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Lignin is a versatile biomass that possesses many different desirable properties such as antioxidant, antibacterial, anti-UV, and good biocompatibility. Natural lignin can be processed through several chemical processes. The processed lignin can be modified into functionalized lignin through chemical modifications to develop and enhance biomaterials. Thus, lignin is one of the prime candidate for various biomaterial applications such as drug and gene delivery, biosensors, bioimaging, 3D printing, tissue engineering, and dietary supplement additive. This review presents the potential of developing and utilizing lignin in the outlook of new and sustainable biomaterials. Thereafter, we also discuss on the challenges and outlook of utilizing lignin as a biomaterial., Graphical abstract Image 1, Highlights • Lignin's antioxidant, antibacterial, anti-UV and biocompatibility properties can be harnessed. • Modification and functionalization of lignin allows synthesis of enhanced biomaterials. • Biomedical applications of lignin-derived biomaterials include drug and gene delivery, biosensors, and tissue engineering.

A single-input and single-output (SISO) frequency-modulated continuous wave (FMCW) radar architecture is proposed and in vivo demonstrated for remote 2-D localization (range and angular information) and vital signs monitoring of multiple subjects. The radar sensor integrates two frequency scanning antennas which allow angular separation and enable determining a 2-D map (range versus angle) of a room environment from which people can be distinguished from objects and clutter. After technical tests to validate the functionality of the proposed architecture and data processing algorithm, a practical setup was successfully demonstrated to locate human volunteers, at different absolute distances and orientations, and to retrieve their respiratory and heart rate information. Experimental results show that this radar sensor can monitor accurately the vital signs of multiple subjects within typical room settings, reporting maximum mean absolute errors of 0.747 breaths-per-minute and 2.645 beats-per-minute, respectively, for respiration rate and heartbeat. Practical applications arise for Internet of Things (IoT), ambient-assisted living, healthcare, geriatric and quarantine medicine, automotive, rescue and security purposes.

There is an editorial note for this article available under Supplementary Data Abstract The unique size and surface morphology of nanoparticles (NPs) have substantially influenced all aspects of human life, making nanotechnology a novel and promising field for various applications in biomedical sciences. Metallic NPs have gained immense interest over the last few decades due to their promising optical, electrical, and biological properties. However, the aggregation and the toxic nature of these NPs have restricted their utilization in more optimized applications. The optimum selection of biopolymers and biological macromolecules for surface functionalization of metallic NPs will significantly improve their biological applicability and biocompatibility. The present mini-review attempts to stress the overview of recent strategies involved in surface functionalization of metallic NPs, their specific biomedical applications, and comparison of their in vitro, ex vivo, and in vivo toxicities with non-functionalized metallic NPs. In addition, this review also discusses the various challenges for metallic NPs to undergo human clinical trials.

Fine-grained austenitic stainless steels (FGSS) were plasma nitrided below 700 K to describe their microstructure evolution during the nitrogen supersaturation process and to investigate the post-stressing effect on the microstructure and mechanical properties of nitrided FGSS. Normal- and fine-grained AISI304 plates were nitrided at 623 K and 673 K to investigate the grain size effect on the nitrogen supersaturation process as well as the microstructure evolution during the nitriding process. Fine-grained AISI316 (FGSS316) wires were nitrided at 623 K to demonstrate that their outer surfaces were uniformly nitrided to have the same two-phase, refined microstructure with high nitrogen solute content. This nitrided FGSS316 wire had a core structure where the original FGSS316 core matrix was bound by the nitrided FGSS316 layer. The nitrided wire had higher stiffness, ultimate strength, and elongation in the uniaxial tensile testing than its un-nitrided wires. The core microstructure was refined and homogenized by this applied loading together with an increase of nitrided layer hardness.

Marine resources have tremendous potential for developing high-value biomaterials. The last decade has seen an increasing number of biomaterials that originate from marine organisms. This field is rapidly evolving. Marine biomaterials experience several periods of discovery and development ranging from coralline bone graft to polysaccharide-based biomaterials. The latter are represented by chitin and chitosan, marine-derived collagen, and composites of different organisms of marine origin. The diversity of marine natural products, their properties and applications are discussed thoroughly in the present review. These materials are easily available and possess excellent biocompatibility, biodegradability and potent bioactive characteristics. Important applications of marine biomaterials include medical applications, antimicrobial agents, drug delivery agents, anticoagulants, rehabilitation of diseases such as cardiovascular diseases, bone diseases and diabetes, as well as comestible, cosmetic and industrial applications., Graphical abstract Image 1, Highlights • Ocean provides such an abundant of materials that humans have been using marine biomaterials since ancient times. • The efficacy in utilizing these renewable natural resources has been greatly improved because of technological revolution. • Marine organisms possess a plethora of excellent bioactive properties. • The last century has witnessed rapid development in the interdisciplinary utilization of marine biomaterials.

The implementation of nanotechnology to develop efficient antimicrobial systems has a significant impact on the prospects of the biomedical field. Nanogels are soft polymeric particles with an internally cross-linked structure, which behave as hydrogels and can be reversibly hydrated/dehydrated (swollen/shrunken) by the dispersing solvent and external stimuli. Their excellent properties, such as biocompatibility, colloidal stability, high water content, desirable mechanical properties, tunable chemical functionalities, and interior gel-like network for the incorporation of biomolecules, make them fascinating in the field of biological/biomedical applications. In this review, various approaches will be discussed and compared to the newly developed nanogel technology in terms of efficiency and applicability for determining their potential role in combating infections in the biomedical area including implant-associated infections., Graphical abstract Image 1, Highlights • Nanogels are novel soft nanoparticles with high potential impact with the biomedical field. • Nanogels are applied both as bioactive materials in suspension and at interfaces. • Hydrogel nanoparticles have tremendous impact on infection related issues. • Nanogels offer antifouling possibilities and provided controlled release possibilities. • Nanogels can be tuned in their physicochemical properties to match the biomedical application.

The use of 3D digitizing tools is becoming the base for subject-specific products, such as the orthopaedic production process of orthoses and prostheses. This paper aims at comparing the metrological behaviour of low-cost devices (Kinect 1 and 2 by Microsoft, Structure Sensor by Occipital) and high-resolution active sensors (O&P Scan by Rodin4D, NextEngine Ultra HD, Konica Minolta Vivid 9i, GOM ATOS II 400 and Artec Leo) for the survey of human body parts. A calibrated flat plane and a test-field composed of eight calibrated spheres of different radii and placed at different heights were used to evaluate the standard quality parameters (flatness, probing errors in form and size and the standard deviation) for each device as recommended by the VDI/VDE 2634 guidelines. Subsequently, three different parts of a mannequin were surveyed as samples of human body parts. The results demonstrated the higher accuracy of fixed devices with respect to handheld ones, among which Artec Leo and Structure Sensor provided a satisfying level of accuracy for the orthopaedic application. Moreover, the handheld devices enabled performing a fast reconstruction of the mannequin parts in about 20 s, which is acceptable for a person that has to remain as still as possible. For this reason, the Structure Sensor was further tested with five motion approaches which identified that smooth motion provides the lowest deviation and higher reliability. The work demonstrated the appropriateness of handheld devices for the orthopaedic application requirements in terms of speed, accuracy and costs.

Cartilage damage continues to pose a threat to humans, but no treatment is currently available to fully restore cartilage function. In this study, a new class of composite hydrogels derived from water-soluble chitosan (CS)/hyaluronic acid (HA) and silanized-hydroxypropyl methylcellulose (Si-HPMC) (CS/HA/Si-HPMC) has been synthesized and tested as injectable hydrogels for cartilage tissue engineering when combined without the addition of a chemical crosslinking agent. Mechanical studies of CS/HA and CS/HA/Si-HPMC hydrogels showed that as Si-HPMC content increased, swelling rate and rheological properties were higher, compressive strength decreased and degradation was faster. Our results demonstrate that the CS and HA-based hydrogel scaffolds, especially the ones with 3.0% (w/v) Si-HPMC and 2.5/4.0% (w/v) CS/HA, have suitable physical performance and bioactive properties, thus provide a potential opportunity to be used for cartilage tissue engineering. In vitro studies of CS/HA and CS/HA/Si-HPMC hydrogels encapsulated in chondrocytes have shown that the proper amount of Si-HPMC increases the proliferation and deposition of the cartilage extracellular matrix. The regeneration rate of the CS/HA/Si-HPMC (3%) hydrogel reached about 79.5% at 21 days for long retention periods, indicating relatively good in vivo bone regeneration. These CS/HA/Si-HPMC hydrogels are promising candidates for tissue compatibility injectable scaffolds. The data provide proof of the principle that the resulting hydrogel has an excellent ability to repair joint cartilage using a tissue-engineered approach.RESEARCH HIGHLIGHTSAn injectable hydrogel based on CS/HA/Si-HPMC composites was developed.The CS/HA/Si-HPMC hydrogel displays the tunable rheological with mechanical properties.The CS/HA/Si-HPMC hydrogel is highly porous with high swelling and degradation ratio.Increasing concentration of Si-HPMC promote an organized network in CS/HA/Si-HPMC hydrogels.Injectable CS/HA/Si-HPMC hydrogels have a high potential for cartilage tissue engineering., Graphical Abstract

The surface texturing of ceramics is generally performed through acid-based etching and machining; however, laser texturing may be considered as a more precise, reproducible and eco-friendly process. Furthermore, laser ablation may be used to produce complex patterns on ceramic surfaces, thus offering new surface engineering opportunities. The studies so far conducted on this topic have mainly been application-driven, and since a wide variety of lasers have been used for surface texturing, it is difficult to have a comprehensive understanding of this technique applied to ceramics and ceramic composite materials. Laser texturing requires a great deal of knowledge of the material and the laser source parameters to optimise the process in order to obtain the expected results. It is therefore important to expand the research on the laser texturing of ceramics and CMCs in order to build a relevant amount of literature that can be used to identify the most appropriate parameters for each application. This review provides an overview of most of the technological aspects considered relevant for the laser surface texturing of ceramics and CMCs, and includes the fundamentals of laser-material interactions and a summary of the used equipment and parameters. Furthermore, most of the techniques related to the modifications of surface material induced by a laser are critically reviewed, and the new horizons that are opening up, in the context of the modification of surfaces to improve the performances of materials for several applications, are discussed.

Heating at the nanoscale is the basis of several biomedical applications, including magnetic hyperthermia therapies and heat-triggered drug delivery. The combination of multiple inorganic materials in hybrid magnetic nanoparticles provides versatile platforms to achieve an efficient heat delivery upon different external stimuli or to get an optical feedback during the process. However, the successful design and application of these nanomaterials usually require intricate synthesis routes and their magnetic response is still not fully understood. In this review we give an overview of the novel systems reported in the last few years, which have been mostly obtained by organic phase-based synthesis and epitaxial growth processes. Since the heating efficiency of hybrid magnetic nanoparticles often relies on the exchange-interaction between their components, we discuss various interface-phenomena that are responsible for their magnetic properties. Finally, followed by a brief comment on future directions in the field, we outline recent advances on multifunctional nanoparticles that can boost the heating power with light and combine heating and temperature sensing in a single nanomaterial., Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

Natural bioflavonoids are an essential component of dietary supplements possessing antimicrobial properties. Many of the bioflavonoids have resulted in positive antitumor, anticancer, antibacterial, antifungal, anti-inflammatory properties, but the efficacy remains low due to toxicity at the molecular level whereas antiviral property limits to negative. The synergistic link between nanoscience and flavonoid chemistry enhances the epidemiological properties of flavonoid and also diminish the antimicrobial resistivity (AMR) by forming their hybrid nanocomposites. Nanochemistry uses various nanocomposite and nanomaterials for biosensing the flavonoids and their delivery as a drug. The quercetin flavonoid and its derivatives such as rutin, and myricetin are used for sensing and drug delivery. Quercetin with 15Carbon-5Hydroxyl chemical scaffold has been explored for a few decades for the development of hybrid nanocomposite and nanomaterial with metallic as well as organic nano co-composites. This quercetin flavonoid based hybrid nanocomposites seemed to show a significant effect on In vitro and some animal model processes along with attenuating lipid peroxidation, platelet aggregation, and capillary permeability actions. This review mainly focused on the hybrid nanoscience of quercetin bioflavonoid and its application in numerous biological, material fields with a future perspective.

Composite cements based on alpha-tricalcium phosphate (alpha-TCP) and nanostructured fluorapatite (FAp), alpha-TCP/FAp, appropriate for dental usage as root canal filling material, have been prepared with the improved mechanical properties and biocompatibility. The influence of FAp concentration on the composite cement properties was investigated. The processing conditions for FAp powders synthesis were optimized and the powder with optimal properties was chosen to obtain alpha-TCP/FAp composite types of cement alpha-TCP powder was prepared by calcination of hydrothermally synthesized hydroxyapatite (HAp) at 1500 degrees C for 2 h. Morphology and phase composition of powders were investigated by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS). Soaking of alpha-TCP/FAp specimens in simulated body fluid (SBF) affected the successful transformation of alpha-TCP into HAp, while the compressive test revealed the influence of this transformation and FAp content on the mechanical properties of the composites. Specimen containing 5% of FAp after 10 days in SBF showed the highest compressive strength. In vitro MIT and DET biocompatibility tests, performed in the culture of MRC-5 human fibroblast cells, revealed that alpha-TCP/FAp had no cytotoxic effect. These initial findings showed that alpha-TCP/FAp composite cements could yield favorable mechanical properties with no adverse effect on biocompatibility.

The present study concerned with the use of an aqueous ginger extract as naturally and eco-friendly reducing and stabilizing agent in the synthesis of silver nanoparticles (AgNPs). The unique physicochemical characteristics of green synthesized AgNPs exhibit high potential antimicrobial activity and displayed an impact role in pharmaceutical determinations. To confirm the nanoscale of green synthesized AgNPs, various microscopic and spectroscopic techniques were performed. The synthesized nanoparticles were screened for their antimicrobial activity against several strains of bacteria and fungi. The obtained results showed excellent bactericidal and fungicidal effects. Also, the spectrofluorimetric analysis of anastrozole drug in bulk powder and dosage form was investigated. The suggested method displayed linear relationship between the drug concentrations and the fluorescence intensity between 2 and 100 µgmL−1 with regression equation was IFL = 9.1917C+ 65.945, n = 10 and r = 0.9995 at λex 390 and λem 440 nm. The green synthesized AgNPs using ginger extract demonstrated a potential activity in pharmaceutical and biomedical fields.

Keratin constitutes the major component of the feather, hair, hooves, horns, and wool represents a group of biological material having high cysteine content (7–13%) as compared to other structural proteins. Keratin -based biomaterials have been investigated extensively over the past few decades due to their intrinsic biological properties and excellent biocompatibility. Unlike other natural polymers such as starch, collagen, chitosan, the complex three-dimensional structure of keratin requires the use of harsh chemical conditions for their dissolution and extraction. The most commonly used methods for keratin extraction are oxidation, reduction, steam explosion, microbial method, microwave irradiation and use of ionic liquids. Keratin -based materials have been used extensively for various biomedical applications such as drug delivery, wound healing, tissue engineering. This review covers the structure, properties, history of keratin research, methods of extraction and some recent advancements related to the use of keratin derived biomaterials in the form of a 3-D scaffold, films, fibers, and hydrogels., Graphical abstract Image 1, Highlights • Keratin a versatile material having unique structural moiety. • Keratin sources and methods of extraction. • Keratin-based materials for biomedical applications. • 3-D scaffold, films, fibers, and hydrogels.

Strontium (Sr) ions are known for its role on increasing bone mineral density. However, a high dosage through mouth may cause many side effects. An alternative to provide a low but steady release at the location of bone defect is therefore explored. In the present study, various amounts of strontium sulfate (SrSO4) were dissolved into calcium sulfate (CaSO4) at elevated temperatures. The release of Sr ions from the (Ca,Sr)SO4 solid solution into various aqueous solutions was then measured. Through the control of Sr content in (Ca,Sr)SO4, the Sr amount releasing into the aqueous solutions could be tailored. After implanting a solid solution into distal femur in rat, a low release of Sr into blood was confirmed.

In recent ten years, 3D printing technology has been developed rapidly. As an advanced technology, 3D printing has been used to fabricate complex and high-precision objects in many fields. 3D printing has several technologies. Among these technologies, photo-curing 3D printing was the earliest and most mature technology. In 1988, the first 3D printing machine which was based on photo-curing and called Stereo lithography Appearance (SLA) technology was produced by 3D system Corp. After 30 years of development, many new technologies based on photocuring mechanism emerged. Based on the different principle of pattern formation and character of printing technology, numerous photocuring 3D printing techniques, such as SLA, DLP, LCD, CLIP, MJP, two-photon 3D printing, holographic 3D printing and so on, have been developed. Photo-curing 3D printing has many advantages, such as high precision, smooth surface of printing objects, rapid printing speed and so on. Here, we would introduce five industrial photocuring 3D printing technologies, which are SLA, DLP, LCD, CLIP and MJP. The characters of the materials and the progress of the application of the technique in the biomedical field is also overviewed. At last, the difficulties and challenges of photo-curing 3D printing are also discussed., Highlights • Different techniques of photocuring 3D printing were overviewed. • The advantage, disadvantage and application of the different techniques of photocuring 3D printing were discussed. • The progress of photocuring 3D printing technique in biomedical application is commented. • The existing problems and challenges of photocuring 3D printing were presented.

Current Fused Deposition Modelling (FDM) techniques have promoted the extension of 3D printing technologies to new applications ranging from the biomedical, aerospace, and submarine fields, to some specific applications in manufacturing and civil fields. The expansion of the fields of application, generally, entails considering peculiar characteristics, such as complex geometries or requirements as low density. Furthermore, the breathability, the pleasantness to the touch, aesthetic appearance and a strong visual identity, that can be achieved by means of 3D printing, are especially requested for some applications such as biomedical. For the improvement of the manufacturing of these parts, the design of a dedicated filament is a relevant issue to be taken into account. polylactic acid (PLA) and organic by-products from agricultural waste. The study includes a preliminary illustration of the main properties of these materials and a biomedical application of such bio-plastic compounds through experimental testing in order to assess the suitability to FDM printing. In particular, the performance in terms of lightweight, strength and roughness have been evaluated. The interesting final properties make these materials suitable for biomedical applications as it is shown in this study for the neck collar prototype reported. In addition, such innovative bio-composite materials allow reducing the cost of environmental impact as well as the production management costs.

Micro/nano-fabrication technology via two-photon polymerization (TPP) nanolithography is a powerful and useful manufacturing tool that is capable of generating two dimensional (2D) to three dimensional (3D) arbitrary micro/nano-structures of various materials with a high spatial resolution. This technology has received tremendous interest in cell and tissue engineering and medical microdevices because of its remarkable fabrication capability for sophisticated structures from macro- to nano-scale, which are difficult to be achieved by traditional methods with limited microarchitecture controllability. To fabricate precisely designed 3D micro/nano-structures for biomedical applications via TPP nanolithography, the use of photoinitiators (PIs) and photoresists needs to be considered comprehensively and systematically. In this review, widely used commercially available PIs are first discussed, followed by elucidating synthesis strategies of water-soluble initiators for biomedical applications. In addition to the conventional photoresists, the distinctive properties of customized stimulus-responsive photoresists are discussed. Finally, current limitations and challenges in the material and fabrication aspects and an outlook for future prospects of TPP for biomedical applications based on different biocompatible photosensitive composites are discussed comprehensively. In all, this review provides a basic understanding of TPP technology and important roles of PIs and photoresists for fabricating high-precision stimulus-responsive micro/nano-structures for a wide range of biomedical applications.

The use of electromagnetic fields applied to human tissues has proven to be beneficial in several applications, such as monitoring physiological parameters and delivering medical treatments. Often applications rely on targeted energy deposition into the tissue, or rely on wireless powering of implanted devices. In such cases, the system energy efficiency, the stability of the field, and ultimately the process safety could all benefit from minimizing the mismatch at the air-skin interface. In this article, the maximization of the electric field transmitted into the muscle tissue is initially addressed by optimizing a dielectric-only matching layer in terms of thickness and relative dielectric permittivity, and under realistic constraints on low-cost available materials. The propagation of the electromagnetic field inside a multilayered medium that represents the body is evaluated by using the wave-transmission chain matrix approach. Furthermore, an innovative solution, based on the application of a metasurface matching layer (MML), is proposed to significantly improve the performance of the matching, thus enhancing the electromagnetic fields reaching the targeted muscle tissue. A thorough assessment of the performance is carried out considering both the presence of an air gap, and the case of plane waves impinging at oblique incidence.

The development of novel magnetic nanoparticles (MNPs) with satisfactory biocompatibility for biomedical applications has been the subject of extensive exploration over the past two decades. In this work, we synthesized superparamagnetic iron oxide MNPs coated with polystyrene sulfonic acid (PSS-MNPs) and with a conventional co-precipitation method. The core size and hydrodynamic diameter of the PSS-MNPs were determined as 8–18 nm and 50–200 nm with a transmission electron microscopy and dynamic light scattering, respectively. The saturation magnetization of the particles was measured as 60 emu g−1 with a superconducting quantum-interference-device magnetometer. The PSS content in the PSS-MNPs was 17% of the entire PSS-MNPs according to thermogravimetric analysis. Fourier-transform infrared spectra were recorded to detect the presence of SO3− groups, which confirmed a successful PSS coating. The structural properties of the PSS-MNPs, including the crystalline lattice, composition and phases, were characterized with an X-ray powder diffractometer and 3D nanometer-scale Raman microspectrometer. MTT assay and Prussian-blue staining showed that, although PSS-MNPs caused no cytotoxicity in both NIH-3T3 mouse fibroblasts and SK-HEP1 human liver-cancer cells up to 1000 μg mL−1, SK-HEP1 cells exhibited significantly greater uptake of PSS-MNPs than NIH-3T3 cells. The low cytotoxicity and high biocompatibility of PSS-MNPs in human cancer cells demonstrated in the present work might have prospective applications for drug delivery., GRAPHICAL ABSTRACT

Aluminum-silicate cenospheres are the most valuable residue present in fly ashes after combusting stone coal. Cenospheres are hollow bodies with desirable engineering properties, such as hardness, low bulk density and complete chemical inertness, thanks to which they can be used in biomedical engineering. The following review presents data on obtaining and processing the material, as well as potential biomedical applications.

Drug carriers with intelligent functions are powerful therapeutic and diagnostic platforms in curing various diseases such as malignant neoplasms. These functions include the remote noninvasive activation of drug using physical impacts, e.g. light exposure. Combination of different therapeutic modalities (chemotherapy, photodynamic therapy, and so forth) with light-responsive carriers enables promising synergetic effect in tumour treatment. The main goal of this review article is to provide the state of the art on light-sensitive delivery systems with the identification of future directions and their implementation in tumour treatment. In particular, this article reviews the general information on the physical and chemical fundamental mechanisms of interaction between light and carrier systems (e.g. plasmonic and dielectric nanoparticles), the design of optically responsive drug carriers (plain and composite), and the mechanisms of light-driven controlled release of bioactive compounds in biological environment. The special focus is dedicated to the most recent advances in optically responsive bioinspired drug vehicles.

Precisely engineered magnetic nanoparticles (MNPs) have been widely explored for applications including theragnostic platforms, drug delivery systems, biomaterial/device coatings, tissue engineering scaffolds, performance-enhanced therapeutic alternatives and even in SARS-CoV-2 detection strips. Such popularity is due to their unique, challenging, and tailorable physicochemical/magnetic properties. Given the wide biomedical-related potential applications of MNPs, significant achievements have been reached and published (exponentially) in the last five years, both in synthesis and application tailoring. Within this review, and in addition to essential works in this field, we have focused on the latest representative reports regarding the biomedical use of MNPs, including characteristics related to their oriented synthesis, tailored geometry, and designed multibio-functionality. Further, actual trends, needs and limitations of magnetic-based nanostructures for biomedical applications will be also discussed., The authors thank the FCT, Fundaccommaa~o para a Ciencia e Tecnologia, for financial support in the framework of the Strategic Funding UID/FIS/04650/2020 and under projects PTDC/BTM-MAT/28237/2017 and PTDC/EMD-EMD/28159/2017. P.M., P.M.M., A.C.L., and S.R. also acknowledge support from FCT for the contract under the Stimulus of Scientific Employment, Individual Support -CEECIND/03975/2017 and CEECIND/02802/2020, and for the SFRH/BD/132624/2017, UMINHO/BI/316/2019 grants, respectively. Finally, the authors acknowledge funding by the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019106099RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry and Education Department under the ELKARTEK, HAZITEK, and PIBA (PIBA-201806) programs, respectively.

International audience; For the first time, the sol-gel method was coupled with electrostatic spray deposition (ESD) to fabricate nanotextured bioactive glass (BG) coatings with a controlled microstructure in a one-pot-process. Three BG compositions belonging to the SiO2-CaO-P2O5 system (S85, S75, and S58) were homogeneously deposited on metallic Ti6Al4V substrates starting from the atomization of precursor solutions. All coatings displayed an amorphous character, as confirmed by XRD. A wide variety of innovative BG morphologies were obtained, tuning the key parameters of ESD, leading from highly porous coral-like to compact reticular-type coatings. The bioactivity, in terms of apatite formation, of as-deposited coatings was tested by immersion in simulated body fluid solution. Textural properties were found to play an important impact in its biological performance. Highly porous ESD-coatings exhibited remarkable bioactivity for S75 and S58 compositions, compared with more compacted ones of equal formulations. S85 composition was found extremely reactive regardless of the coating microstructure.

Additive manufacturing techniques established a new paradigm in the manufacture of composite materials providing a simple solution to build complex, custom designed shapes. In the biomedical field, 3D printing enabled the production of scaffolds with patient-specific requirements, controlling product architecture and microstructure, and have been proposed to regenerate a variety of tissues such as bone, cartilage, or the nervous system. Polymers reinforced with graphene or graphene derivatives have demonstrated potential interest for applications that require electrical and mechanical properties as well as enhanced cell response, presenting increasing interest for applications in the biomedical field. The present review focuses on graphene-based polymer nanocomposites developed for additive manufacturing fabrication, provides an overview of the manufacturing techniques available to reach the different biomedical applications, and summarizes relevant results obtained with 3D printed graphene/polymer scaffolds and biosensors., PC acknowledges the support of the Portuguese Foundation for Science and Technology (FCT) through the National Funds Reference UIDB/05256/ 2020 and UIDP/05256/2020. I3Bs acknowledges the support of FCT through the Project SeaJellyBone (PTDC/BTM-MAT/28123/2017). MS acknowledges FCT for the PhD Grant Reference SFRH/BD/138244/2018

Ionic liquids (ILs) have been extensively explored and implemented in different areas, ranging from sensors and actuators to the biomedical field. The increasing attention devoted to ILs centers on their unique properties and possible combination of different cations and anions, allowing the development of materials with specific functionalities and requirements for applications. Particularly for biomedical applications, ILs have been used for biomaterials preparation, improving dissolution and processability, and have been combined with natural and synthetic polymer matrixes to develop IL-polymer hybrid materials to be employed in different fields of the biomedical area. This review focus on recent advances concerning the role of ILs in the development of biomaterials and their combination with natural and synthetic polymers for different biomedical areas, including drug delivery, cancer therapy, tissue engineering, antimicrobial and antifungal agents, and biosensing., The authors thank the FCT (Fundacao para a Ciencia e Tecnologia) for financial support under the framework of the Strategic Funding UID/FIS/04650/2019 and pro-jects PTDC/BTM-MAT/28237/2017, PTDC/EMD-EMD/28159/2017, and PTDC/FIS-MAC/28157/2017. Funds provided by FCT in the framework of EuroNano-Med 2016 call, Project LungChek ENMed/0049/2016 are also gratefully acknowledged. D.M.C., L.C.F., R.M.M., and M.M.F. also thank the FCT for the grants SFRH/BPD/121526/2016, SFRH/BD/145345/2019, and FRH/BD/148655/2019, SFRH/BPD/121464/2016, respectively and CR thanks the FCT for the contract under the Stimulus of Scientific Employment (2020.04163.CEECIND). S.L.M. and J.R. acknowledge the funding support from the Spanish State Research Agency (AEI) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry Department under the ELKARTEK program., info:eu-repo/semantics/publishedVersion

International audience; There is a challenging need for the development of new alternative nanostructures that can allow the coupling and/or encapsulation of therapeutic/diagnostic molecules while reducing their toxicity and improving their circulation and in-vivo targeting. Among the new materials using natural building blocks, peptides have attracted significant interest because of their simple structure, relative chemical and physical stability, diversity of sequences and forms, their easy functionalization with (bio)molecules and the possibility of synthesizing them in large quantities. A number of them have the ability to self-assemble into nanotubes, -spheres, -vesicles or -rods under mild conditions, which opens up new applications in biology and nanomedicine due to their intrinsic biocompatibility and biodegradability as well as their surface chemical reactivity via amino- and carboxyl groups. In order to obtain nanostructures suitable for biomedical applications, the structure, size, shape and surface chemistry of these nanoplatforms must be optimized. These properties depend directly on the nature and sequence of the amino acids that constitute them. It is therefore essential to control the order in which the amino acids are introduced during the synthesis of short peptide chains and to evaluate their in-vitro and in-vivo physico-chemical properties before testing them for biomedical applications. This review therefore focuses on the synthesis, functionalization and characterization of peptide sequences that can self-assemble to form nanostructures. The synthesis in batch or with new continuous flow and microflow techniques will be described and compared in terms of amino acids sequence, purification processes, functionalization or encapsulation of targeting ligands, imaging probes as well as therapeutic molecules. Their chemical and biological characterization will be presented to evaluate their purity, toxicity, biocompatibility and biodistribution, and some therapeutic properties in vitro and in vivo. Finally, their main applications in the biomedical field will be presented so as to highlight their importance and advantages over classical nanostructures.

Due to their outstanding properties, carbon-based structures have received much attention from the scientific community. Their applications are diverse and include use in coatings on self-lubricating systems for anti-wear situations, thin films deposited on prosthetic elements, catalysis structures, or water remediation devices. From these applications, the ones that require the most careful testing and improvement are biomedical applications. The biocompatibility and antibacterial issues of medical devices remain a concern, as several prostheses still fail after several years of implantation and biofilm formation remains a real risk to the success of a device. Sputtered deposition prevents the introduction of hazardous chemical elements during the preparation of coatings, and this technique is environmentally friendly. In addition, the mechanical properties of C-based coatings are remarkable. In this paper, the latest advances in sputtering methods and biocompatibility and antibacterial action for diamond-based carbon (DLC)-based coatings are reviewed and the greater outlook is then discussed., This research is sponsored by national funds through FCT—Fundação para a Ciência e a Tecnologia, under the projects UIDB/00285/2020, UID/EMS/00285/2019 and UIDB/04650/2020, ATRITO-0 (co-financed via FEDER (PT2020) POCI-01-545 0145-FEDER-030446) and On-SURF (cofinanced via FEDER (PT2020) POCI-01-0247-FEDER-024521). Also, this work is supported by European Regional Development Fund (ERDF), through the Centro 2020 Regional Operational Programme under project CENTRO-01-0145-FEDER-000012-HealthyAging2020, and through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization and Portuguese national funds via FCT-Fundação para a Ciência e a Tecnologia, under projects POCI-01-0145-FEDER-007440 and UID/NEU/04539/2019.

The use of biomaterials and scaffolds to boost bone regeneration is increasingly gaining interest as a complementary method to the standard surgical and pharmacological treatments in case of severe injuries and pathological conditions. In this frame, the selection of biomaterials and the accurate assessment of the manufacturing procedures are considered key factors in the design of constructs able to resemble the features of the native tissue and effectively induce specific cell responses. Accordingly, composite scaffolds based on type-I-collagen can mimic the composition of bone extracellular matrix (ECM), while electrospinning technologies can be exploited to produce nanofibrous matrices to resemble its architectural organization. However, the combination of collagen and electrospinning reported several complications due to the frequent denaturation of the protein and the variability of results according to collagen origin, concentration, and solvent. In this context, the strategies optimized in this study enabled the preparation of collagen-based electrospun scaffolds characterized by about 100 nm fibers, preserving the physico-chemical properties of the protein thanks to the use of an acetic acid-based solvent. Moreover, nanoparticles of mesoporous bioactive glasses were combined with the optimized collagen formulation, proving the successful design of composite scaffolds resembling the morphological features of bone ECM at the nanoscale.

MgCa and MgGd series of alloys are often reported as promising candidates for biomedical applications. In the present study, cytotoxicity and corrosion behavior of Mg1Ca and Mg10Gd alloys in different electrolytes (NaCl, PBS, MEM) have been investigated in order to make a direct comparison and understand the mechanisms behind their performance. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were employed to analyze corrosion processes depending on media composition, whereas X-Ray diffraction (XRD) and scanning electron microscopy (SEM) were used to evaluate crystalline structure, phase composition and surface morphology of the corroded substrates after immersion in the different electrolytes. Moreover, cytotoxicity of the Mg alloys was assessed using the WST-1 reduction and lactate dehydrogenase (LDH) release assays in L929 mouse fibroblasts. The electrochemical results showed that Mg1Ca has a lower degradation rate when compared to Mg10Gd, due to the lower microgalvanic effects and the presence of Ca as an alloying element. Furthermore, the corrosion activity is reduced in MEM, for both alloys, when compared to NaCl and PBS. The cytotoxicity assays revealed that Mg10Gd was cytotoxic in all the conditions tested, while the toxicity of Mg1Ca was low. Overall, these findings show that Mg1Ca alloy presents a higher corrosion resistance and biocompatibility and is a promising material to be used in biomedical implants. This work was financed by Portugal 2020 through European Regional Development Fund (ERDF) in the frame of Operational Competitiveness and Internationalization Programme (POCI), in the scope of the project MAGICOAT POCI-01-0145-FEDER-016597/PTDC/CTM-BIO/2170/2014 and in the scope of the project CICECO - Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. Furthermore, thanks are due to Portuguese Foundation for Science and Technology/MCTES for the financial support through national funds to EPI Unit (info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB/04750/2020/PT).

A new configuration of a pseudo-correlation type radiometer is proposed for a microwave biomedical application, such as diabetic foot neuropathy. The new approach as well as its simulated performance are thoroughly assessed using commercial off-the-shelf components and custom designed subsystems. We configured a pseudo-correlation receiver, centred at 3.5 GHz, to validate the proposal, comparing its simulated response with a measured alternative based on a 90∘ hybrid coupler pseudo-correlation prototype. We custom designed a balanced Wilkinson power divider and a 180∘ hybrid coupler to fulfil the receiver’s requirements. The proposed configuration demonstrated an improved noise temperature response. The main advantage is to enable the recalibration of the receiver through simultaneous measurable output signals, proportional to each input signal, as well as the correlated response between them.

Optoacoustic imaging is a hybrid biomedical imaging modality which collects ultrasound waves generated via photoexciting contrast agents in tissues and produces images of high resolution and penetration depth. As a functional optoacoustic imaging technique, multispectral optoacoustic imaging, which can discriminate optoacoustic signals from different contrast agents by illuminating samples with multi-wavelength lasers and then processing the collected data with specific algorithms, assists in the identification of a specific contrast agent in target tissues and enables simultaneous molecular and physiological imaging. Moreover, multispectral optoacoustic imaging can also generate threedimensional images for biological tissues/samples with high resolution and thus holds great potential in biomedical applications. Contrast agents play essential roles in optoacoustic imaging, and they have been widely explored and applied as probes and sensors in recent years, leading to the emergence of a variety of new contrast agents. In this review, we aim to summarize the latest advances in emerging contrast agents, especially the activatable ones which can respond to specific biological stimuli, as well as their preclinical and clinical applications. We highlight their design strategies, discuss the challenges and prospects in multispectral optoacoustic imaging, and outline the possibility of applying it in clinical translation and public health services using synthetic contrast agents. Agency for Science, Technology and Research (A*STAR) National Research Foundation (NRF) Submitted/Accepted version This work was supported by the National Natural Science Foundation of China (21788102), the Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates (2019B030301003), the Singapore Agency for Science, Technology and Research (A*STAR) AME IRG grant (A20E5c0081), and the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03).

The polyol method has been used to synthesize CoNiFe and CoNiZn alloy nanoparticles (NPs). The magnetic characteristics of the products have been measured by vibration sample magnetometry (VSM) analysis. At the same time, the microstructure and morphology were inspected by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Magnetic measurement of samples by the VSM indicated that samples have soft ferromagnetic behavior. Spherical-shaped grains for samples were confirmed by the SEM. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and lactate dehydrogenase (LDH) assays were used to determine the cytotoxic effects of the synthesized NPs. Cytotoxic evaluations showed that treatment with 25 to 400 µg/mL of CoNiZn and CoNiFe NPs exerted a significant time- and concentration-dependent toxicity in MCF7 and HUVEC cells and markedly enhanced the LDH leakage after 48 h of exposure (p &lt, 0.05 compared with untreated cells). Furthermore, NPs with concentrations higher than 12.5 µg/mL induced evident morphological changes in the studied cell lines. Treatment with 12.5 µg/mL of CoNiZn and CoNiFe NPs was safe and did not affect normal human cell survival. The results of in vitro cytotoxicity assessments show promise in supporting the suitability of the synthesized NPs to build high-performance theranostic nanoplatforms for simultaneous cancer imaging and therapy without affecting normal human cells.

Neighboring carbon and sandwiched between non‐metals and metals in the periodic table of the elements, boron is one of the most chemically and physically versatile elements, and can be manipulated to form dimensionally low planar structures (borophene) with intriguing properties. Herein, the theoretical research and experimental developments in the synthesis of borophene, as well as its excellent properties and application in many fields, are reviewed. The decade‐long effort toward understanding the size‐dependent structures of boron clusters and the theory‐directed synthesis of borophene, including bottom‐up approaches based on different foundations, as well as up‐down approaches with different exfoliation modes, and the key factors influencing the synthetic effects, are comprehensively summarized. Owing to its excellent chemical, electronic, mechanical, and thermal properties, borophene has shown great promise in supercapacitor, battery, hydrogen‐storage, and biomedical applications. Furthermore, borophene nanoplatforms used in various biomedical applications, such as bioimaging, drug delivery, and photonic therapy, are highlighted. Finally, research progress, challenges, and perspectives for the future development of borophene in large‐scale production and other prospective applications are discussed., The successful theoretical‐research‐guided synthesis of borophene marks a milestone for the synthesis of 2D materials without layered bulk structures. The excellent properties and wide applications of borophene make it a new cousin of graphene in the family of 2D materials.

Transient technology seeks the development of materials, devices, or systems that undergo controlled degradation processes after a stable operation period, leaving behind harmless residues. To enable externally powered fully transient devices operating for longer periods compared to passive devices, transient batteries are needed. Albeit transient batteries are initially intended for biomedical applications, they represent an effective solution to circumvent the current contaminant leakage into the environment. Transient technology enables a more efficient recycling as it enhances material retrieval rates, limiting both human and environmental exposures to the hazardous pollutants present in conventional batteries. Little efforts are focused to catalog and understand the degradation characteristics of transient batteries. As the energy field is a property-driven science, not only electrochemical performance but also their degradation behavior plays a pivotal role in defining the specific end-use applications. The state-of-the-art transient batteries are critically reviewed with special emphasis on the degradation mechanisms, transiency time, and biocompatibility of the released degradation products. The potential of transient batteries to change the current paradigm that considers batteries as harmful waste is highlighted. Overall, transient batteries are ready for takeoff and hold a promising future to be a frontrunner in the uptake of circular economy concepts., Advanced Science, 8 (12), ISSN:2198-3844

Nano-based particles synthesized via green routes have a particular structure that is useful in biomedical applications as they provide cheap, eco-friendly, and non-toxic nanoparticles. In the present study, we reported the effect of various concentrations of Zinc oxide nanoparticles synthesized using A. lebbeck stem bark extract (ZnO NPsAL) as stabilizing agent on rat biochemical profiles and tissue morphology. Adult Wistar rats weighing 170 ± 5 g were randomly classified into eight groups of five rats each, Group A served as a control fed with normal diet and water. Groups B1, B2, C1, C2, D1, D2, and E were treated with 40 mg/kg and 80 mg/kg of the 0.01, 0.05, and 0.1 M biosynthesized ZnO NPsAL and zinc nitrate daily by the gavage method, respectively. The rats were anesthetized 24 h after the last treatment, blood samples, kidney, heart, and liver tissues were collected for biochemical and histopathological analysis. The rats mean body weight, serum alkaline phosphatase, alanine aminotransferase, creatinine, urea, bilirubin, protein, albumin, globulin, total cholesterol, triacylglycerol, and high-density lipoprotein were significantly altered with an increased concentration of biosynthesized ZnO NPsAL when compared with the control group (p &lt, 0.05, n ≥ 5). Furthermore, histopathological analysis of treated rats’ kidney, heart, and liver tissue revealed vascular congestion, tubular necrosis, inflammation, and cytoplasmic vacuolation. Biosynthesized ZnO NPsAL showed significant alteration in biochemical parameters and tissue morphology in rats with increasing concentrations of the nanoparticles.

Of the multiple areas of applications of DNA nanotechnology, stimuli-responsive nanodevices have emerged as an elite branch of research owing to the advantages of molecular programmability of DNA structures and stimuli-responsiveness of motifs and DNA itself. These classes of devices present multiples areas to explore for basic and applied science using dynamic DNA nanotechnology. Herein, we take the stake in the recent progress of this fast-growing sub-area of DNA nanotechnology. We discuss different stimuli, motifs, scaffolds, and mechanisms of stimuli-responsive behaviours of DNA nanodevices with appropriate examples. Similarly, we present a multitude of biological applications that have been explored using DNA nanodevices, such as biosensing, in vivo pH-mapping, drug delivery, and therapy. We conclude by discussing the challenges and opportunities as well as future prospects of this emerging research area within DNA nanotechnology.

Bio-photonic devices that utilize the interaction between light and biological substances have been emerging as an important tool for clinical diagnosis and/or therapy. At the same time, implanted biodegradable photonic devices can be disintegrated and resorbed after a predefined operational period, thus avoiding the risk and cost associated with the secondary surgical extraction. In this paper, the recent progress on biodegradable photonics is reviewed, with a focus on material strategies, device architectures and their biomedical applications. We begin with a brief introduction of biodegradable photonics, followed by the material strategies for constructing biodegradable photonic devices. Then, various types of biodegradable photonic devices with different functionalities are described. After that, several demonstration examples for applications in intracranial pressure monitoring, biochemical sensing and drug delivery are presented, revealing the great potential of biodegradable photonics in the monitoring of human health status and the treatment of human diseases. We then conclude with the summary of this field, as well as current challenges and possible future directions.

Hydroxyapatite (HAp) is a bioceramic widely studied due to its chemical similarity with the mineral component of bones. Besides, it is biocompatible, bioactive and thermodynamically stable in the body fluid what poses it as an attractive material for a wide range of applications in the biomedical field. Several efforts have been focused on the synthesis of particles of this material aiming to the precise control of size and morphology, porosity and surface area. HAp is widely used as an implant for bone tissue regeneration, as a coating for metallic implants and in a drug-controlled release. In this sense, the objective of this review is to gather information related to HAp, providing readers with information about synthesis methods, material characteristics and their applications. Resumo A hidroxiapatita (HAp) é uma biocerâmica amplamente estudada devido à sua similaridade química com o componente mineral dos ossos. Além disso, é biocompatível, bioativa e termodinamicamente estável no fluido corporal, o que a coloca como um material atraente para uma ampla gama de aplicações no campo biomédico. Diversos esforços têm sido focados na síntese de partículas deste material visando o controle preciso de tamanho e morfologia, porosidade e área superficial. HAp é amplamente utilizada como implante para a regeneração do tecido ósseo, como revestimento para implantes metálicos e na liberação controlada de drogas. Neste sentido, o objetivo desta revisão é reunir informações relacionadas à HAp, fornecendo aos leitores informações sobre os métodos de síntese, características do material e suas aplicações.

CERVOXY COLL; International audience; A growing interest is currently directed to find an efficient NO and CO2 gas carriers for biomedical applications. The gas adsorption properties of sodium- (Na-X) and copper- (Cu-X) containing FAU nanozeolites toward nitric oxide and carbon dioxide were studied. The materials were fully characterised by XRD, TEM, ICP, DLS and in-situ FTIR. The as-prepared Na-X showed higher gas adsorption ability towards carbon dioxide, whereas the ion-exchanged Cu-X was more efficient adsorbent with regards to nitric oxide. In addition, the cytotoxicity tests disclosed that both nanozeolites have no toxicity making them suitable for further tests in biomedical field as gas transporters.

A sponge template method was used to synthesize scaffolds from hydroxyapatite (HAp) using varying sintering temperatures and compressive ratios. The HAp scaffolds were fabricated with collagen (COL) or collagen/HAp particles under room temperature coating conditions. The microstructure and mechanical properties of the fabricated biomaterials were analyzed by FE-SEM and EZ Test, respectively. The FE-SEM micrographs showed microporous structure of the fabricated composite scaffolds. Incorporation of COL or COL/HAp into pure HAp scaffolds under coating conditions significantly reduced the porosity and enhanced the mechanical properties. The results demonstrated that the porosity of fabricated scaffolds was reduced by lowering the compressive pressure and increasing the sintering temperature. The maximum estimated compressive moduli at 1000, 1100 and 1200 °C for HAp-COL and HAp-COL/HAp composite scaffolds were 4.36, 2.93, 5.09 MPa and 4.57, 8.19, 5.02 MPa, respectively, at a 50% compressive ratio. It was assumed that porosity was effectively reduced to the maximum level at a 50% compressive ratio. An in vitro stem cell study showed significant cell adhesion and proliferation over the fabricated HAp-COL and HAp-COL/HAp composite scaffolds. These results confirmed that fabrication of pure HAp with COL and COL/HAp materials had advanced effects on the mechanical properties of fabricated porous composite scaffolds.

Acknowledgments: This research work was supported by the Portuguese Foundation for Science & Technology (FCT) through the Project references CMUP-ERI/TIC/0021/2014 and UID/Multi/04044/2013. In addition, the authors would like to thank Portuguese National Innovation Agency (ANI) through the Project reference POCI-01-0247-FEDER-017963 and European Regional Development Fund (FEDER), through COMPETE2020 under the PT2020 program (POCI-01-0145-FEDER-023423). The authors (MYK and GBH) acknowledge the financial support of UGC, New Delhi under UPE-FAR-I Program [F. No. 14-3/2012 (NS/PE)] and DST, New Delhi under DST-PURSE-Phase-II Program [F. No. SR/PURSE Phase 2/13(G)]. This review describes available smart biomaterials for biomedical applications. Biomaterials have gained special attention because of their characteristics, along with biocompatibility, biodegradability, renewability, and inexpensiveness. In addition, they are also sensitive towards various stimuli such as temperature, light, magnetic, electro, pH and can respond to two or more stimuli at the same time. In this manuscript, the suitability of stimuli-responsive smart polymers was examined, providing examples of its usefulness in the biomedical applications. info:eu-repo/semantics/publishedVersion

Owing to their superior mechanical strength and structure similarity to the extracellular matrix, nanocelluloses as a class of emerging biomaterials have attracted great attention in three-dimensional (3D) bioprinting to fabricate various tissue mimics. Yet, when printing complex geometries, the desired ink performance in terms of shape fidelity and object resolution demands a wide catalogue of tunability on the material property. This paper describes surface engineered biomimetic inks based on cellulose nanofibrils (CNFs) and cross-linkable hemicellulose derivatives for UV-aided extrusion printing, being inspired by the biomimetic aspect of intrinsic affinity of heteropolysaccharides to cellulose in providing the ultrastrong but flexible plant cell wall structure. A facile aqueous-based approach was established for the synthesis of a series of UV cross-linkable galactoglucomannan methacrylates (GGMMAs) with tunable substitution degrees. The rapid gelation window of the formulated inks facilitates the utilization of these wood-based biopolymers as the feeding ink for extrusion-based 3D printing. Most importantly, a wide and tunable spectrum ranging from 2.5 to 22.5 kPa of different hydrogels with different mechanical properties could be achieved by varying the substitution degree in GGMMA and the compositional ratio between GGMMA and CNFs. Used as the seeding matrices in the cultures of human dermal fibroblasts and pancreatic tumor cells, the scaffolds printed with the CNF/GGMMA inks showed great cytocompatibility as well as supported the matrix adhesion and proliferative behaviors of the studied cell lines. As a new family of 3D printing feedstock materials, the CNF/GGMMA ink will broaden the map of bioinks, which potentially meets the requirements for a variety of in vitro cell-matrix and cell-cell interaction studies in the context of tissue engineering, cancer cell research, and high-throughput drug screening.

Photo-crosslinked synthetic biodegradable polymer networks are highly interesting materials for utilization in biomedical applications such as drug delivery, cell encapsulation and tissue engineering scaffolds. Varying the architecture, chemistry, degree of functionalization and molecular weight of the macromer precursor molecules results in networks with a wide range of physical- and mechanical properties, crosslinking densities, degradation characteristics and thus in potential applications. Photo-crosslinked networks can easily be prepared and have the possibility to entrap a wide range of (biologically active) substances and cells. Additionally, spatial and temporal control over the crosslinking process when using additive manufacturing processes, allows for the preparation of network structures with complex shapes. Photo-crosslinked networks have been used to prepare drug delivery devices, as these networks allow for drug delivery in a controlled way over a prolonged period of time. Furthermore, additive manufacturing techniques such as extrusion-based additive manufacturing and stereolithography have been used to prepare photo-crosslinked tissue engineering scaffolds. This allows for the preparation of designed porous structures with precise control over the pore size and pore architecture and optimal mechanical properties. In particular for stereolithography, a wide variety of resins based on biodegradable photo-crosslinkable macromers has been developed.

In order to improve the drawbacks related to hydrogels, nanocomposite hydrogels were developed by incorporating different types of nanoparticles or nanostructures in the hydrogel network. This review categorizes nanocomposite hydrogels based on the type of their nanoparticle into four groups of carbon-, polymeric-, inorganic- and metallic-based nanocomposite hydrogels. Each type has specific properties that make them appropriate for a special purpose. This is mainly attributed to the improvement of interactions between nanoparticles and polymeric chains and to the enhancement of desirable properties for target applications. The focus of this paper is on biomedical applications of nanocomposite hydrogels and the most recent approaches made to fulfill their current limitations.

Most vaccines developed today include only the antigens that best stimulate the immune system rather than the entire virus or microbe, which makes vaccine production and use safer and easier, though they lack potency to induce acceptable immunity and long-term protection. The incorporation of additional immune stimulating components, named adjuvants, is required to generate a strong protective immune response. Nucleic acids (DNA and RNA) and their synthetic analogs are promising candidates as vaccine adjuvants activating Toll-like receptors (TLRs). Additionally, in the last few years several nanocarriers have emerged as platforms for targeted co-delivery of antigens and adjuvants. In this review, we focus on the recent developments in polymer nanomaterials presenting nucleic acids as vaccine adjuvants. We aim to compare the effectiveness of the various classes of polymers in immune modulating materials (nanoparticles, dendrimers, single-chain particles, nanogels, polymersomes and DNA-based architectures). In particular, we address the critical role of parameters such as size, shape, complexation and release of TLR ligands, cellular uptake, stability, toxicity and potential importance of spatial control in ligand presentation.

Magnetic interactions can play an important role in the heating efficiency of magnetic nanoparticles. Although most of the time interparticle magnetic interactions are a dominant source, in specific cases such as multigranular nanostructures intraparticle interactions are also relevant and their effect is significant. In this work, we have prepared two different multigranular magnetic nanostructures of iron oxide, nanorings (NRs) and nanotubes (NTs), with a similar thickness but different lengths (55 nm for NRs and 470 nm for NTs). In this way, we find that the NTs present stronger intraparticle interactions than the NRs. Magnetometry and transverse susceptibility measurements show that the NTs possess a higher effective anisotropy and saturation magnetization. Despite this, the AC hysteresis loops obtained for the NRs (0?400 Oe, 300 kHz) are more squared, therefore giving rise to a higher heating efficiency (maximum specific absorption rate, SARmax = 110 W/g for the NRs and 80 W/g for the NTs at 400 Oe and 300 kHz). These results indicate that the weaker intraparticle interactions in the case of the NRs are in favor of magnetic hyperthermia in comparison with the NTs. This research was funded by the Vietnam National Foundation for Science and Technology Development (NAFOSTED), grant number 103.02-2019.314. The Spanish Government is acknowledged for the “Nanotechnology in translational hyperthermia (HIPERNANO)” research network (RED2018-102626-T) and for funding under the project number MAT2017-83631-C3. Research at USF was supported by US Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, Award No. DE-FG02-07ER46438. Basque Government is also acknowledged for funding under the project number IT-1005-16 and for the postdoctoral fellowship POS_2020_1_0028.

Over the past years, biomaterials-based nano cues with multi-functional characteristics have been engineered with high interest. The ease in fine tunability with maintained compliance makes an array of nano-bio materials supreme candidates for the biomedical sector of the modern world. Moreover, the multi-functional dimensions of nano-bio elements also help to maintain or even improve the patients’ life quality most securely by lowering or diminishing the adverse effects of in practice therapeutic modalities. Therefore, engineering highly efficient, reliable, compatible, and recyclable biomaterials-based novel corrective cues with multipurpose applications is essential and a core demand to tackle many human health-related challenges, e.g., the current COVID-19 pandemic. Moreover, robust engineering design and properly exploited nano-bio materials deliver wide-ranging openings for experimentation in the field of interdisciplinary and multidisciplinary scientific research. In this context, herein, it is reviewed the applications and potential on tissue engineering and therapeutics of COVID-19 of several biomaterials. Following a brief introduction is a discussion of the drug delivery routes and mechanisms of biomaterials-based nano cues with suitable examples. The second half of the review focuses on the mainstream applications changing the dynamics of 21st century materials. In the end, current challenges and recommendations are given for a healthy and foreseeable future.

Multilayered [FeNi (100 nm)/Cu (3 nm)]5/Cu (500 nm)/[Cu (3 nm)/[FeNi (100 nm)]5 structures were used as sensitive elements of the magnetoimpedance (MI) sensor prototype for model experiments of the detection of magnetic particles in blood vessel. Non-ferromagnetic cylindrical polymer rod with a small magnetic inclusion was used as a sample mimicking thrombus in a blood vessel. The polymer rod was made of epoxy resin with an inclusion of an epoxy composite contain-ing 30% weight fraction of commercial magnetite microparticles. The position of the magnetic inclusion mimicking thrombus in the blood vessel was detected by the measurements of the stray magnetic fields of microparticles using MI element. Changes of the MI ratio in the presence of composite can be characterized by the shift and the decrease of the maximum value of the MI. We were able to detect the position of the magnetic composite sample mimicking thrombus in blood vessels. Comsol modeling was successfully used for the analysis of the obtained experimental results and the understanding of the origin the MI sensitivity in proposed configuration. We describe possible applications of studied configuration of MI detection for biomedical applications in the field of thrombus state evaluation and therapy. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This research was in part founded by Russian Science Foundation, grant number 18-19-00090 and in part by the Ministry of Science and Higher Education of the Russian Federation (project No. FEUZ -2020-0051) and Proyecto Elkartek AVANSITE of the Basque Government.