Functional Biomaterials Research Articles

Flow‐Induced Microfluidic Assembly for Advanced Biocatalysis Materials

AbstractExploring the potential of microfluidic systems, this study presents a groundbreaking approach harnessing energy in microfluidic flows within a purpose‐built microreactor, enabling precise deposition of functional biomaterials. Upon optimizing reactor dimensions and integrating it into a microfluidic system, sequentially flow‐induced deposition of DNA hydrogels and transformation into DNA‐protein hybrid materials with SpyTag/SpyCatcher technology is investigated. However, limited functionalization rates restrict its viability for targeted biocatalytic processes. Therefore, the direct deposition of a phenolic acid decarboxylase is investigated, which is efficiently deposited but shows limited biocatalytic performance due to shear‐induced denaturation. This challenge is overcome by a two‐step immobilization process, resulting in microfluidic bioreactors demonstrating initial high space‐time yields of up to 7000 g L−1 d−1, but whose process stability proves unsatisfactory. However, by exploiting the principle of flow‐induced deposition to immobilize recombinant E. coli cells as functional living materials overexpressing biocatalytically relevant enzymes, bioreactors are produced that show equally high space‐time yields in continuous whole‐cell catalysis which remain constant over periods of up to 10 days. The insights gained offer optimization strategies for advanced functional materials and innovative reactor systems holding promise for applications in fundamental materials science, biosensing, and scalable production of microreactors for biocatalysis and bioremediation.

Self-Assembly of Metabolite Nanostructures toward Functional Biomaterials

Self-Assembly of Metabolite Nanostructures toward Functional Biomaterials

Recent Progress in Protein-Polyphenol Assemblies for Biomedical Applications.

Nowadays, natural materials as smart building blocks for assembling functional materials have aroused extensive interest in the scientific community. Proteins and polyphenols are typical natural building blocks that are widely used. On the one hand, proteins are one of the most versatile classes of biomolecules, serving as catalysts, signaling molecules, transporters, receptors, scaffolds that maintain the integrity of cell and tissue, and more. On the other hand, the facile adhesion of naturally abundant polyphenols with other substances and their potential biomedical applications have been highly attractive for functional biomaterials fabrication. Additionally, there are a variety of interactions between the proteins and polyphenols, mainly hydrogen bonding, hydrophobic, and ionic interactions. These reversible dynamic interactions enable proteins and polyphenols to form stable protein-polyphenol assemblies and maintain their inherent structures and biological activities in the assemblies. Therefore, protein-polyphenol assemblies can be applied to design a variety of advanced functional materials for biomedical applications. Herein, recent progress in protein-polyphenol particles, capsules, coatings, and hydrogels is summarized, the preparation and application of these assemblies are introduced in detail, and the future of the field is prospected.

Catalyst-Free Amino-Yne Click Reaction: An Efficient Way for Immobilizing Amoxicillin onto Polymeric Surfaces.

Surface modifications play a crucial role in enhancing the functionality of biomaterials. Different approaches can be followed in order to achieve the bioconjugation of drugs and biological compounds onto polymer surfaces. In this study, we focused on the immobilization of an amoxicillin antibiotic onto the surface of poly-L-lactic acid (PLLA) using a copper-free amino-yne click reaction. The utilization of this reaction allowed for a selective and efficient bioconjugation of the amoxicillin moiety onto the PLLA surface, avoiding copper-related concerns and ensuring biocompatibility. The process involved sequential steps that included surface activation via alkaline hydrolysis followed by an amidation reaction with ethylendiamine, functionalization with propiolic groups, and subsequent conjugation with amoxicillin via a click chemistry approach. Previous amoxicillin immobilization using tryptophan and fluorescent amino acid conjugation was carried out in order to determine the efficacy of the proposed methodology. Characterization techniques such as X-ray photoelectron spectroscopy (XPS), Attenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) spectroscopy, surface imaging, water contact angle determination, and spectroscopic analysis confirmed the successful immobilization of both tryptophan and amoxicillin while maintaining the integrity of the PLLA surface. This tailored modification not only exhibited a novel method for surface functionalization but also opens avenues for developing antimicrobial biomaterials with improved drug-loading capacity.

Encoding Structure in Intrinsically Disordered Protein Biomaterials.

In nature, proteins range from those with highly ordered secondary and tertiary structures to those that completely lack a well-defined three-dimensional structure, termed intrinsically disordered proteins (IDPs). IDPs are generally characterized by one or more segments that have a compositional bias toward small hydrophilic amino acids and proline residues that promote structural disorder and are called intrinsically disordered regions (IDRs). The combination of IDRs with ordered regions and the interactions between the two determine the phase behavior, structure, and function of IDPs. Nature also diversifies the structure of proteins and thereby their functions by hybridization of the proteins with other moieties such as glycans and lipids; for instance, post-translationally glycosylated and lipidated proteins are important cell membrane components. Additionally, diversity in protein structure and function is achieved in nature through cross-linking proteins within themselves or with other domains to create various topologies. For example, an essential characteristic of the extracellular matrix (ECM) is the cross-linking of its network components, including proteins such as collagen and elastin, as well as polysaccharides such as hyaluronic acid (HA). Inspired by nature, synthetic IDP (SynIDP)-based biomaterials can be designed by employing similar strategies with the goal of introducing structural diversity and hence unique physiochemical properties. This Account describes such materials produced over the past decade and following one or more of the following approaches: (1) incorporating highly ordered domains into SynIDPs, (2) conjugating SynIDPs to other moieties through either genetically encoded post-translational modification or chemical conjugation, and (3) engineering the topology of SynIDPs via chemical modification. These approaches introduce modifications to the primary structure of SynIDPs, which are then translated to unique three-dimensional secondary and tertiary structures. Beginning with completely disordered SynIDPs as the point of origin, structure may be introduced into SynIDPs by each of these three unique approaches individually along orthogonal axes or by combinations of the three, enabling bioinspired designs to theoretically span the entire range of three-dimensional structural possibilities. Furthermore, the resultant structures span a wide range of length scales, from nano- to meso- to micro- and even macrostructures. In this Account, emphasis is placed on the physiochemical properties and structural features of the described materials. Conjugates of SynIDPs to synthetic polymers and materials achieved by simple mixing of components are outside the scope of this Account. Related biomedical applications are described briefly. Finally, we note future directions for the design of functional SynIDP-based biomaterials.

Retracted: Recent Advances in Cell and Functional Biomaterial Treatment for Spinal Cord Injury.

[This retracts the article DOI: 10.1155/2022/5079153.].

Water-Based Synthesis of β-Sheet-Like Supramolecular Metallohydrogel Organized by Using a Native Ultrashort Peptide Sequence.

Designing supramolecular hydrogels using short peptides is challenging. To control self-assembly, a certain amount of organic solvent is typically added to the system, or the short peptide is modified with a functional group that is hydrophobic, hydrophilic, or highly coordinative. We discovered that l-His-l-Ile-l-Thr (HIT), a very short unmodified "native" tripeptide, selectively responds to Cu2+ ions in pure water to form a transparent supramolecular metallohydrogel. Circular dichroism analysis revealed that Cu2+ ions, but no other metal species, caused HIT to change from a random-coil-like to a β-sheet-like structure. Other spectroscopic methods were used to characterize the properties of the supramolecular metallohydrogel. These results are expected to facilitate the development of native short peptides as advanced functional biomaterials.

Bioactive compounds and biological functions of medicinal plant-derived extracellular vesicles

Extracellular vesicles (EVs) are tiny lipid bilayer-enclosed membrane particles released from a variety of cell types into the surrounding environment. These EVs have massive participated in cell-to-cell communication and interspecies communication. In recent years, plant-derived extracellular vesicles (PDEVs) and “exosome-like” EVs populations found in distinct plants have attracted widespread attention. Especially, research on medicinal plant-derived extracellular vesicles (MPDEVs) are increasing, which are considered a kind of promising natural compound. This review summarizes current knowledge on MPDEVs in terms of bioactive compounds, including small RNA, protein, lipid, and metabolite, have been found on the surface and/or in the lumen of MPDEVs. Moreover, both in vitro and in vivo experiments have shown that MPDEVs exert broad biomedical functions, such as anti-inflammatory, anticancer, antioxidant, modulate microbiota, etc. MPDEVs may be a better substitute than animal-derived extracellular vesicles (ADEVs) because of safety and biocompatibility in the future.

Highly efficient ZnFe2O4 decorated g-C3N4/GO with biomedical and photocatalytic activities

In this work, a novel magnetic composite was synthesized using graphene oxide (GO), graphitic carbon nitride(g-C3N4), and zinc ferrite (ZnFe2O4) for photocatalytic and biomedical functions. The synthesized nanocomposite (g-C3N4/GO/ZnFe2O4) was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX), UV–Vis diffuse reflectance spectra (DRS), vibrating sample magnetometer (VSM), Brunner-Emmett-Teller theory (BET), and photoluminescence (PL) techniques. Decorating g-C3N4 and GO by ZnFe2O4 as a multi-component photocatalyst with a simple and cost-effective method in our work shows high efficiency, antibacterial, and anticancer activity. The outcome of using the nanocomposite as a novel heterojunction structure, in comparison to other individual photocatalysts, has shown great activity in degrading methylene blue (MB) due to the formation of electron-hole pairs. GO improved the photocatalyst adsorption capacity and life of charge carriers, facilitating the transfer of electrons. Also, ZnFe2O4 increased the separate charges and reusability process by making heterojunction structures. The dye degradation process attained 98 % promising efficiency in only 60 min and just 3.7 % degradation after 30 min in dark conditions. The Plausible mechanism shows the Z-scheme route. Also, practical factors such as pH, concentration, dosage, and scavenger were obtained, and the optimal values were 10, 20 mg/L, 0.3 g/L, and EDTA (Ethylenediamine tetraacetic acid), respectively. The reusability of nanocomposite was also analyzed in 6 cycles. Finally, the nanocomposite made the area of inhibition on Pseudomonas aeruginosa (Gram-negative bacteria) and Bacillus cereus (Gram-positive bacteria) about 18 ± 0.5 mm and 14 ± 0.2 mm, respectively. Also, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay was examined. The MTT assay for breast cancer cell lines showed the survival percentage of cells is between 99.2 % and 61.4 %, so it can be applied as a carrier.

Biobased, self-healing, and recyclable polyurethane derived hydrogel-elastomer hybrids for efficient lubrication

Developing biobased hydrogel-elastomer hybrids with stable lubrication derived from self-healing and recyclable polymer matrix poses a key challenge in the field of medical devices. Herein, we reported a novel hydrogel-elastomer hybrid incorporating a tung oil (TO)-based, self-healing, and recyclable polyurethane (PU) substrate that exhibits exceptional hydrophilic and lubricating properties. Initially, a series of UV-curable PU elastomers containing dynamic hindered urea bonds (HUBs) derived from renewable TO were prepared. By adjusting the ratios of the cross-linking agent TO-based polyol and the chain-extending agent polytetramethyleneglycol, the mechanical and thermal properties of these elastomers could be tuned well. The as-prepared PU elastomers demonstrated remarkable dynamic properties, attributed to the dissociation and recombination of HUBs, enabling efficient self-healing and effective recycling through solvent or hot-pressing methods while preserving their mechanical properties. Furthermore, functional hydrogel-elastomer hybrids were obtained by applying UV-initiated polymerization method to generate hydrogel coatings onto the optimized PU elastomer surface. Compared to the pristine PU material, the resulting hydrogel-elastomer hybrids exhibited excellent lubricity in aqueous environments, resulting from the formation of a robust hydration layer facilitated by electrostatic forces. Overall, our current research work provides key design inspiration for developing next-generation medical devices from sustainable and recyclable functional biomaterials.

Network of cyano-p-aramid nanofibres creates ultrastiff and water-rich hydrospongels.

The structure-property paradox of biological tissues, in which water-rich porous structures efficiently transfer mass while remaining highly mechanically stiff, remains unsolved. Although hydrogel/sponge hybridization is the key to understanding this phenomenon, material incompatibility makes this a challenging task. Here we describe hydrogel/sponge hybrids (hydrospongels) that behave as both ultrastiff water-rich gels and reversibly squeezable sponges. The self-organizing network of cyano-p-aramid nanofibres holds approximately 5,000 times more water than its solid content. Hydrospongels, even at a water concentration exceeding 90 wt%, are hard as cartilage with an elastic modulus of 50-80 MPa, and are 10-1,000 times stiffer than typical hydrogels. They endure a compressive strain above 85% through poroelastic relaxation and hydrothermal pressure at 120 °C. This performance is produced by amphiphilic surfaces, high rigidity and an interfibrillar, interaction-driven percolating network of nanofibres. These features can inspire the development of future biofunctional materials.

Optimization and evaluation of Atrina pectinata polysaccharides recovered by subcritical water extraction: A promising path to natural products

In this study, the recovery of Atrina pectinata posterior adductor polysaccharides (APP-PS) using subcritical water extraction (SWE) was optimized by response surface methodology (RSM) and the physicochemical and biological properties of the recovered APP-PS were evaluated. The optimal extraction conditions, which resulted in a maximum yield of 55.58 ± 1.12 %, were temperature, 152.08 °C; extraction time, 10 min; solid–liquid ratio, 30 g/600 mL. The obtained APP-PS was found to be 88.05 ± 0.17 % total sugar. Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (NMR) analyses confirmed the presence of the α-coordination of D-glucan in the polymer sample. The analysis of monosaccharide composition, along with thermogravimetric analysis, revealed the typical structure of the sample, composed of glucose alone. Total phenolic contents of APP-PS were measured as 5.47 ± 0.01 mg Gallic acid/g of dry sample and total flavonoids contents were determined to be 0.78 ± 0.06 mg Quercetin/g of dry sample. For biological activities, ABTS+, DPPH and FRAP antioxidant activities were measured to be 20.00 ± 0.71, 2.35 ± 0.05 and 4.02 ± 0.07 μg Trolox equivalent/100 g of dry sample, respectively. Additionally ACE inhibitory was confirmed to be 87.02 ± 0.47 %. These results showed that SWE is an effective method to recover biofunctional materials from marine organisms.

Application of metal-organic frameworks-based functional composite scaffolds in tissue engineering.

With the rapid development of materials science and tissue engineering, a variety of biomaterials have been used to construct tissue engineering scaffolds. Due to the performance limitations of single materials, functional composite biomaterials have attracted great attention as tools to improve the effectiveness of biological scaffolds for tissue repair. In recent years, metal-organic frameworks (MOFs) have shown great promise for application in tissue engineering because of their high specific surface area, high porosity, high biocompatibility, appropriate environmental sensitivities and other advantages. This review introduces methods for the construction of MOFs-based functional composite scaffolds and describes the specific functions and mechanisms of MOFs in repairing damaged tissue. The latest MOFs-based functional composites and their applications in different tissues are discussed. Finally, the challenges and future prospects of using MOFs-based composites in tissue engineering are summarized. The aim of this review is to show the great potential of MOFs-based functional composite materials in the field of tissue engineering and to stimulate further innovation in this promising area.

Biomimetic chiral hydrogen-bonded organic-inorganic frameworks

Assembly ubiquitously occurs in nature and gives birth to numerous functional biomaterials and sophisticated organisms. In this work, chiral hydrogen-bonded organic-inorganic frameworks (HOIFs) are synthesized via biomimicking the self-assembly process from amino acids to proteins. Enjoying the homohelical configurations analogous to α-helix, the HOIFs exhibit remarkable chiroptical activity including the chiral fluorescence (glum = 1.7 × 10−3) that is untouched among the previously reported hydrogen-bonded frameworks. Benefitting from the dynamic feature of hydrogen bonding, HOIFs enable enantio-discrimination of chiral aliphatic substrates with imperceivable steric discrepancy based on fluorescent change. Moreover, the disassembled HOIFs after recognition applications are capable of being facilely regenerated and self-purified via aprotic solvent-induced reassembly, leading to at least three consecutive cycles without losing the enantioselectivity. The underlying mechanism of chirality bias is decoded by the experimental isothermal titration calorimetry together with theoretic simulation.

Liquid-liquid phase separation-inspired design of biomaterials.

Liquid-liquid phase separation (LLPS) is a crucial biological process that governs biomolecular condensation, assembly, and functionality within phase-separated aqueous environments. This phenomenon serves as a source of inspiration for the creation of artificial designs in both structured and functional biomaterials, presenting novel strategies for manipulating the structures of functional protein aggregates in a wide range of biomedical applications. This mini review summarizes my past research endeavors, offering a panoramic overview of LLPS-inspired biomaterials utilized in the design of structured materials, the development of cell mimetics, and the advancement of intelligent biomaterials.

Hollow Bismuth Nanoparticle-Loaded Gelatin Hydrogel Regulates M2 Polarization of Macrophages to Promote Infected Wound Healing.

Open wounds face severe bacterial infection, which affects the quality of healing. Photothermal antimicrobial therapy has received increasing attention as a broad-spectrum antimicrobial treatment that can avoid drug resistance. A variety of metallic materials have been used in the development of photothermal agents. However, there are few studies on bismuth as a photothermal agent and its use in tissue repair, so there is still a lack of clear understanding of its biomedical function. Here, a hollow bismuth nanosphere prepared from bismuth metal was developed for drug loading and photothermal antibacterial effect. The photothermal conversion efficiency of the hollow bismuth spheres reached 16.1%, and the bismuth-loaded gelatin-oxidized dextran (ODex)-based hydrogel achieves good antibacterial effects both invivo and invitro. The bismuth-loaded hydrogel can also promote the angiogenesis of human umbilical vein endothelial cells (HUVECs) and improve the proliferation of human keratinocytes cells (HaCaT) and the quality of wound healing. This discovery provides a new idea for the application of metal bismuth in the field of tissue repair and regeneration.

Prospects and Future Scope of Self-healing Composites

A biomaterial is a component that has been developed to interact with biological systems for therapeutic or diagnostic purposes in medicine. Tissue engineering, bioprinting, and regenerative medicine are just a few of the increasingly complex fields where biomaterials are being used. These applications frequently require difficult or even paradoxical combinations of biomaterial qualities that cannot be satisfied by traditional biomaterials. Many novel proposals have been introduced over the past 10 years to make biomaterials self-healing, opening up fresh possibilities for enhancing the functionality of conventional biomaterials. Thus, the selfhealing composite that will be discussed in the present article is one such biomaterial that comes into play. Self-healing composites are composites that automatically heal in the area where damage has occurred. This material draws inspiration from the way our body heals itself through regenerative processes, and these self-healing composites utilise various additional healing methods as well. This paper outlines the various aspects of self-healing composites and their types, with a focus on capsule-based and vascular self-healing systems. As a complement to previous reviews, this paper provides insights into the diverse self-repairing concepts proposed so far, as well as compares the study of healing mechanisms and manufacturing approaches for the assembly of capsule and vascular networks. The current concept of self-healing polymers provides advanced avenues for secure, longer-lasting, and more durable products and parts across a wide range of industries, such as veneers, electronics, transport, and energy

Preparation strategies of mussel-inspired chitosan-based biomaterials for hemostasis.

Chitosan (CS) has been extensively studied in wound care for its intrinsic hemostatic and antibacterial properties. However, CS has limiting hemostasis applications on account of its drawbacks such as poor adhesion in humid environments and water solubility at neutral pH. CS-based biomaterials, inspired by mussel-adhesive proteins, serve as a suggested platform by biomedical science. The reports show that the mussel-inspired CS-based hemostatic structure has negligible toxicity and excellent adhesiveness. Biomedicine has witnessed significant progress in the development of these hemostatic materials. This review summarizes the methods for the modification of CS by mussel-inspired chemistry. Moreover, the general method for preparation of mussel-inspired CS-based biomaterials is briefly discussed in this review. This work is expected to give a better understanding of opportunities and challenges of the mussel-inspired strategy for the functionalization of CS-based biomaterials in hemostasis and wound healing. This review is hoped to provide an important perspective on the preparation of mussel-inspired CS-based hemostatic materials.

Advances in reparative materials for infectious bone defects and their applications in maxillofacial regions.

Infectious bone defects are characterized by the partial loss or destruction of bone tissue resulting from bacterial contaminations subsequent to diseases or external injuries. Traditional bone transplantation and clinical methods are insufficient in meeting the treatment demands for such diseases. As a result, researchers have increasingly focused on the development of more sophisticated biomaterials for improved therapeutic outcomes in recent years. This review endeavors to investigate specific reparative materials utilized for the treatment of infectious bone defects, particularly those present in the maxillofacial region, with a focus on biomaterials capable of releasing therapeutic substances, functional contact biomaterials, and novel physical therapy materials. These biomaterials operate via heightened antibacterial or osteogenic properties in order to eliminate bacteria and/or stimulate bone cells regeneration in the defect, ultimately fostering the reconstitution of maxillofacial bone tissue. Based upon some successful applications of new concept materials in bone repair of other parts, we also explore their future prospects and potential uses in maxillofacial bone repair later in this review. We highlight that the exploration of advanced biomaterials holds promise in establishing a solid foundation for the development of more biocompatible, effective, and personalized treatments for reconstructing infectious maxillofacial defects.

Bio-gel nanoarchitectonics in tissue engineering.

Given the creation of materials based on nanoscale science, nanotechnology must be combined with other disciplines. This role is played by the new concept of nanoarchitectonics, the process of constructing functional materials from nanocomponents. Nanoarchitectonics may be highly compatible with applications in biological systems. Conversely, it would be meaningful to consider nanoarchitectonics research oriented toward biological applications with a focus on materials systems. Perhaps, hydrogels are promising as a model medium to realize nanoarchitectonics in biofunctional materials science. In this review, we will provide an overview of some of the defined targets, especially for tissue engineering. Specifically, we will discuss (i) hydrogel bio-inks for 3D bioprinting, (ii) dynamic hydrogels as an artificial extracellular matrix (ECM), and (iii) topographical hydrogels for tissue organization. Based on these backgrounds and conceptual evolution, the construction strategies and functions of bio-gel nanoarchitectonics in medical applications and tissue engineering will be discussed.