Improving the properties of fish skin collagen/silk fibroin dressing by chemical treatment for corneal wound healing

Development of silk fibroin/collagen film containing GI-20 peptide-loaded PLGA nanoparticles against corneal herpes simplex virus-1

Herpes simplex virus-1 (HSV-1) is the primary cause of infectious blindness. Despite impressive therapeutic outcomes of conventional treatments, HSV-1 drug resistance can be easily developed. Thus, more constructive strategies should be implemented. Led by this inspiration, this work describes the potential utility of a biodegradable silk fibroin/collagen (SF/Col) film combined with GI-20-loaded poly lactic-co-glycolic acid (PLGA) nanoparticle to provide efficient and sustained delivery platform for synthetic GI-20 peptide against HSV-1. A non-irritant film containing 90 % SF and 10 % Col incorporated with mentioned nanodrug showed some optimum physicochemical properties including loading efficiency (74.15 % ± 1.12), tensile strength (3.16 ± 0.67 MPa), water uptake ability (∼73 %), cytocompatibility (viable up to 35 µg/mL of GI-20), and sustained release paradigm (∼90 % within 14 days). Also, GI-20 peptide at concentration of 35 µg/mL could prophylactically attenuate viral titration by 5 log10 units. In addition, the corneal uptake was improved without vascular irritation. In accordance with in vitro results, no hallmarks of keratitis and significant neovascularization along with ignorable inflammatory responses were obtained. Taken together, these results could guarantee the potential of mentioned multifunctional biomaterial in the healing of infected corneal tissue.

Critical roles of small silk fibroin molecules in the self-assembly and properties of regenerated silk fibroin

Silk is primarily composed of silk fibroin (SF) and silk sericin (SS), with SF significantly contributing to the mechanical properties of silk fibers. SF consists of the large molecular fibroin heavy chain (Fib-H), small molecular fibroin light chain (Fib-L), and P25 protein. Degumming is a crucial step in both the silk reeling process and the preparation of regenerated silk fibroin (RSF), but it can cause damage to Fib-H. This study investigates how degumming affects small SF molecules and their influence on the properties of silk fibers and RSF. A gradient degumming treatment using various reagents was employed. SS antibody detection indicated that 3 g/L papain and sodium carbonate (Na2CO3) at concentrations ≥0.2 % almost completely removed SS. SF antibody detection revealed that Na2CO3 degumming severely damaged Fib-H and degraded Fib-L and P25. While tensile tests showed that this damage did not significantly affect the mechanical properties of SF fibers, the loss of small SF molecules reduced the mechanical properties of the RSF membranes and delayed RSF gelation. Atomic force microscopy demonstrated that RSF containing Fib-H of similar molecular weight (100-180 kDa) can self-assemble into nanofibrils when small SF molecules are present, whereas 0.5 % Na2CO3-degummed RSF lacking these small SF molecules cannot form nanofibrils. By adding additional small SF molecules to the 0.5 % Na2CO3-degummed RSF, nanofibrils can be formed. This research highlights the critical role of small SF molecules in the properties of RSF and provides a theoretical foundation for the development of RSF-derived materials.

Trends in protein derived materials for wound care applications

Natural resource based polymers, especially those derived from proteins, have attracted significant attention for their potential utilization in advanced wound care applications. Protein based wound care materials provide superior biocompatibility, biodegradability, and other functionalities compared to conventional dressings. The effectiveness of various fabrication techniques, such as electrospinning, phase separation, self-assembly, and ball milling, is examined in the context of developing protein-based materials for wound healing. These methods produce a wide range of forms, including hydrogels, scaffolds, sponges, films, and bioinspired nanomaterials, each designed for specific types of wounds and different stages of healing. This review presents a comprehensive analysis of recent research that investigates the transformation of proteins into materials for wound healing applications. Our focus is on essential proteins, such as keratin, collagen, gelatin, silk, zein, and albumin, and we emphasize their distinct traits and roles in wound care management. Protein-based wound care materials show promising potential in biomedical engineering, offering improved healing capabilities and reduced risks of infection. It is crucial to explore the potential use of these materials in clinical settings while also addressing the challenges that may arise from their commercialization in the future.

Silk fibroin/vitreous humor hydrogel scaffold modified by a carbodiimide crosslinker for wound healing

Natural-derived biomaterials can be used as substrates for the growth, proliferation, and differentiation of cells. In this study, bovine vitreous humor as a biological material was cross-linked to silk fibroin with different concentration ratios to design a suitable substrate for corneal tissue regeneration. The cross-linked samples were evaluated with different analyses such as structural, physical (optical, swelling, and degradation), mechanical, and biological (viability, cell adhesion) assays. The results showed that all samples had excellent transparency, especially those with higher silk fibroin content. Increasing the ratio of vitreous humor to silk fibroin decreased mechanical strength and increased swelling and degradation, respectively. There was no significant difference in the toxicity of the samples, and with the increase in vitreous humor ratio, adhesion and cell proliferation increased. Generally, silk fibroin with vitreous humor can provide desirable characteristics as a transparent film for corneal wound healing.

Proliferation and differentiation of Wharton's jelly-derived mesenchymal stem cells on prgf-treated hydrogel scaffold

BACKGROUND

To address the limitations of Cultivated Limbal Epithelial Transplantation (CLET) and the use of amniotic membrane (AM) in treating Limbal Stem Cell Deficiency (LSCD), we aimed to develop a Collagen/Silk Fibroin (Co/SF) scaffold enriched with Platelet-Rich Growth Factor (PRGF) to support the proliferation, maintenance, and differentiation of Wharton's jelly-derived mesenchymal stem cells (WJMSCs) into corneal epithelial cells (CECs).

METHOD

Scaffolds loaded with PRGF were evaluated through release studies, cytotoxicity assays, and cell differentiation. The proliferation and differentiation of WJMSCs and Limbal Epithelial Stem Cells (LESCs) were investigated using MTT assays, real-time PCR and immunostaining.

RESULTS

The PRGF-loaded Co/SF scaffold significantly promoted the proliferation of both WJMSCs and LESCs in a concentration-dependent manner. Real-time PCR and immune staining revealed a significant increase in the expression of P63, ABCG2, and cytokeratin 3/12 markers in WJMSCs, a significant decrease in the expression of P63 and ABCG2, and a significant increase in the expression of cytokeratin 3/12 markers indicating successful differentiation into CECs.

CONCLUSION

The WJMSC cultured on PRGF-enriched Co/SF scaffold demonstrates potential as a viable alternative to conventional CLET, offering a promising strategy for corneal tissue regeneration.

Improving properties of platelet-rich fibrin scaffold with tannic acid for wound healing

Platelet-rich fibrin (PRF), which is the rich source of growth factors, has been used as an efficient scaffold in tissue engineering and wound healing. In this study, tannic acid as a green cross-linker with different concentrations (0.5%, 1%, 5% and 10%) was used to improve the properties of PRF. The cross-linked gel scaffolds were evaluated by analyses such as scanning electron microscopy, Fourier transform infrared spectroscopy, swelling and degradation, mechanical strength, cell toxicity, cell adhesion and antibacterial test. The results showed that the scaffold structure changes by increasing cross-linker concentration. The swelling rate decreased from 49% to 5% for the samples without the cross-linker and with tannic acid (10%), respectively. The degradation percentage for the cross-linked samples was 8%, which showed a lower degradation rate than the non-cross-linked samples (63%). The mechanical strength of the scaffold with the cross-linker increased up to three times (Young's modulus for the non-cross linked and the cross-linked samples: 0.01 and 0.6 MPa, respectively). Cytotoxicity was not observed up to 10% cross-linker concentration. The cells proliferated well on the cross-linked scaffolds and also showed a good antibacterial effect. In general, tannic acid can improve the physical and mechanical properties of PRF without negatively affecting its biological properties.

Hydrogels in Cutaneous Wound Healing: Insights into Characterization, Properties, Formulation and Therapeutic Potential

Hydrogels are polymeric materials that possess a set of characteristics meeting various requirements of an ideal wound dressing, making them promising for wound care. These features include, among others, the ability to absorb and retain large amounts of water and the capacity to closely mimic native structures, such as the extracellular matrix, facilitating various cellular processes like proliferation and differentiation. The polymers used in hydrogel formulations exhibit a broad spectrum of properties, allowing them to be classified into two main categories: natural polymers like collagen and chitosan, and synthetic polymers such as polyurethane and polyethylene glycol. This review offers a comprehensive overview and critical analysis of the key polymers that can constitute hydrogels, beginning with a brief contextualization of the polymers. It delves into their function, origin, and chemical structure, highlighting key sources of extraction and obtaining. Additionally, this review encompasses the main intrinsic properties of these polymers and their roles in the wound healing process, accompanied, whenever available, by explanations of the underlying mechanisms of action. It also addresses limitations and describes some studies on the effectiveness of isolated polymers in promoting skin regeneration and wound healing. Subsequently, we briefly discuss some application strategies of hydrogels derived from their intrinsic potential to promote the wound healing process. This can be achieved due to their role in the stimulation of angiogenesis, for example, or through the incorporation of substances like growth factors or drugs, such as antimicrobials, imparting new properties to the hydrogels. In addition to substance incorporation, the potential of hydrogels is also related to their ability to serve as a three-dimensional matrix for cell culture, whether it involves loading cells into the hydrogel or recruiting cells to the wound site, where they proliferate on the scaffold to form new tissue. The latter strategy presupposes the incorporation of biosensors into the hydrogel for real-time monitoring of wound conditions, such as temperature and pH. Future prospects are then ultimately addressed. As far as we are aware, this manuscript represents the first comprehensive approach that brings together and critically analyzes fundamental aspects of both natural and synthetic polymers constituting hydrogels in the context of cutaneous wound healing. It will serve as a foundational point for future studies, aiming to contribute to the development of an effective and environmentally friendly dressing for wounds.

Alginate-Based Cryogels for Combined Chemo/Photothermal Antibacterial Therapy and Rapid Hemostasis

As novel wound dressings, cryogels with rapid hemostatic property and good sterilization effect are urgently desirable for wound healing. To reduce the use of antibiotics, antibacterial photothermal therapy with broad-spectrum bactericidal capacity and non-obvious bacterial resistance has been widely researched. However, photothermal agents usually suffer from poor hemostatic ability. In this research, sodium alginate (SA) and epigallocatechin gallate (EGCG) were non-covalently cross-linked in suit by ferric ions to obtain SA/EGCG/Fe (SEF) cryogels after lyophilization as an antibacterial wound dressing. Next, its photothermal performance was intensively assessed. Moreover, its hemostasis and bactericidal effect were evaluated. First, it displayed extraordinary photothermal ability owing to the formation of Fe3+/EGCG-based metal phenolic networks (MPNs) inside the SEF cryogel. Furthermore, in vitro and in vivo assays illustrated that it exhibits rapid hemostatic capacity owing to its high porosity and MPN-mediated cell adhesion capacity. In conclusion, the SEF cryogel manifests satisfactory hemostatic and bactericidal properties. Therefore, it is a promising wound-dressing candidate for clinical applications.