Albumin-based dynamic double cross-linked hydrogel with self-healing property for antimicrobial application

C-phycocyanin and quaternized chitosan based antibiotic-free hydrogels with antioxidant and antibacterial activity for wound healing

Hydrogels with antioxidant and antibacterial activities have received increasing attention in wound healing due to excessive reactive oxygen species (ROS) and bacterial infection are common issues associated with wounds. Herein, we constructed a series of hydrogels with C-phycocyanin (C-PC), quaternized chitosan (QCS) and silk fibroin protein (SF) as matrixes, which with tetrakis hydroxymethyl phosphonium sulfate (THPS) as crosslinking agent to form dynamic covalent bonds with C-PC and SF. The hydrogel exhibited excellent stretchability and compressibility, which with adhesion strength reached 15 ± 3 kPa and rapid self-healing properties. The hydrogel possessed strong antioxidant activity with assessments of DPPH radical-scavenging capacity and total reducing power. In addition, the hydrogel possessed obvious coagulation function and good blood compatibility, which also showed strong antibacterial activity against E. coli and S. aureus. To improve the therapeutic effect, polydeoxyribonucleotide (PDRN) with the ability of promote wound healing was introduced into the hydrogel. The results showed that the hydrogel loading with PDRN possessed high biocompatibility and can promote cell migration. More importantly, the hydrogel loaded with PDRN can effectively promote wound healing by exerting anti-inflammatory and antioxidant effects, which may offer promising potential application value in the field of wound dressing and tissue repair.

Antifouling and antimicrobial wearable electrochemical sweat sensors for accurate dopamine monitoring based on amyloid albumin composite hydrogels

Wearable electrochemical sweat sensors are potentially promising for health monitoring in a continuous and non-invasive mode with high sensitivity. However, due to the complexity of sweat composition and the growth of skin bacteria, the wearable sweat sensors may gradually lose their sensitivity or even fail over time. To deal with this issue, herein, we proposed a new strategy to construct wearable sweat sensors with antifouling and antimicrobial capabilities. Amyloid albumin hydrogels (ABSAG) were doped with two-dimensional (2D) nanomaterial MXene and CeO2 nanorods to obtain the antifouling and antimicrobial amyloid albumin composite hydrogels (ABSACG, CeO2/MXene/ABSAG), and the wearable sensors were prepared by modifying flexible screen-printed electrodes with the ABSACG. Within this sensing system, the hydrophilic ABSAG possesses strong hydration capability, and it can form a hydration layer on the electrode surface to resist biofouling in sweat. The 2D nanomaterial MXene dispersed in the hydrogel endows the hydrogel with good conductivity and electrocatalytic capability, while the doping of CeO2 nanorods further improves the electrocatalytic performance of the hydrogel and also provides excellent antimicrobial capability. The designed wearable electrochemical sensors based on the ABSACG demonstrated satisfying antifouling and antimicrobial abilities, and they were capable of detecting dopamine accurately in human sweat. It is expected that wearable sensors utilizing the antifouling and antimicrobial ABSACG may find practical applications in human body fluids analysis and health monitoring.

Noncontact 3D Bioprinting of Proteinaceous Microarrays for Highly Sensitive Immunofluorescence Detection within Clinical Samples

Immunofluorescence assays are extensively used for the detection of disease-associated biomarkers within patient samples for direct diagnosis. Unfortunately, these 2D microarrays suffer from low repeatability and fail to attain the low limits of detection (LODs) required to accurately discern disease progression for clinical monitoring. While three-dimensional microarrays with increased biorecognition molecule density stand to circumvent these limitations, their viscous component materials are not compatible with current microarray fabrication protocols. Herein, we introduce a platform for 3D microarray bioprinting, wherein a two-step printing approach enables the high-throughput fabrication of immunosorbent hydrogels. The hydrogels are composed entirely of cross-linked proteins decorated with clinically relevant capture antibodies. Compared to two-dimensional microarrays, these proteinaceous microarrays offer 3-fold increases in signal intensity. When tested with clinically relevant biomarkers, ultrasensitive single-plex and multiplex detection of interleukin-6 (LOD 0.3 pg/mL) and tumor necrosis factor receptor 1 (LOD 1 pg/mL) is observed. When challenged with clinical samples, these hydrogel microarrays consistently discern elevated levels of interleukin-6 in blood plasma derived from patients with systemic blood infections. Given their easy-to-implement, high-throughput fabrication, and ultrasensitive detection, these three-dimensional microarrays will enable better clinical monitoring of disease progression, yielding improved patient outcomes.

Albumin-Based Hydrogel Films Covalently Cross-Linked with Oxidized Gellan with Encapsulated Curcumin for Biomedical Applications

Bovine serum albumin (BSA) hydrogels are non-immunogenic, low-cost, biocompatible, and biodegradable. In order to avoid toxic cross-linking agents, gellan was oxidized with NaIO4 to obtain new functional groups like dialdehydes for protein-based hydrogel cross-linking. The formed dialdehyde groups were highlighted with FT-IR and NMR spectroscopy. This paper aims to investigate hydrogel films for biomedical applications obtained by cross-linking BSA with oxidized gellan (OxG) containing immobilized β-cyclodextrin-curcumin inclusion complex (β-CD-Curc) The β-CD-Curc improved the bioavailability and solubility of Curc and was prepared at a molar ratio of 2:1. The film's structure and morphology were evaluated using FT-IR spectroscopy and SEM. The swelling degree (Q%) values of hydrogel films depend on hydrophilicity and pH, with higher values at pH = 7.4. Additionally, the conversion index of -NH2 groups into Schiff bases increases with an increase in OxG amount. The polymeric matrix provides protection for Curc, is non-cytotoxic, and enhances antioxidant activity. At pH = 5.5, the skin permeability and release efficiency of encapsulated curcumin were higher than at pH = 7.4 because of the interaction of free aldehyde and carboxylic groups from hydrogels with amine groups from proteins present in the skin membrane, resulting in a better film adhesion and more efficient curcumin release.

Research progress of protein complex systems and their application in food: A review

Among the common natural biomolecules, the excellent properties of proteins have attracted extensive attention from researchers for functional applications, however, in native form proteins have many limitations in the performance of their functional attribute. However, with the deepening of research, it has been found that the combination of natural active substances such as polyphenols, polysaccharides, etc. with protein molecules will make the composite system have stronger functional properties, while the utilization of pH-driven method, ultrasonic treatment, heat treatment, etc. not only provides a guarantee for the overall protein-based composite system, but also gives more possibilities to the protein-composite system. Protein composite systems are emerging in the fields of novel active packaging, functional factor delivery systems and gel systems with high medical value. The products of these protein composite systems usually have high functional properties, mainly due to the interaction of the remaining natural active substances with protein molecules, which can be broadly categorized into covalent interactions and non-covalent interactions, and which, despite the differences in these interactions, together constitute the cornerstone for the stability of protein composite systems and for in-depth research.

Applications of human and bovine serum albumins in biomedical engineering: A review

Serum albumin, commonly recognized as a predominant major plasma protein, is ubiquitously distributed among vertebrates, demonstrating versatility and widespread accessibility. Numerous studies have discussed the composition and attributes of human and bovine serum albumin; nonetheless, few systematic and comprehensive summaries on human and bovine serum albumin exist. This paper reviews the applications of human and bovine serum albumin in biomedical engineering. First, we introduce the differences in the structure of human and bovine serum albumin. Next, we describe the extraction methods for human and bovine serum albumin (fractionation process separation, magnetic adsorption, reverse micellar (RM) extraction, and genetic engineering) and the advantages and disadvantages of recently developed extraction methods. The characteristics of different processing forms of human and bovine serum albumin are also discussed, concomitantly elucidating their intrinsic properties, functions, and applications in biomedicine. Notably, their pivotal functions as carriers for drugs and tissue-engineered scaffolds, as well as their contributions to cell reproduction and bioimaging, are critically examined. Finally, to provide guidance for researchers in their future work, this review summarizes the current state of human and bovine serum albumin research and outlines potential future research topics.

Research progress on albumin-based hydrogels: Properties, preparation methods, types and its application for antitumor-drug delivery and tissue engineering

Albumin is derived from blood plasma and is the most abundant protein in blood plasma, which has good mechanical properties, biocompatibility and degradability, so albumin is an ideal biomaterial for biomedical applications, and drug-carriers based on albumin can better reduce the cytotoxicity of drug. Currently, there are numerous reviews summarizing the research progress on drug-loaded albumin molecules or nanoparticles. In comparison, the study of albumin-based hydrogels is a relatively small area of research, and few articles have systematically summarized the research progress of albumin-based hydrogels, especially for drug delivery and tissue engineering. Thus, this review summarizes the functional features and preparation methods of albumin-based hydrogels, different types of albumin-based hydrogels and their applications in antitumor drugs, tissue regeneration engineering, etc. Also, potential directions for future research on albumin-based hydrogels are discussed.

Amyloid-Based Albumin Hydrogels

Amyloid fibrils may serve as building blocks for the preparation of novel hydrogel materials from abundant, low-cost, and biocompatible polypeptides. This work presents the formation of physically cross-linked, self-healing hydrogels based on bovine serum albumin at room temperature through a straightforward disulfide reduction step induced by tris (2-carboxyethyl) phosphine hydrochloride. The structure and surface charge of the amyloid-like fibrils is determined by the pH of the solution during self-assembly, giving rise to hydrogels with distinct physicochemical properties. The hydrogel surface can be readily functionalized with the extracellular matrix protein fibronectin and supports cell adhesion, spreading, and long-term culture. This study offers a simple, versatile, and inexpensive method to prepare amyloid-based albumin hydrogels with potential applications in the biomedical field.

Emerging albumin hydrogels as personalized biomaterials

Developing biomaterials-based tissue engineering scaffolds with personalized features and intrinsic biocompatibility is appealing and urgent. Through utilizing various strategies, albumin, as the most abundant protein in plasma, could be fabricated into sustainable, cost-effective, and potentially personalized hydrogels that would display enormous biological applications. To date, much of the albumin-based research is primarily engrossed in using albumin as a therapeutic molecule or a drug carrier, not much as a scaffold for tissue engineering. For this reason, we have come up with a detailed and insightful review of recent progress in albumin-based hydrogels having an emphasis on production techniques, material characteristics, and biological uses. It is envisioned that albumin-based scaffolds would be appealing and useful platforms to meet current tissue engineering needs and achieve the goal of clinical translation to benefit patients. STATEMENT OF SIGNIFICANCE: The creation of autologous material-based scaffolds is a potential method for preventing immunological reactions and obtaining the best therapeutic results. Patient-derived albumin hydrogels may consequently provide improved opportunities for personalized treatment due to their abundant supply and minimal immunogenicity. To provide a detailed and insightful summary on albumin-based hydrogels, this review includes latest comprehensive information on their preparation procedures, features, and applications in 3D printing and other biomedical applications. The challenges, along with the future potential for implementing albumin-based hydrogels in clinics, have also been addressed.

A facile and general method for synthesis of antibiotic-free protein-based hydrogel: Wound dressing for the eradication of drug-resistant bacteria and biofilms

Antibacterial protein hydrogels are receiving increasing attention in the aspect of bacteria-infected-wound healing. However, bacterial drug resistance and biofilm infections lead to hard healing of wounds, thus the construction of biological agents that can overcome these issues is essential. Here, a simple and universal method to construct antibiotic-free protein hydrogel with excellent biocompatibility and superior antibacterial activity against drug-resistant bacteria and biofilms was developed. The green industrial microbicide tetrakis (hydroxymethyl) phosphonium sulfate (THPS) as cross-linking agent can be quickly cross-linked with model protein bovine serum albumin (BSA) to form antibacterial hydrogel through simple mixing without any other initiators, subsequently promoting drug-resistance bacteria-infected wound healing. This simple gelatinization strategy allows at least ten different proteins to form hydrogels (e.g. BSA, human serum albumin (HSA), egg albumin, chymotrypsin, trypsin, lysozyme, transferrin, myohemoglobin, hemoglobin, and phycocyanin) under the same conditions, showing prominent universality. Furthermore, drug-resistance bacteria and biofilm could be efficiently destroyed by the representative BSA hydrogel (B-Hydrogel) with antibacterial activity, overcoming biofilm-induced bacterial resistance. The in vivo study demonstrated that the B-Hydrogel as wound dressing can promote reepithelization to accelerate the healing of methicillin-resistant staphylococcus aureus (MRSA)-infected skin wounds without inducing significant side-effect. This readily accessible antibiotic-free protein-based hydrogel not only opens an avenue to provide a facile, feasible and general gelation strategy, but also exhibits promising application in hospital and community MRSA disinfection and treatment.

Injectable redox albumin-based hydrogel with in-situ loaded dihydromyricetin

Albumin is widely used in clinics due to its demonstrated biological safety and functional flexibility. Hydrogels derived from natural albumin possess high moisture retention ability and good biodegradability, making albumin ideal biomaterials compared with synthetic polymers. Herein, by reducing disulfide bonds in bovine serum albumin molecules with glutathione and re-oxidizing the free thiols using dimethyl sulfoxide (DMSO) as additional oxidant, three-dimensional network was assembled, leading to the formation of hydrogel. Meanwhile, DMSO is also an excellent solvent for many drugs, and the hydrophobic drug dihydromyricetin (DMY) can be well dissolved in DMSO. During the crosslinking reaction, DMSO participated in fabricating a porous albumin hydrogel network. At the same time, increased loading of DMY and sustained release of DMY were achieved, improving bioavailability of hydrophobic drug DMY. Rheological test and cytotoxicity assay proved excellent elasticity and biocompatibility of the hydrogel. Self-healing property and narrow-needle injection provided potential application of the hydrogel as biomedical materials. This method for formation hydrogels and in situ loading of drugs may expand to preparing other drug loaded hydrogels and find wide applications.

New Materials Based on Molecular Interaction between Hyaluronic Acid and Bovine Albumin

In this work, the interactions between hyaluronic acid and bovine serum albumin were investigated. The film-forming properties of the mixture were proven, and the mechanical and surface properties of the films were measured. The results showed the interactions between hyaluronic acid and albumin, mainly by hydrogen bonds. Molecular docking was used for the visualization of the interactions. The films obtained from the mixture of hyaluronic acid possessed different properties to films obtained from the single component. The addition of bovine serum albumin to hyaluronic acid led to a decrease in the mechanical properties, and to an increase in the surface roughness of the film. The new materials that have been obtained by blending can form a new group of materials for biomedicine and cosmetology.

Multi-crosslinked hydrogels with instant self-healing and tissue adhesive properties for biomedical applications

Due to the defects like long gelling time, inferior mechanical properties and weak adhesion, in-situ forming hydrogels are still restricted in biomedical applications like viscera rupture and targeted therapy. To address these problems, a new kind of multi-crosslinked hydrogel (G-OKG-DA) consisting of gelatin, oxidized konjac glucomannan (OKG), and dopamine (DA) is proposed in this study. The resulting hybrid hydrogel is endowed with a short gelling time (about 3 min) and injectable capacity. According to the mechanical and adhesive tests, G-OKG-DA hydrogel shows a robust tensile strength of 23.94 kPa, as well as a higher adhesive strength (around 150 kPa) than commercial fibrin glue. In addition, an instant self-healing behavior of G-OKG-DA hydrogel can be found, which is attributed to multi-crosslinking reactions including Schiff-base dynamic covalent bonds between OKG and gelatin, oxidative polymerization of DA, and catechol-mediated chemistry like Michael addition and DA-quinone coupling. Importantly, the multi-crosslinked hydrogel will not compromise its hemocompatibility and cytocompatibility in vitro, suggesting potential applications in biomedical fields as tissue adhesive and implants. This article is protected by copyright. All rights reserved.

Color-tunable, self-healing albumin-based lanthanide luminescent hydrogels fabricated by reductant-triggered gelation

Luminescent hydrogels show extensive applications in many fields because of their excellent optical properties. Although there are many matrixes used to prepare luminescent hydrogels, the synthesis of protein-based luminescent hydrogels is still urgently needed to explore due to their good biodegradability and biocompatibility. In this work, a color-tunable, self-healing protein-based luminescent hydrogel consisting of bovine serum albumin (BSA) and lanthanide complexes is prepared via reductant-triggered gelation. Firstly, a bifunctional organic ligand named 4-(phenylsulfonyl)-pyridine-2,6-dicarboxylic acid (4-PSDPA) is synthesized, which can react with thiol groups and effectively sensitize the luminescence of Eu³⁺ and Tb³⁺ ions. Then, the BSA is treated with a reducing agent tris(2-carboxyethyl)phosphine (TCEP) to produce thiol groups. And the newly formed thiol groups can re-match to form disulfide bonds between two BSA molecules or react with Ln(4-PSDPA)₃ complexes, resulting in the formation of an albumin-based luminescent hydrogel. Furthermore, the self-healing, biodegradability and biocompatibility of albumin-based hydrogels have also been demonstrated. We expect that the newly developed multifunctional protein-based hydrogels will find potential applications in the fields of biomedical engineering and optical devices.

Self-Healing Behavior of Polymer/Protein Hybrid Hydrogels

The paper presents the viscoelastic properties of new hybrid hydrogels containing poly(vinyl alcohol) (PVA), hydroxypropylcellulose (HPC), bovine serum albumin (BSA) and reduced glutathione (GSH). After heating the mixture at 55 °C, in the presence of GSH, a weak network is formed due to partial BSA unfolding. By applying three successive freezing/thawing cycles, a stable porous network structure with elastic properties is designed, as evidenced by SEM and rheology. The hydrogels exhibit self-healing properties when the samples are cut into two pieces; the intermolecular interactions are reestablished in time and therefore the fragments repair themselves. The effects of the BSA content, loaded deformation and temperature on the self-healing ability of hydrogels are presented and discussed through rheological data. Due to their versatile viscoelastic behavior, the properties of PVA/HPC/BSA hydrogels can be tuned during their preparation in order to achieve suitable biomaterials for targeted applications.