Fibrin-Modified Cellulose as a Promising Dressing for Accelerated Wound Healing

Cellulose Acetate-Based Wound Dressings Loaded with Bioactive Agents: Potential Scaffolds for Wound Dressing and Skin Regeneration

Wound healing and skin regeneration are major challenges in chronic wounds. Among the types of wound dressing products currently available in the market, each wound dressing material is designed for a specific wound type. Some of these products suffer from various shortcomings, such as poor antibacterial efficacy and mechanical performance, inability to provide a moist environment, poor permeability to oxygen and capability to induce cell migration and proliferation during the wound healing process. Hydrogels and nanofibers are widely reported wound dressings that have demonstrated promising capability to overcome these shortcomings. Cellulose acetate is a semisynthetic polymer that has attracted great attention in the fabrication of hydrogels and nanofibers. Loading bioactive agents such as antibiotics, essential oils, metallic nanoparticles, plant extracts, and honey into cellulose acetate-based nanofibers and hydrogels enhanced their biological effects, including antibacterial, antioxidant, and wound healing. This review reports cellulose acetate-based hydrogels and nanofibers loaded with bioactive agents for wound dressing and skin regeneration.

Biomedical materials for wound dressing: recent advances and applications

Wound healing is vital to maintain the physiological functions of the skin. The most common treatment is the use of a dressing to cover the wound and reduce infection risk and the rate of secondary injuries. Modern wound dressings have been the top priority choice for healing various types of wounds owing to their outstanding biocompatibility and biodegradability. In addition, they also maintain temperature and a moist environment, aid in pain relief, and improve hypoxic environments to stimulate wound healing. Due to the different types of wounds, as well as the variety of advanced wound dressing products, this review will provide information on the clinical characteristics of the wound, the properties of common modern dressings, and the in vitro, in vivo as well as the clinical trials on their effectiveness. The most popular types commonly used in producing modern dressings are hydrogels, hydrocolloids, alginates, foams, and films. In addition, the review also presents the polymer materials for dressing applications as well as the trend of developing these current modern dressings to maximize their function and create ideal dressings. The last is the discussion about dressing selection in wound treatment and an estimate of the current development tendency of new materials for wound healing dressings.

New insights into balancing wound healing and scarless skin repair

Scars caused by skin injuries after burns, wounds, abrasions and operations have serious physical and psychological effects on patients. In recent years, the research of scar free wound repair has been greatly expanded. However, understanding the complex mechanisms of wound healing, in which various cells, cytokines and mechanical force interact, is critical to developing a treatment that can achieve scarless wound healing. Therefore, this paper reviews the types of wounds, the mechanism of scar formation in the healing process, and the current research progress on the dual consideration of wound healing and scar prevention, and some strategies for the treatment of scar free wound repair.

3D-printed high-density polyethylene scaffolds with bioactive and antibacterial layer-by-layer modification for auricle reconstruction

High-density polyethylene (HDPE) is a promising material for the development of scaffold implants for auricle reconstruction. However, preparing a personalized HDPE auricle implant with favorable bioactive and antibacterial functions to promote skin tissue ingrowth is challenging. Herein, we present 3D-printed HDPE auricle scaffolds with satisfactory pore size and connectivity. The layer-by-layer (LBL) approach was applied to achieve the improved bioactive and antibacterial properties of these 3D printed scaffolds. The HDPE auricle scaffolds were fabricated using an extrusion 3D printing approach, and the individualized macrostructure and porous microstructure were both adjusted by the 3D printing parameters. The polydopamine (pDA) coating method was used to construct a multilayer ε-polylysine (EPL) and fibrin (FIB) modification on the surface of the 3D HDPE scaffold via the LBL self-assembly approach, which provides the bioactive and antibacterial properties. The results of the in vivo experiments using an animal model showed that LBL-coated HDPE auricular scaffolds were able to significantly enhance skin tissue ingrowth and ameliorate the inflammatory response caused by local stress. The results of this study suggest that the combination of the 3D printing technique and surface modification provides a promising strategy for developing personalized implants with biofunctional coatings, which show great potential as a scaffold implant for auricle reconstruction applications.

Evaluating polymeric biomaterials to improve next generation wound dressing design

Wound healing is a dynamic series of interconnected events with the ultimate goal of promoting neotissue formation and restoration of anatomical function. Yet, the complexity of wound healing can often result in development of complex, chronic wounds, which currently results in a significant strain and burden to our healthcare system. The advancement of new and effective wound care therapies remains a critical issue, with the current therapeutic modalities often remaining inadequate. Notably, the field of tissue engineering has grown significantly in the last several years, in part, due to the diverse properties and applications of polymeric biomaterials. The interdisciplinary cohesion of the chemical, biological, physical, and material sciences is pertinent to advancing our current understanding of biomaterials and generating new wound care modalities. However, there is still room for closing the gap between the clinical and material science realms in order to more effectively develop novel wound care therapies that aid in the treatment of complex wounds. Thus, in this review, we discuss key material science principles in the context of polymeric biomaterials, provide a clinical breadth to discuss how these properties affect wound dressing design, and the role of polymeric biomaterials in the innovation and design of the next generation of wound dressings.

Production and application of biomaterials based on polyvinyl alcohol (PVA) as wound dressing: A mini review

The development of ideal wound dressing with excellent properties, such as exudate absorption capacity, drug release control ability, and increased wound healing, is currently a major requirement for wound healing. Polyvinyl alcohol (PVA) is a biodegradable semi-crystalline synthetic polymer that has been used in the field of biotechnology such as tissue regeneration, wound dressing, and drug delivery systems. In recent years, PVA-based wound dressing materials have received considerable attention due to their excellent properties such as biodegradability, biocompatibility, non-toxicity and low cost. PVA can be used as a wound dressing material to create the necessary moist wound environment, improve the physical properties of the dressing, and increase the wound healing rates. In addition, PVA can also be mixed with other organic and inorganic materials and can be used for drug delivery and wound healing. This review article addresses the role of biomaterials based on PVA mixed with other ingredients for wound dressing. It also focuses on its recent use in wound dressings as carriers of active substances.

Advances in Fibrin-Based Materials in Wound Repair: A Review

The first bioprocess that occurs in response to wounding is the deterrence of local hemorrhage. This is accomplished by platelet aggregation and initiation of the hemostasis cascade. The resulting blood clot immediately enables the cessation of bleeding and then functions as a provisional matrix for wound healing, which begins a few days after injury. Here, fibrinogen and fibrin fibers are the key players, because they literally serve as scaffolds for tissue regeneration and promote the migration of cells, as well as the ingrowth of tissues. Fibrin is also an important modulator of healing and a host defense system against microbes that effectively maintains incoming leukocytes and acts as reservoir for growth factors. This review presents recent advances in the understanding and applications of fibrin and fibrin-fiber-incorporated biomedical materials applied to wound healing and subsequent tissue repair. It also discusses how fibrin-based materials function through several wound healing stages including physical barrier formation, the entrapment of bacteria, drug and cell delivery, and eventual degradation. Pure fibrin is not mechanically strong and stable enough to act as a singular wound repair material. To alleviate this problem, this paper will demonstrate recent advances in the modification of fibrin with next-generation materials exhibiting enhanced stability and medical efficacy, along with a detailed look at the mechanical properties of fibrin and fibrin-laden materials. Specifically, fibrin-based nanocomposites and their role in wound repair, sustained drug release, cell delivery to wound sites, skin reconstruction, and biomedical applications of drug-loaded fibrin-based materials will be demonstrated and discussed.

Insight into Factors Influencing Wound Healing Using Phosphorylated Cellulose-Filled-Chitosan Nanocomposite Films

Marine polysaccharides are believed to be promising wound-dressing nanomaterials because of their biocompatibility, antibacterial and hemostatic activity, and ability to easily shape into transparent films, hydrogels, and porous foams that can provide a moist micro-environment and adsorb exudates. Current efforts are firmly focused on the preparation of novel polysaccharide-derived nanomaterials functionalized with chemical objects to meet the mechanical and biological requirements of ideal wound healing systems. In this contribution, we investigated the characteristics of six different cellulose-filled chitosan transparent films as potential factors that could help to accelerate wound healing. Both microcrystalline and nano-sized cellulose, as well as native and phosphorylated cellulose, were used as fillers to simultaneously elucidate the roles of size and functionalization. The assessment of their influences on hemostatic properties indicated that the tested nanocomposites shorten clotting times by affecting both the extrinsic and intrinsic pathways of the blood coagulation system. We also showed that all biocomposites have antioxidant capacity. Moreover, the cytotoxicity and genotoxicity of the materials against two cell lines, human BJ fibroblasts and human KERTr keratinocytes, was investigated. The nature of the cellulose used as a filler was found to influence their cytotoxicity at a relatively low level. Potential mechanisms of cytotoxicity were also investigated; only one (phosphorylated microcellulose-filled chitosan films) of the compounds tested produced reactive oxygen species (ROS) to a small extent, and some films reduced the level of ROS, probably due to their antioxidant properties. The transmembrane mitochondrial potential was very slightly lowered. These biocompatible films showed no genotoxicity, and very importantly for wound healing, most of them significantly accelerated migration of both fibroblasts and keratinocytes.

Cellulose Nanocrystal-Fibrin Nanocomposite Hydrogels Promoting Myotube Formation

Cellulose nanocrystals (CNCs) have been widely studied as fillers to form reinforced nanocomposites with a wide range of applications, including the biomedical field. Here, we evaluated the possibility to combine them with fibrinogen and obtain fibrin hydrogels with improved mechanical stability as potential cellular scaffolds. In diluted conditions at a neutral pH, it was evidenced that fibrinogen could adsorb on CNCs in a two-step process, favoring their alignment under flow. Composite hydrogels could be prepared from concentrated fibrinogen solutions and nanocrystals in amounts up to 0.3 wt %. CNCs induced a significant modification of the initial fibrin fibrillogenesis and final fibrin network structure, and storage moduli of all nanocomposites were larger than those of pure fibrin hydrogels. Moreover, optimal conditions were found that promoted muscle cell differentiation and formation of long myotubes. These results provide original insights into the interactions of CNCs with proteins with key physiological functions and offer new perspectives for the design of injectable fibrin-based formulations.

Development of Bacterial Cellulose Biocomposites Combined with Starch and Collagen and Evaluation of Their Properties

One of the major benefits of biomedicine is the use of biocomposites as wound dressings to help improve the treatment of injuries. Therefore, the main objective of this study was to develop and characterize biocomposites based on bacterial cellulose (BC) with different concentrations of collagen and starch and characterize their thermal, morphological, mechanical, physical, and barrier properties. In total, nine samples were produced with fixed amounts of glycerol and BC and variations in the amount of collagen and starch. The water activity (0.400–0.480), water solubility (12.94–69.7%), moisture (10.75–20.60%), thickness (0.04–0.11 mm), water vapor permeability (5.59–14.06 × 10⁻⁸ g·mm/m²·h·Pa), grammage (8.91–39.58 g·cm⁻²), opacity (8.37–36.67 Abs 600 nm·mm⁻¹), elongation (4.81–169.54%), and tensile strength (0.99–16.32 MPa) were evaluated and defined. In addition, scanning electron microscopy showed that adding biopolymers in the cellulose matrix made the surface compact, which also influenced the visual appearance. Thus, the performance of the biocomposites was directly influenced by their composition. The performance of the different samples obtained resulted in them having different potentials for application considering the injury type. This provides a solution for the ineffectiveness of traditional dressings, which is one of the great problems of the biomedical sector.

Architectural and Ultrastructural Variations of Human Leukocyte-Rich Platelet-Rich Fibrin and Injectable Platelet-Rich Fibrin

Background:

Platelet-rich fibrin (PRF) architecture and ultrastructure plays a crucial role in regulating and coordinating the cellular functions and provides a physical architecture, mechanical stability, and biochemical cues necessary for tissue morphogenesis and homeostasis. No study consciously reported the variation in architecture, ultrastructure, and morphology of leukocyte-rich PRF (L-PRF) and injectable PRF (i-PRF).

Objective:

Hence, the present study was aimed to evaluate the fibrin architecture, ultrastructure, and cell contents of autologous L-PRF and i-PRF.

Materials and Methods:

The autologous L-PRF and i-PRF were prepared from blood samples of healthy donors. The morphological and structural variations were assessed by histopathology, atomic force microscopy, confocal laser scanning microscope, and field emission scanning electron microscope.

Results:

Disparity was found on architecture and ultrastructure of L-PRF and i-PRF fibrin network. The variation in platelet and leukocyte concentration attributed to the fibrin conformational changes. L-PRF shows thick fibrins with rough surface, whereas in i-PRF, smooth thin fibrins.

Conclusions:

The current study revealed that there is heterogeneity between L-PRF and i-PRF fibrin matrix architecture, ultrastructure, platelets, leukocytes, and the fibrin content. These speculate that the diameter, width, roughness, and smoothness of fibrin fibers, pore size, and shapes of L-PRF and i-PRF matrix may initiate and mediate the scaffold functions differently.

Effects of Bacterial Nanocellulose Loaded with Curcumin and Its Degradation Products on Human Dermal Fibroblasts

Bacterial nanocellulose has found applications in tissue engineering, in skin tissue repair, and in wound healing. Its large surface area enables the adsorption of various substances. Bacterial nanocellulose with adsorbed substances can serve as a substrate for drug-delivery of specific bioactive healing agents into wounds. In this study, we loaded a bacterial nanocellulose hydrogel with curcumin, i.e., an important anti-bacterial and healing agent, and its degradation products. These products were prepared by thermal decomposition of curcumin (DC) at a temperature of 180 °C (DC 180) or of 300 °C (DC 300). The main thermal decomposition products were tumerone, vanillin, and feruloylmethane. Curcumin and its degradation products were loaded into the bacterial nanocellulose by an autoclaving process. The increased temperature during autoclaving enhanced the solubility and the penetration of the agents into the nanocellulose. The aim of this study was to investigate the cytotoxicity and the antimicrobial activity of pure curcumin, its degradation products, and finally of bacterial nanocellulose loaded with these agents. In vitro tests performed on human dermal fibroblasts revealed that the degradation products of curcumin, i.e., DC 180 and DC 300, were more cytotoxic than pure curcumin. However, if DC 300 was loaded into nanocellulose, the cytotoxic effect was not as strong as in the case of DC 300 powder added into the culture medium. DC 300 was found to be the least soluble product in water, which probably resulted in the poor loading of this agent into the nanocellulose. Nanocellulose loaded with pure curcumin or DC 180 exhibited more antibacterial activity than pristine nanocellulose.

Carboxymethyl cellulose-based materials for infection control and wound healing: A review

The development of ideal wound dressing materials with excellent characteristics is currently a major demand in wound therapy. In recent years, carboxymethyl cellulose (CMC)-based wound dressing materials have been of immense attraction due to their noble properties, such as: biocompatibility, biodegradability, tissue resembling, low cost and non-toxic. It is used extensively, in a variety of applications in the biomedical and pharmaceutical fields. The hydrophilic nature of CMC, makes it possible to blend and cross-link with other materials, such as: synthetic polymers, natural polymers and inorganic materials and it enables the preparation of innovative wound dressing biomaterials. Hence, this review, focuses on the intrinsic characteristics of CMC-based wound dressing materials, including hydrogels, films, 3D printing, fibres, gauzes and their recent advancements in chronic wound healing.

Autologous Matrix of Platelet-Rich Fibrin in Wound Care Settings: A Systematic Review of Randomized Clinical Trials

Platelet-rich fibrin (PRF) consists of a matrix that provides the necessary elements for wound healing, acting as a biodegradable scaffold for cell migration, proliferation, and differentiation, in addition to the delivery of growth factors and angiogenesis. This study aims to determine the effectiveness of the autologous PRF in the treatment of wounds of different etiologies. We carried out a systematic review of randomized clinical trials, guided by the recommendations of the Cochrane Collaboration using the following databases: Pubmed/MEDLINE, EMBASE, Web of Science, and CENTRAL. The search strategy resulted in the inclusion of ten studies that evaluated the use of PRF dressings for the healing of acute or chronic wounds of multiple etiologies. Among the 172 participants treated with PRF in wounds of varying etiologies and different segment times, 130 presented favorable events with the use of the intervention. Among the 10 studies included, only two of them did not demonstrate better results than the control group. The studies showed clinical heterogeneity, making it impossible to perform a meta-analysis. The findings do not provide enough evidence to support the routine use of PRF dressings as the first line of treatment for the healing of acute or chronic wounds of different etiologies. There was great variability in the application of the various protocols and the ways to prepare the PRF, resulting in clinical heterogeneity. Therefore, it makes it impossible to synthesize and to collect evidence from different types of studies in the meta-analysis, which affects the results and their proper discussion.

Versatile Application of Nanocellulose: From Industry to Skin Tissue Engineering and Wound Healing

Nanocellulose is cellulose in the form of nanostructures, i.e., features not exceeding 100 nm at least in one dimension. These nanostructures include nanofibrils, found in bacterial cellulose; nanofibers, present particularly in electrospun matrices; and nanowhiskers, nanocrystals, nanorods, and nanoballs. These structures can be further assembled into bigger two-dimensional (2D) and three-dimensional (3D) nano-, micro-, and macro-structures, such as nanoplatelets, membranes, films, microparticles, and porous macroscopic matrices. There are four main sources of nanocellulose: bacteria (Gluconacetobacter), plants (trees, shrubs, herbs), algae (Cladophora), and animals (Tunicata). Nanocellulose has emerged for a wide range of industrial, technology, and biomedical applications, namely for adsorption, ultrafiltration, packaging, conservation of historical artifacts, thermal insulation and fire retardation, energy extraction and storage, acoustics, sensorics, controlled drug delivery, and particularly for tissue engineering. Nanocellulose is promising for use in scaffolds for engineering of blood vessels, neural tissue, bone, cartilage, liver, adipose tissue, urethra and dura mater, for repairing connective tissue and congenital heart defects, and for constructing contact lenses and protective barriers. This review is focused on applications of nanocellulose in skin tissue engineering and wound healing as a scaffold for cell growth, for delivering cells into wounds, and as a material for advanced wound dressings coupled with drug delivery, transparency and sensorics. Potential cytotoxicity and immunogenicity of nanocellulose are also discussed.