Collagen/Polyethylene Oxide Nanofibrous Membranes with Improved Hemostasis and Cytocompatibility for Wound Dressing

Facile preparation and characterization of biodegradable and biocompatible UV shielding transdermal patches based on natural rubber latex- dextrin blends

The physico-chemical and biological properties of natural rubber latex (NRL), entailing its biodegradability and biocompatibility, render it a promising material for various biomedical applications. This research explores the facile blending of NRL with dextrin in different compositions to investigate its potential as a prospective UV shielding transdermal patch for biomedical applications. The superior compatibility between the polymers after blending and the improved thermal stability have been established through FTIR, DSC, and TGA examinations, respectively. Optimization of blended polymers for compatibility, wettability, crystallinity, and static mechanical properties has been performed. Morphology characterization conducted via SEM and AFM techniques suggests a uniform morphology for the optimized blend system. The UV shielding ability of the blend has been confirmed by the evaluation of in-vitro UV shielding performance, UV protection factor (UPF), and the superior protection of the optimized system on living cells upon UV irradiation. The observed cell viability, swelling, erosion, porosity, hemocompatibility, and soil degradation properties suggest the NRL-DXT combination for the possible development of high-quality transdermal patches.

Fabrication of Electrospun Double Layered Biomimetic Collagen-Chitosan Polymeric Membranes with Zinc-Doped Mesoporous Bioactive Glass Additives

Several therapeutic approaches have been developed to promote bone regeneration, including guided bone regeneration (GBR), where barrier membranes play a crucial role in segregating soft tissue and facilitating bone growth. This study emphasizes the importance of considering specific tissue requirements in the design of materials for tissue regeneration, with a focus on the development of a double-layered membrane to mimic both soft and hard tissues within the context of GBR. The hard tissue-facing layer comprises collagen and zinc-doped bioactive glass to support bone tissue regeneration, while the soft tissue-facing layer combines collagen and chitosan. The electrospinning technique was employed to achieve the production of nanofibers resembling extracellular matrix fibers. The production of nano-sized (~116 nm) bioactive glasses was achieved by microemulsion assisted sol-gel method. The bioactive glass-containing layers developed hydroxyapatite on their surfaces starting from the first week of simulated body fluid (SBF) immersion, demonstrating that the membranes possessed favorable bioactivity properties. Moreover, all membranes exhibited distinct degradation behaviors in various mediums. However, weight loss exceeding 50% was observed in all tested samples after four weeks in both SBF and phosphate-buffered saline (PBS). The double-layered membranes were also subjected to mechanical testing, revealing a tensile strength of approximately 4 MPa. The double-layered membranes containing zinc-doped bioactive glass demonstrated cell viability of over 70% across all tested concentrations (0.2, 0.1, and 0.02 g/mL), confirming the excellent biocompatibility of the membranes. The fabricated polymer bioactive glass composite double-layered membranes are strong candidates with the potential to be utilized in tissue engineering applications.

Recent Advances in Topical Hemostatic Materials

Untimely or improper treatment of traumatic bleeding may cause secondary injuries and even death. The traditional hemostatic modes can no longer meet requirements of coping with complicated bleeding emergencies. With scientific and technological advancements, a variety of topical hemostatic materials have been investigated involving inorganic, biological, polysaccharide, and carbon-based hemostatic materials. These materials have their respective merits and defects. In this work, the application and mechanism of the major hemostatic materials, especially some hemostatic nanomaterials with excellent adhesion, good biocompatibility, low toxicity, and high adsorption capacity, are summarized. In the future, it is the prospect to develop multifunctional hemostatic materials with hemostasis and antibacterial and anti-inflammatory properties for promoting wound healing.

Surface modification strategies for improved hemocompatibility of polymeric materials: a comprehensive review

Polymeric biomaterials are a widely used class of materials due to their versatile properties. However, as with all other types of materials used for biomaterials, polymers also have to interact with blood. When blood comes into contact with any foreign body, it initiates a cascade which leads to platelet activation and blood coagulation. The implant surface also has to encounter a thromboinflammatory response which makes the implant integrity vulnerable, this leads to blood coagulation on the implant and obstructs it from performing its function. Hence, the surface plays a pivotal role in the design and application of biomaterials. In particular, the surface properties of biomaterials are responsible for biocompatibility with biological systems and hemocompatibility. This review provides a report on recent advances in the field of surface modification approaches for improved hemocompatibility. We focus on the surface properties of polysaccharides, proteins, and synthetic polymers. The blood coagulation cascade has been discussed and blood - material surface interactions have also been explained. The interactions of blood proteins and cells with polymeric material surfaces have been discussed. Moreover, the benefits as well as drawbacks of blood coagulation on the implant surface for wound healing purposes have also been studied. Surface modifications implemented by other researchers to enhance as well as prevent blood coagulation have also been analyzed.

Preparation of Nile tilapia skin collagen powder by low-temperature and comprehensive evaluation of hemostasis and wound healing

Nile tilapia (hereinafter referred to as tilapia) is a species with high economic value and extensive cultivation. In this study, the low-temperature Nile tilapia skin collagen powder (TSCP) was prepared by liquid nitrogen freeze pulverization. After physical and chemical analysis of its properties, it was found that its characteristics were similar to those of type I collagen. The three-dimensional helix structure of protein peptide is good and non denatured. It shows that cryogenic temperature guarantees the activity of TSCP. In addition, TSCP has good biocompatibility. Specifically, it has good blood compatibility, lacks cytotoxicity, will not cause intradermal stimulation and acute systemic toxicity, and has no obvious rejection after implantation. In the rat liver hemorrhage model and wound repair model, compared with the commercially available bovine collagen powder (BSCP), TSCP has better blood coagulation ability: the shortest hemostatic time (135 s) and wound healing efficiency: the wound healing is obvious on the 14th day. The results of this study indicate that the TSCP is an ideal candidate for hemostatic agents and wound healing dressings.

Nanofibrous hemostatic materials: Structural design, fabrication methods, and hemostatic mechanisms

Development of rapid and effective hemostatic materials has always been the focus of research in the healthcare field. Nanofibrous materials which recapitulate the delicate nano-topography feature of fibrin fibers produced during natural hemostatic process, offer large length-to-diameter ratio and surface area, tunable porous structure, and precise control in architecture, showing great potential for staunching bleeding. Here we present a comprehensive review of advances in nanofibrous hemostatic materials, focusing on the following three important parts: structural design, fabrication methods, and hemostatic mechanisms. This review begins with an introduction to the physiological hemostatic mechanism and current commercial hemostatic agents. Then, it focuses on recent progress in electrospun nanofibrous hemostatic materials in terms of composition and structure control, surface modification, and in-situ deposition. The article emphasizes the development of three-dimensional (3D) electrospun nanofibrous materials and their emerging evolution for improving hemostatic function. Next, it discusses the fabrication of self-assembling peptide or protein-mimetic peptide nanofibers, co-assembling supramolecular nanofibers, as well as other nanofibrous hemostatic agents. Further, the article highlights the external and intracavitary hemostatic management based on various nanofiber aggregates. In the end, this review concludes with the current challenges and future perspectives of nanofibrous hemostatic materials. STATEMENT OF SIGNIFICANCE: This article reviews recent advances in nanofibrous hemostatic materials including fabrication methods, composition and structural control, performance improvement, and hemostatic mechanisms. A variety of methods including electrospinning, self-assembly, grinding and refining, template synthesis, and chemical vapor deposition, have been developed to prepare nanofibrous materials. These methods provide robustness in control of the nanofiber architecture in the forms of hydrogels, two-dimensional (2D) membranes, 3D sponges, or composites, showing promising potential in the external and intracavitary hemostasis and wound healing applications. This review will be of great interest to the broad readers in the field of hemostatic materials and multifunctional biomaterials.

Fabrication of chitosan nanofibrous scaffolds based on tannic acid and metal-organic frameworks for hemostatic wound dressing applications

Here, we developed chitosan (CS)-based nanofibrous scaffold consisting of tannic acid (TA) and zinc-based metal-organic framework (MOF) as a novel antibacterial and hemostatic wound dressing. The effect of MOF content and its incorporation within and onto CS/PVA-TA nanofibrous scaffolds were studied. The morphological characterization of fabricated nanofibrous scaffolds revealed the formation of uniform and bead-free nanofibers with an average diameter between 120 and 150 nm. The uniform and continuous decoration of MOF crystals on nanofibrous scaffold surfaces were confirmed by FESEM. The developed nanofibrous scaffolds exhibit appropriate physicochemical characteristics such as chemical and crystalline structure, surface wettability and swelling, and mechanical properties. It is shown that the incorporation of TA and MOFs greatly enhanced the hemostatic performance of the CS/PVA nanofibrous scaffold by providing rapid liquid absorbability and accelerating the aggregation of coagulation factors and platelets. Furthermore, the results of the MTT assay suggested the good biocompatibility of nanofibrous scaffolds containing MOF nanoparticles. The nanofibrous scaffolds exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus. The disk diffusion antibacterial assay showed that the nanofibrous scaffolds containing TA and MOF could protect wound from bacterial infection. The findings provide new insights to develop a MOF-modified nanofibrous structure with great potential for hemostatic wound dressing application.

Enhanced blood coagulation and antibacterial activities of carboxymethyl-kappa-carrageenan-containing nanofibers

Ideal wound dressings should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation. To impart these imperative functions, carboxymethyl-kappa-carrageenan was incorporated into poly(vinyl alcohol) nanofibers (PVA-CMKC). The antibacterial activity of the nanofibers was evaluated. Adsorption of two important blood proteins, fibrinogen and albumin, was also assessed. The adhesion and activation of platelets, and the clotting of whole blood were evaluated to characterize the ability of the nanofibers to promote hemostasis. Adhesion and morphology of both Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using fluorescence microscopy and scanning electron microscopy. CMKC-containing nanofibers demonstrated significant increases in platelet adhesion and activation, percentage of coagulation in whole blood clotting test and fibrinogen adsorption, compared to PVA nanofibers, showing blood coagulation activity. Incorporating CMKC also reduces adhesion and viability of S. aureus and P. aeruginosa bacteria after 24 h of incubation. PVA-CMKC nanofibers show potential application as dressings for wound healing applications.

Hemostatic and Tissue Regeneration Performance of Novel Electrospun Chitosan-Based Materials

The application of chitosan (Ch) as a promising biopolymer with hemostatic properties and high biocompatibility is limited due to its prolonged degradation time, which, in turn, slows the repair process. In the present research, we aimed to develop new technologies to reduce the biodegradation time of Ch-based materials for hemostatic application. This study was undertaken to assess the biocompatibility and hemostatic and tissue-regeneration performance of Ch-PEO-copolymer prepared by electrospinning technique. Chitosan electrospinning membranes (ChEsM) were made from Ch and polyethylene oxide (PEO) powders for rich high-porous material with sufficient hemostatic parameters. The structure, porosity, density, antibacterial properties, in vitro degradation and biocompatibility of ChEsM were evaluated and compared to the conventional Ch sponge (ChSp). In addition, the hemostatic and bioactive performance of both materials were examined in vivo, using the liver-bleeding model in rats. A penetrating punch biopsy of the left liver lobe was performed to simulate bleeding from a non-compressible irregular wound. Appropriately shaped ChSp or ChEsM were applied to tissue lesions. Electrospinning allows us to produce high-porous membranes with relevant ChSp degradation and swelling properties. Both materials demonstrated high biocompatibility and hemostatic effectiveness in vitro. However, the antibacterial properties of ChEsM were not as good when compared to the ChSp. In vivo studies confirmed superior ChEsM biocompatibility and sufficient hemostatic performance, with tight interplay with host cells and tissues. The in vivo model showed a higher biodegradation rate of ChEsM and advanced liver repair.

Collagen-Based Electrospun Materials for Tissue Engineering: A Systematic Review

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.

Biocompatibility, hemostatic properties, and wound healing evaluation of tilapia skin collagen sponges

Dialyzed tilapia skin collagen sponge (DTSCS) and self-assembled tilapia skin collagen sponge (STSCS) were prepared by freeze-drying. The raw components used in the fabrication of DTSCS and STSCS were separated and purified from tilapia fish skin. It is anticipated that these collagen sponges could be developed into medical dressings for hemostasis and wound healing. The aim of the present research was to explore the possibility of DTSCS and STSCS as medical dressings and compare their differences by scanning electron microscopy (SEM), water absorption measurement, differential scanning calorimetry (DSC), measurement of porosity, cytotoxicity, hemolysis, in vivo biocompatibility, and evaluation of hemostatic performance and wound healing. The results indicate that DTSCS and STSCS are suitable materials for use in medical applications with a loose and porous structure, high water absorption, high porosity, and high thermal stability. The materials also displayed good biocompatibility, including excellent blood compatibility, a lack of cytotoxicity, with no apparent rejection following implantation. STSCS exhibited rapid hemostasis and promoted healing, with slightly greater efficacy than DTSCS. The hemostatic properties and promotion of healing in DTSCS was similar to that of commercial bovine collagen sponge. Therefore, DTSCS and STSCS both represented excellent potential candidate materials for use as hemostatic agents and wound dressings.

Hybrid Bilayer PLA/Chitosan Nanofibrous Scaffolds Doped with ZnO, Fe3O4, and Au Nanoparticles with Bioactive Properties for Skin Tissue Engineering

Burns affect almost half a million of Americans annually. In the case of full-thickness skin injuries, treatment requires a transplant. The development of bioactive materials that promote damaged tissue regeneration constitutes a great alternative to autografts. For this reason, special attention is focused on three-dimensional scaffolds that are non-toxic to skin cells and can mimic the extracellular matrix, which is mainly composed of nanofibrous proteins. Electrospinning, which enables the preparation of nanofibers, is a powerful tool in the field of biomaterials. In this work, novel hybrid poly (lactic acid)/chitosan biomaterials functionalized with three types of nanoparticles (NPs) were successfully developed. ZnO, Fe3O4, and Au NPs were investigated over their morphology by TEM method. The top layer was obtained from PLA nanofibers, while the bottom layer was prepared from acylated chitosan. The layers were studied over their morphology by the SEM method and their chemical structure by FT-IR. To verify their potential in burn wound treatment, the scaffolds' susceptibility to biodegradation as well as moisture permeability were calculated. Also, biomaterials conductivity was determined in terms of electrostimulation. Finally, cytotoxicity tests were carried out by XTT assay and morphology analysis using both fibroblasts cell line and primary cells. The hybrid nanofibrous scaffolds displayed a great potential in tissue engineering.

The Characteristics of Intrinsic Fluorescence of Type I Collagen Influenced by Collagenase I

The triple helix structure of collagen can be degraded by collagenase. In this study, we explored how the intrinsic fluorescence of type I collagen was influenced by collagenase I. We found that tyrosine was the main factor that could successfully excite the collagen fluorescence. Initially, self-assembly behavior of collagen resulted in a large amount of tyrosine wrapped with collagen, which decreased the fluorescence intensity of type I collagen. After collagenase cleavage, some wrapped-tyrosine could be exposed and thereby the intrinsic fluorescence intensity of collagen increased. By observation and analysis, the influence of collagenase to intrinsic fluorescence of collagen was investigated and elaborated. Furthermore, collagenase cleavage to the special triple helix structure of collagen would result in a slight improvement of collagen thermostability, which was explained by the increasing amount of terminal peptides. These results are helpful and effective for reaction mechanism research related to collagen, which can be observed by fluorescent technology. Meantime, the reaction behaviors of both collagenase and collagenolytic proteases can also be analyzed by fluorescent technology. In conclusion, this research provides a foundation for the further investigation of collagen reactions in different areas, such as medicine, nutrition, food and agriculture.