GO nanosheets to form interactions with the polymers, leading to a unique molecular structuration. 3D analysis by X-ray microtomography (microCT) and scanning electron microscopy (SEM) suggests that GO has an influence on pore adjustment. According to mechanical tests, GO undoubtedly exhibits a beneficial effect on the polymer resistance against compressive stress, improving their compressive strengths by 97-100% with the addition of 0.5-3 wt% GO. Moreover, biological assessment using the MC3T3-E1 preosteoblast murine cell line indicated the fabrication of a cytocompatible composite formula, with potential for further in vivo testing and tissue engineering applications.

Cellulose triacetate (AC)/graphene oxide (GO) porous membranes were successfully fabricated by combining ultrasonication and phase inversion method. The structures and morphologies of the resultant composite membranes were investigated by X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy, respectively. Microscopic and X-ray diffraction measurements revealed that GO sheets were uniformly dispersed within the AC matrix. The pore size and structure were modulated by changing GO concentration from 0.25 to 1 wt%. Membrane thermal properties were also studied. Among all tested membranes, the most favorable GO amount was 1 wt%, giving Td3% of 274°C, which represents a 22°C enhancement compared with AC. Conversely, the membranes showed improved barrier properties against water and ethanol. The decrease of both ethanol and water fluxes was assigned to the stabilization of composite membrane structure, as a result of GO progressive addition. Bovine serum albumin rejection assay indicated an increasing from 78% in the case of CA membrane to 99% in the case of CA/GO 1 wt% of the rejection degree after 90 min. Copyright © 2015 John Wiley & Sons, Ltd.

Porous chitosan/graphene oxide (CHT/GO) biocomposites with 0.5, 1, 2, and 3 wt% GO were prepared by freeze-drying method. The biocomposites were characterized regarding structural, morphological, and thermal properties, degradation, and swelling responses. Raman spectroscopy and scanning electron microscopy (SEM) results indicated good GO dispersion within the polymer host and highly porous structure for the obtained biocomposites. The GO presence has a profound effect on the structural features of the biocomposites generating decrease of swelling degree and enzymatic biodegradation rate. Conversely, the thermal stability of the biocomposites was significantly improved, and the decomposition temperature at which the mass loss is 3% (Td,3%) was increased with 64°C by adding 3 wt% GO within the CHT. The ability of the biocomposites to form apatite-like crystals was also investigated. X-ray diffraction and SEM analyses indicated the formation of apatite deposits on the CHT/GO biocomposites. POLYM. COMPOS., 38:363–370, 2017. © 2015 Society of Plastics Engineers

Technological advances in engineering and cell biology stimulate novel approaches for medical treatment, in particular cell-based therapy. The first cell-based gene therapy against cancer was recently approved by the US Food and Drug Administration. Progress in cancer diagnosis includes a blood test detecting five cancer types. Numerous stem cell phase I/II clinical trials showing safety and efficacy will soon pursue qualifying criteria for advanced therapy medicinal products (ATMP), aspiring to join the first stem-cell therapy approved by the European Medicines Agency. Cell based therapy requires extensive preclinical characterisation of biomarkers indicating mechanisms of action crucial to the desired therapeutic effect. Quantitative analyses monitoring critical functions for the manufacture of optimal cell and tissue-based clinical products include successful potency assays for implementation. The challenge to achieve high quality measurement is increasingly met by progress in biosensor design. We adopt a cell therapy perspective to highlight recent examples of graphene-enhanced biointerfaces for measurement of biomarkers relevant to cancer treatment, diagnosis and tissue regeneration. Graphene based biosensor design problems can thwart their use for health care transformative point of care testing and real-time applications. We discuss concerns to be addressed and emerging solutions for establishing clinical grade biosensors to accelerate human cell therapy.

The development of soft actuators by using inexpensive raw materials and straightforward fabrication techniques, aiming at creating and developing muscle like micromanipulators, represents an important challenge nowadays. Providing such devices with biomimetic qualities, for example, sensing different external stimuli, adds even more complexity to the task. We developed electroactive polymer-coated microribbons that undergo conformational changes in response to external physical and chemical parameters. These were prepared following three simple steps. During the first step nylon-6/6 microribbons were fabricated by electrospinning. In a second step the microribbons were one side coated with a metallic layer. Finally, a conducting layer of polypyrrole was added by means of electrochemical deposition. Strips of polypyrrole-coated aligned microribbon meshes were tested as actuators responding to current, pH, and temperature. The electrochemical activity of the microstructured actuators was investigated by recording cyclic voltammograms. Chronopontentiograms for specific current, pH, and temperature values were obtained in electrolytes with different compositions. It was shown that, upon variation of the external stimulus, the actuator undergoes conformational changes due to the reduction processes of the polypyrrole layer. The ability of the actuator to hold and release thin wires, and to collect polystyrene microspheres from the bottom of the electrochemical cell, was also investigated.

International audience; Nano-apatite and gelatin-alginate hydrogel microparticles have been prepared by a one-step synthesis combined with electrostatic bead generation, for the reconstruction of bone defects. Based on the analysis of bone composition, architecture and embryonic intramembranous ossification, a bio-inspired fabrication has been developed. Accordingly, the mineral phase has been in situ synthesized, calcifying the hydrogel matrix while the latter was crosslinked, finally generating microparticles that can assemble into a bone defect to ensure interconnected pores. Although nano-apatite-biopolymer composites have been widely investigated, microstructural optimization to provide improved distribution and stability of the mineral is rarely achieved. The optimization of the developed method progressively resulted in two types of formulations (15P and 7.5P), with 15 and 7.5 (wt%) phosphate content in the initial precursor. The osteolytic potential was investigated using differentiated macrophages. A commercially available calcium phosphate bone graft substitute (Eurocer 400) was incorporated into the hydrogel, and the obtained composites were in vitro tested for comparison. The cytocompatibility of the microparticles was studied with mouse osteoblast-like cell line MC3T3-E1. Results indicated the best in vitro performance have been obtained for the sample loaded with 7.5P. Preliminary evaluation of biocompatibility into a critical size (3 mm) defect in rabbits showed that 7.5P nanocomposite is associated with newly formed bone in the proximity of the microparticles, after 28 days.

The aim of this study was to address one of the major challenges of the actual era of nanomedicine namely, the bioavailability of poorly water soluble drugs such as Silymarin. We developed new, biodegradable, and biocompatible nanosized shuttles for Silymarin targeted delivery in colon-cancer cells. The design of these 100 nm sized carrier nanoparticles was based on natural polymers and their biological properties such as cellular uptake potential, cytotoxicity and 3D penetrability were tested using a colon cancer cell line (HT-29) as the in vitro culture model. Comparative scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements demonstrated that the Silymarin loaded Poly(3-HydroxyButyrate-co-3-HydroxyValerate) (PHBHV) nanocarriers significantly decreased HT-29 cells viability after 6 and 24 h of treatment. Moreover, in vivo-like toxicity studies on multicellular tumor spheroids showed that the Silymarin loaded PHBHV nanocarriers are able to penetrate 3D micro tumors and significantly reduce their size.

Comparative evaluation of innovative combinations of three types of carbon nanomaterial (CNM) highlighted membranes with important potential for biomedical applications. Non-solvent induced phase separation coupled with ultrasound technique was used to generate membranes comprised of (i) cellulose acetate/ammonia functionalized carbon nanotubes (CA/CNT), (ii) cellulose acetate/ammonia functionalized graphene oxide (CA/GO), and (iii) cellulose acetate/CNT-GO. Structural, topographical and thermal features as well as water and ethanol permeation, bovine serum albumin (BSA) and haemoglobin (Hb) rejection were evaluated. Biocompatibility in terms of cytotoxicity, cell proliferation and adhesion were explored using a 3T3E1 cell line. The formation of amorphous structures, within which the CNMs were well dispersed, facilitated the development of smoother topographies. Addition of CNMs generated morphological changes influencing a decrease in water and ethanol fluxes. Furthermore, CNMs concentrated within the membrane skin layer exhibited repellent effects against BSA and Hb molecules and excellent cytocompatibility.

The main goal of this study was to predict the capacity of the hybrid nanoparticles based on poli (lactic-co-glycolic acid) PLGA-vegetable oil to encapsulate and then to release a bioactive compound. Therefore, the compatibility of different drugs molecules, taking into account the chemical structure, solubility, partition coefficient (log P) with the standard PLGA or hybrid polymer-oil matrix was studied, quantifying the quality of interactions between polymeric matrix and the encapsulated drug using Flory-Huggins theory and computational mesoscopic (MesoDyn) approach. All the drugs-loaded formulations were obtained by emulsion solvent evaporation method. The main parameters such as hydrodynamic characteristics, encapsulation efficiency and release profiles were studied and correlated with the compatibility parameter, drug's partition coefficient and computational mesoscopic simulation. Drugs solubilization, respectively its distribution and loading into a formulation was found to be reliant on the system's compatibility, calculated by the Flory-Huggins interaction parameter (χ), while the drug's partition coefficient has proven to be a key influencer in the drug release kinetics. A consistent correlation of experimental results, computational data and thermodynamic theory was observed for lipophilic drugs, while for more hydrophilic drugs some discrepancy between the experimental/theoretical and computational modelling results was registered.

Graphene research, already prized, is nonetheless challenged to provide material advantages that bring about unique and novel applications rather than simply an improved substitute to existing materials. Arguably driving significant progress are new approaches to its manufacture including combination with other atoms and nanobiocomposite materials that introduce new functional properties. Functionalized graphene can interface with biomolecules to provide new health sector benefits in the form of highly sensitive biosensors that may offer continuous label-free measurement of key bioactive cell molecules, innovative nanoparticles for tissue targeted drug delivery and scaffolds for tissue engineering with previously unachievable qualities favouring tissue integration and biocompatibility. We here describe graphene functionalization methods and provide recent examples of how graphene can be used to achieve biological interactions with innovative outcomes. Above all, these laboratory focused advances each contribute to an incrementally improved understanding of how different forms of graphene and its derivatives can best be tailored to meet biological demands. Much has yet to be discovered with regard to safety profiles and improved manufacture yet considering how carefully derived rational insights might be combined with computational biology to accelerate complex performance models, prospects that graphene-based biomaterials can achieve extraordinary real-world benefits are optimistically poised.

A high number of studies support the use of mesoporous silica nanoparticles (MSN) as carriers for drug delivery systems due to its high biocompatibility both in vitro and in vivo, its large surface area, controlled pore size and, more than this, its good excretion capacity from the body. In this work we attempt to establish the optimal encapsulation parameters of benzalkonium chloride (BZC) into MSN and further study its drug release. The influence of different parameters towards the drug loading in MSN such as pH, contact time and temperature were considered. The adsorption mechanism of the drug has been determined by using the equilibrium data. The modification process was proved using several methods such as Fourier transform-infrared (FT-IR), ultraviolet-visible (UV-VIS), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). Since MSN shows a lower drug release amount due to the agglomeration tendency, in order to increase MSN dispersion and drug release amount from MSN, two common biocompatible and biodegradable polymers were used as polymer matrix in which the MSN-BZC can be dispersed. The drug release profile of the MSN-BZC and of the synthesized hybrid materials were studied both in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Polymer-MSN-BZC hybrid materials exhibit a higher drug release percent than the pure MSN-BZC when a higher dispersion is achieved. The dispersion of MSN into the hybrid materials was pointed out in scanning electron microscope (SEM) images. The release mechanism was determined using four mathematic models including first-order, Higuchi, Korsmeyer&ndash, Peppas and Weibull.