In vitro and in vivo evaluation of effectiveness of a novel TEMPO-oxidized cellulose nanofiber-silk fibroin scaffold in wound healing

ECM derivatized alginate augmenting bio-functionalities of lyophilized mat for skin and liver wound treatment

Peptides and molecular residues sourced from the fragmentation of the extracellular matrix (ECM) can exacerbate a plethora of cellular functions. We selected a natural ECM-derived complex peptide mixture to functionalize sodium alginate. Three alginate derivatives (sodium alginate conjugated with ECM) SALE-1, SALE-2, and SALE-3 were synthesized using the lowest (10 % w/w), moderate (50 % w/w), and highest (100 % w/w) concentrations of ECM. Thereafter, they were used to fabricate three groups of mat scaffolds EMAT-1 (ECM derivatized alginate thrombin-mat), EMAT-2, and EMAT-3, respectively by the freeze-drying process. To enhance the hemostatic activity, thrombin was loaded onto the scaffolds. Another group, AT, without any derivatized alginate was additionally included in order to comparative analysis. Physical characteristics revealed that the porous mat scaffold showed enhancement in degradation and swelling ability with the increase in ECM content. The higher cell proliferation, migration, and cell viability were noticed in the higher ECM-containing samples EMAT-2 and EMAT-3. In vivo studies using rodent hepatic and rabbit ear models were carried out to ensure the hemostatic ability of the scaffolds. EMAT-2 and EMAT-3 demonstrate excellent liver regeneration ability in rat models. Moreover, the rat cutaneous wound model depicted that EMAT-3 dramatically elevated the skin's healing ability, thereby rendering it an excellent candidate for future clinical application in wound healing.

The role of phlorizin liposome-embedded oxidized sodium alginate/carboxymethyl chitosan in diabetic wound healing

Wound healing in diabetic patients is often complicated by issues like inflammation, infection, bleeding, and fluid retention. To tackle these challenges, it is essential to create hydrogel dressings with anti-inflammatory, antibacterial, and antioxidative properties. This study aimed to synthesize Phlorizin-Liposomes (PL) through the thin-film dispersion method and integrate them into an oxidized sodium alginate (OSA) and carboxymethyl chitosan (CMCS) hydrogel scaffold, resulting in an OSA/CMCS/PL (PLOCS) composite hydrogel via a Schiff base reaction. Characterization of the composite was performed using FTIR, TEM, and SEM techniques. The research assessed the swelling behavior, antibacterial effectiveness, and biocompatibility of the PLOCS composite hydrogel, while also investigating how PLOCS facilitates diabetic wound healing. The results demonstrated that PLOCS effectively controls drug release, possesses favorable swelling and degradation characteristics, and shows significant antioxidative properties along with in vitro biocompatibility. Histological analysis confirmed that PLOCS supports the proliferation of healthy epithelial tissue and collagen production. Western blotting indicated that PLOCS diminishes inflammation by inhibiting the TLR4/NF-κB/MyD88 pathway and activates Nrf2 to boost wound healing, increasing the levels of antioxidative enzymes such as HO-1, NQO1, and GCLC. In summary, PLOCS presents a promising new option for advanced wound dressings aimed at treating diabetic ulcers.

Cellulose as a sustainable scaffold material in cultivated meat production

The rapid progress in cultivated meat research has engendered considerable attention towards the edible scaffolding biomaterials employed in the production. Cellulose has the advantages in availability, edibility, animal-free origin, etc., which show its potential in wide fields. This review begins by presenting the fundamental physical and chemical properties of cellulose from different sources, including plant and bacterial cellulose. Subsequently, we summarize the application of cellulose especially in cultivated meat and tissue engineering. Furthermore, we explore various methods for preparing cellulose-based scaffolds for cultivated meat, encompassing five specific structural variations. In the end, associated with utilizing cellulose in cultivated meat production, we address several primary challenges surrounding to cell adhesion, scaling up, processibility and mechanical properties, and provide potential innovations. This review underscores the potential of cellulose as a versatile biomaterial in the cultivated meat industry and provides insight into addressing critical challenges for its integration.

The Application of Regenerated Silk Fibroin in Tissue Repair

Silk fibroin (SF) extracted from silk is non-toxic and has excellent biocompatibility and biodegradability, making it an excellent biomedical material. SF-based soft materials, including porous scaffolds and hydrogels, play an important role in accurately delivering drugs to wounds, creating microenvironments for the adhesion and proliferation of support cells, and in tissue remodeling, repair, and wound healing. This article focuses on the study of SF protein-based soft materials, summarizing their preparation methods and basic applications, as well as their regenerative effects, such as drug delivery carriers in various aspects of tissue engineering such as bone, blood vessels, nerves, and skin in recent years, as well as their promoting effects on wound healing and repair processes. The authors expect SF soft materials to play an important role in the field of tissue repair.

Antibacterial and antioxidant phlorizin-loaded nanofiber film effectively promotes the healing of burn wounds

Burns usually result in damage and loss of skin forming irregular wound wounds. The lack of skin tissue protection makes the wound site highly vulnerable to bacterial infections, hindering the healing process. However, commonly used wound dressings do not readily provide complete coverage of irregular wounds compared to regular wounds. Therefore, there is an urgent need to prepare a wound dressing with high antimicrobial efficacy for the administration of drugs to irregular wounds. In this study, a chitosan (CS)/polyvinylpyrrolidone (PVP) composite nanofiber membrane (CS/PVP/Phlorizin) loaded with root bark glycosides (Phlorizin) was developed using an electrostatic spinning technique. The incorporation of phlorizin, a natural antioxidant, into the fiber membranes notably boosted their antimicrobial and antioxidant capabilities, along with demonstrating excellent hydrophilic characteristics. In vitro cellular experiments showed that CS/PVP/Phlorizin increased Hacat cell viability with the presence of better cytocompatibility. In scald wound healing experiments, Phlorizin-loaded nanofibrous membranes significantly promoted re-epithelialization and angiogenesis at the wound site, and reduced the inflammatory response at the wound site. Therefore, the above results indicate that this nanofiber membrane is expected to be an ideal dressing for burn wounds.

Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review

Wound healing can result in complex problems, and discovering an effective method to improve the healing process is essential. Polymeric biomaterials have structures similar to those identified in the extracellular matrix of the tissue to be regenerated and also avoid chronic inflammation, and immunological reactions. To obtain smart and effective dressings, bioactive agents, such as essential oils, are also used to promote a wide range of biological properties, which can accelerate the healing process. Therefore, we intend to explore advances in the potential for applying hybrid materials in wound healing. For this, fifty scientific articles dated from 2010 to 2023 were investigated using the Web of Science, Scopus, Science Direct, and PubMed databases. The principles of the healing process, use of polymers, type and properties of essential oils and processing techniques, and characteristics of dressings were identified. Thus, the plants Syzygium romanticum or Eugenia caryophyllata, Origanum vulgare, and Cinnamomum zeylanicum present prospects for application in clinical trials due to their proven effects on wound healing and reducing the incidence of inflammatory cells in the site of injury. The antimicrobial effect of essential oils is mainly due to polyphenols and terpenes such as eugenol, cinnamaldehyde, carvacrol, and thymol.

Dual cross-linked self-healing hydrogel enhanced by dopamine nanoparticles and raffinose for wound healing

A series of intricate and dynamic physiological healing processes are involved in the healing of skin wounds. Herein, a multifunctional hydrogel is firstly designed and constructed by L-arginine-grafted O-carboxymethyl chitosan (CMCA), catechol-modified oxidized hyaluronic acid (DOHA), and dopamine nanoparticles (pDA-NPs). pDA-NPs were loaded in hydrogel for inherently powerful antimicrobial properties and could be as a cross-linking agent to construct hydrogels. Raffinose (Raf) was further incorporated to obtain CMCA-DOHA-pDA2@Raf hydrogel for its function of modulating epidermal differentiation. The hydrogel has good physicochemical properties and could promote cell proliferation and migration, which shows superior hemostatic capabilities in animal models of hemorrhage. The hydrogel significantly promoted wound healing on rat skin defect models by upregulating VEGF and CD31 and decreasing IL-6 and TNF-α, stimulating neovascularization and collagen deposition in epithelial structures. This multifunctional hydrogel implies the potential to be a dynamic wound dressing.

Controlling the Magnetic Responsiveness of Cellulose Nanofiber Particles Embedded with Iron Oxide Nanoparticles

2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofiber (TOCN) particles, an innovative biobased material derived from wood biomass, have garnered significant interest, particularly in the biomedical field, for their distinctive properties as biocompatible particle adsorbents. However, their microscopic size complicates their separation in liquid media, thereby impeding their application in various domains. In this study, superparamagnetic magnetite nanoparticles (NPs), specifically iron oxide Fe3O4 NPs with an average size of 15 nm, were used to enhance the collection efficiency of TOCN-Fe3O4 composite particles synthesized through spray drying. These composite particles exhibited a remarkable ζ-potential (approximately -50 mV), indicating their high stability in water, as well as impressive magnetization properties (up to 47 emu/g), and rapid magnetic responsiveness within 60 s in water (3 wt % Fe3O4 to TOCN, 1 T magnet). Furthermore, the influence of Fe3O4 NP concentrations on the measurement of the speed of magnetic separation was quantitatively discussed. Additionally, the binding affinity of the synthesized particles for proteins was assessed on a streptavidin-biotin binding system, offering crucial insights into their binding capabilities with specific proteins and underscoring their significant potential as functionalized biomedical materials.

pH-Responsive Cellulose/Silk/Fe3O4 Hydrogel Microbeads Designed for Biomedical Applications

In this study, cellulose/Fe3O4 hydrogel microbeads were prepared through the sol-gel transition of a solvent-in-oil emulsion using various cellulose-dissolving solvents and soybean oil without surfactants. Particularly, 40% tetrabutylammonium hydroxide (TBAH) and 40% tetrabutylphosphonium hydroxide (TBPH) dissolved cellulose at room temperature and effectively dispersed Fe3O4, forming cellulose/Fe3O4 microbeads with an average diameter of ~15 µm. Additionally, these solvents co-dissolved cellulose and silk, allowing for the manufacture of cellulose/silk/Fe3O4 hydrogel microbeads with altered surface characteristics. Owing to the negatively charged surface characteristics, the adsorption capacity of the cellulose/silk/Fe3O4 microbeads for the cationic dye crystal violet was >10 times higher than that of the cellulose/Fe3O4 microbeads. When prepared with TBAH, the initial adsorption rate of bovine serum albumin (BSA) on the cellulose/silk/Fe3O4 microbeads was 18.1 times higher than that on the cellulose/Fe3O4 microbeads. When preparing TBPH, the equilibrium adsorption capacity of the cellulose/silk/Fe3O4 microbeads for BSA (1.6 g/g) was 8.5 times higher than that of the cellulose/Fe3O4 microbeads. The pH-dependent BSA release from the cellulose/silk/Fe3O4 microbeads prepared with TBPH revealed 6.1-fold slower initial desorption rates and 5.2-fold lower desorption amounts at pH 2.2 than those at pH 7.4. Cytotoxicity tests on the cellulose and cellulose/silk composites regenerated with TBAH and TBPH yielded nontoxic results. Therefore, cellulose/silk/Fe3O4 microbeads are considered suitable pH-responsive supports for orally administered protein pharmaceuticals.

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.

Unconventional luminescent CS-PEC-based composite hemostasis sponge with antibacterial activity and visual monitoring for wound healing

Multifunctional wound dressings are promising medical materials for various applications. Among them, dressings with antimicrobial activity, high biosafety, and real-time monitoring have attracted considerable research interest. Herein, a biodegradable hemostatic sponge comprising a chitosan skeleton and polyelectrolyte-surfactant complex (CS-PEC) was developed as a versatile wound dressing for wound pH monitoring and inhibition of bacterial infection. CS-PEC sponge with high porosity exhibited satisfactory fluid absorption capacity and biocompatibility, along with antibacterial properties against E. coli and S. aureus. In vivo experiments in rat liver trauma model revealed that wounds treated with the CS-PEC sponge recorded less blood loss (97.1 mg) and shorter hemostasis time (27.2 s) than those treated with commercial gelatin sponge (309.1 mg and 163.5 s, respectively). Furthermore, PECs based on unconventional luminescent molecules (L-C16-Hyp) were used as pH fluorescent indicators, which endowed the sponge with fluorescence-responsive behavior to wound pH changes in the range of 5.0-8.5. Visual images can be captured using a smartphone and converted to RGB color mode values for on-site assessment of wound status. This study sheds light on the design and application of unconventional luminescent materials in wound dressing and provides a smart and effective solution for wound management.

Polyphosphate-loaded silk fibroin membrane as hemostatic agent in oral surgery: a pilot study

PURPOSE

Post-interventional hemorrhage can result in serious complications, especially in patients with hemostatic disorders. Identification of safe and efficient local hemostatic agents is important, particularly in the context of an ageing society and the emergence of new oral anticoagulants. The aim of this in vitro study was to investigate the potential of silk fibroin membranes coated with the inorganic polymer polyphosphate (polyP) as a novel hemostatic device in oral surgery.

METHODS

Cocoons of the silkworm Bombyx mori were degummed and dissolved. Varying amounts of long-chain polyP (2-2000 µg/mm2) were adsorbed to the surface of silk fibroin membranes. Analysis of the procoagulant effect of polyP-coated silk membranes was performed using real-time thrombin generation assays in human plasma. Increasing concentrations of polyP (0.15-500 µg/ml) served as a positive control, while uncoated silk fibroin membranes were used as negative control.

RESULTS

PolyP-coated silk fibroin membranes triggered coagulation when compared to plasma samples and pure silk fibroin membranes. A polyP-dose-dependent effect of thrombin generation could be found with a maximum (ETP = 1525.7 nM⋅min, peak thrombin = 310.1 nM, time to peak = 9.8 min, lag time = 7.6 min.) at 200 µg/mm2 of polymer loading on the silk fibroin membrane surface.

CONCLUSIONS

In this study, it was demonstrated that silk fibroin membranes coated with polyP have the potential to act as a promising novel hemostatic device.

Role of inorganic ions in wound healing: an insight into the various approaches for localized delivery

Recently, the role of inorganic ions has been explored for its wound-healing applications. Ions do play key role in the normal functioning of the skin, including the epidermal barrier property, maintaining redox balance, enzymatic activities, tissue remodeling, etc. The care of chronic wounds is a concern and new cost-effective therapeutic strategies that modulate the wound microenvironment and cell behaviour are needed. First, this review illustrates the ions that play a role in wound healing and their molecular mechanisms that are accountable for modifying the wound. Further, the emerging strategies using metal ions to modulate the healing will be discussed. In this direction, localized delivery of inorganic ions of importance using advanced wound care biomaterials for wound healing applications is discussed.

Current advances of nanocellulose application in biomedical field

Nanocellulose (NC) is a natural fiber that can be extracted in fibrils or crystals form from different natural sources, including plants, bacteria, and algae. In recent years, nanocellulose has emerged as a sustainable biomaterial for various medicinal applications including drug delivery systems, wound healing, tissue engineering, and antimicrobial treatment due to its biocompatibility, low cytotoxicity, and exceptional water holding capacity for cell immobilization. Many antimicrobial products can be produced due to the chemical functionality of nanocellulose, such disposable antibacterial smart masks for healthcare use. This article discusses comprehensively three types of nanocellulose: cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and bacterial nanocellulose (BNC) in view of their structural and functional properties, extraction methods, and the distinctive biomedical applications based on the recently published work. On top of that, the biosafety profile and the future perspectives of nanocellulose-based biomaterials have been further discussed in this review.

Polysaccharide-based (kappa carrageenan/carboxymethyl chitosan) nanofibrous membrane loaded with antifibrinolytic drug for rapid hemostasis- in vitro and in vivo evaluation

This work aimed to establish a novel membrane consisting of hemostatic polysaccharides, kappa-carrageenan (KC), and carboxymethyl chitosan (CMC) in tandem with polyvinyl alcohol that spun together as a matrix and loaded with tranexamic acid (TXA) as antifibrinolytic agent for further coagulation effect during and after oral surgeries. The electrospinning of KC was done for the first time and in comparison of CMC has better hemostatic efficacy. The effect of the hemostat was investigated by its surface morphology (SEM), FTIR/ATR analysis, swelling behavior in both PBS and blood, hydrophilicity, porosity, mechanical properties, and cumulative release rate. The effect of materials and the drug concentration ratio were considered. The effect of acetic acid percent in aqueous solutions of CMC/PVA and KC/PVA on morphology was investigated. The cell culture assay showed that all membranes interacted well (98 %) with fibroblast cells attached and grown on the fabricated substrate. Furthermore, the membranes are evaluated by clotting time, whole blood clotting, hemocompatibility, and platelet and RBC adhesion tests. Also, the hemostatic performance of the membrane was analyzed in vivo, using the tail and liver bleeding model in rats. Therefore, TXA loading into CMC and KC dressing could be an attractive hemostatic system for various clinical applications.

Natural TEMPO oxidized cellulose nano fiber/alginate/dSECM hybrid aerogel with improved wound healing and hemostatic ability

Natural biopolymers have attracted considerable attention in a variety of biomedical applications. Herein, tempo-oxidized-cellulose nanofibers (T) were incorporated into sodium alginate/chitosan (A/C) to reinforce the physicochemical properties and further modified with decellularized skin extracellular matrix (E). A unique ACTE aerogel was successfully prepared, and its nontoxic behavior was validated using mouse fibroblast L929 cells. In vitro hemolysis results revealed excellent platelet adhesion and fibrin network formation abilities of the obtained aerogel. A high speed of homeostasis was attained based on the quick clotting in <60 s. Skin regeneration in vivo experiments were conducted using the ACT1E0 and ACT1E10 groups. In comparison to ACT1E0 samples, ACT1E10 samples demonstrated enhanced skin wound healing with increased neo-epithelialization, increased collagen deposition, and extracellular matrix remodeling. ACT1E10 was found to be a promising aerogel for skin defect regeneration due to its improved wound-healing ability.

Self-Assembly of Nanocellulose Hydrogels Mimicking Bacterial Cellulose for Wound Dressing Applications

The self-assembly of nanocellulose in the form of cellulose nanofibers (CNFs) can be accomplished via hydrogen-bonding assistance into completely bio-based hydrogels. This study aimed to use the intrinsic properties of CNFs, such as their ability to form strong networks and high absorption capacity and exploit them in the sustainable development of effective wound dressing materials. First, TEMPO-oxidized CNFs were separated directly from wood (W-CNFs) and compared with CNFs separated from wood pulp (P-CNFs). Second, two approaches were evaluated for hydrogel self-assembly from W-CNFs, where water was removed from the suspensions via evaporation through suspension casting (SC) or vacuum-assisted filtration (VF). Third, the W-CNF-VF hydrogel was compared to commercial bacterial cellulose (BC). The study demonstrates that the self-assembly via VF of nanocellulose hydrogels from wood was the most promising material as wound dressing and displayed comparable properties to that of BC and strength to that of soft tissue.

Exploring Supramolecular Interactions between the Extracellular-Matrix-Derived Minimalist Bioactive Peptide and Nanofibrillar Cellulose for the Development of an Advanced Biomolecular Scaffold

It has been increasingly evident over the last few years that bioactive peptide hydrogels in conjugation with polymer hydrogels are emerging as a new class of supramolecular materials suitable for various biomedical applications owing to their specificity, tunability, and nontoxicity toward the biological system. Despite their unique biocompatible features, both polymer- and peptide-based scaffolds suffer from certain limitations, which restrict their use toward developing efficient matrices for controlling cellular behavior. The peptide hydrogels usually form soft matrices with low mechanical strength, whereas most of the polymer hydrogels lack biofunctionality. In this direction, combining polymers with peptides to develop a conjugate hydrogel can be explored as an emergent approach to overcome the limitations of the individual components. The polymer will provide high mechanical strength, whereas the biofunctionality of the material can be induced by the bioactive peptide sequence. In this study, we utilized TEMPO-oxidized nanofibrillar cellulose as the polymer counterpart, which was co-assembled with a short N-cadherin mimetic bioactive peptide sequence, Nap-HAVDI, to fabricate an NFC-peptide conjugate hydrogel. Interestingly, the mechanical strength of the peptide hydrogel was found to be significantly improved by combining the peptide with the NFC in the conjugate hydrogel. The addition of the peptide into the NFC also reduced the pore size within NFC matrices, which further helped in improving cellular adhesion, survival, and proliferation. Furthermore, the cells grown on the NFC and NFC-peptide hybrid hydrogel demonstrated normal expression of cytoskeleton proteins, i.e., β-tubulin in C6 cells and actin in L929 cells, respectively. The selective response of neuronal cells toward the specific bioactive peptide was further observed through a protein expression study. Thus, our study demonstrated the collective role of the cellulose-peptide composite material that revealed superior physical properties and biological response of this composite scaffold, which may open up a new platform for biomedical applications.

A fabricated hydrogel of hyaluronic acid/curcumin shows super-activity to heal the bacterial infected wound

High risk of acute morbidities and even mortality from expanding the antibiotics resistant infectious wounds force indefinite efforts for development of high performance wound-healing materials. Herein, we design a procedure to fabricate a hyaluronic acid (HA)-based hydrogel to conjugate curcumin (Gel-H.P.Cur). The highlight of this work is to provide a favorite condition for capturing curcumin while protecting its structure and intensifying its activities because of the synchronization with HA. Accordingly, HA as a major component of dermis with a critical role in establishing skin health, could fortify the wound healing property as well as antibacterial activity of the hydrogel. Gel-H.P.Cur showed antibacterial properties against Pseudomonas aeruginosa (P. aeruginosa), which were examined by bactericidal efficiency, disk diffusion, anti-biofilm, and pyocyanin production assays. The effects of Gel-H.P.Cur on the inhibition of quorum sensing (QS) regulatory genes that contribute to expanding bacteria in the injured place was also significant. In addition, Gel-H.P.Cur showed high potential to heal the cutaneous wounds on the mouse excisional wound model with repairing histopathological damages rapidly and without scar. Taken together, the results strongly support Gel-H.P.Cur as a multipotent biomaterial for medical applications regarding the treatment of chronic, infected, and dehiscent wounds.

Cationic cellulose nanocrystals as sustainable green material for multi biological applications via ξ potential

The present study aims to disclose the activity of cationic cellulose nanocrystals (CNCs) as a promising multifunctional green nanomaterial with applications in biological aspects. The basic reason behind multifunctional behavior is zeta potential and size distribution of nano biopolymers; exhibit a remarkable physical and biological activity compared to normal molecules.The preliminary characterized studied using absorption spectral analysis showed strong absorption peak indicating that spectrum curves can be screen by UV spectra at wavelength range 200-400nm. Ultrastructural studies (SEM-EDS and TEM), manifest that CNCs are elliptical particles in shape. Also, TEM show CNCs are the ideal illustration of zero-dimensional (0-D) NPs, less than 5.1 nm in diameter with Cationic charge and similar results in size distribution by TEM. Nonetheless, developed as antioxidant activity IC₅₀ was 1467 ± 25.9 µg/mL, antimicrobial activity tested G^-ve strains, but not affected on tested G^+ve strains and tested fungi. Evaluating toxicity effect of cationic CNCs against human blood erythrocytes (RBCs) and Lymphocyte Proliferation and the end point evaluate by comet assay, which proven no cytotoxic effect. Also, a high dose 500 µg/mL of CNCs highly significant (p < 0.05) reduction in cell viability of Caco-2 cancer cells after 24 h. incubation time, whereas the IC₅₀ was 1884 ± 19.46 µg/mL. Moreover, genotoxic assay indicates Caco-2 cells cause apoptosis with no fragmentation in DNA. Undoubtedly, the obtained results brought about by the interaction of layers carrying opposing charges. Additionally, there is a balance between hydrophilic contact and electrostatic attraction. That emphasizes how the cationic CNCs have excellent potential for use as antioxidants, antimicrobials, and anticancer agents.

Wound dressing based on PVA nanofiber containing silk fibroin modified with GO/ZnO nanoparticles for superficial wound healing: In vitro and in vivo evaluations

Silk fibroin (SF), extracted from Bombyx mori, has unique physicochemical properties to achieve an efficient wound dressing. In this study, reduced graphene oxide (RGO)/ZnO NPs/silk fibroin nanocomposite was made, and an innovative nanofiber of SF/polyvinyl alcohol (PVA)/RGO/ZnO NPs was ready with the electrospinning technique and successfully characterized. The results of MIC and OD analyses were used to investigate the synthesized materials' antibacterial effects and displayed that the synthesized materials could inhibit growth against Staphylococcus aureus and Escherichia coli bacteria. However, both in vitro cytotoxicity (MTT) and scratch wound studies have shown that RGO/ZnO NPs and SF/PVA/RGO/ZnO NPs are not only non-toxic to NIH 3T3 fibroblasts, but also can cause cell viability, cell proliferation, and cell migration. Furthermore, improving the synthesized nanofiber's structural properties in the presence of RGO and ZnO NPs has been confirmed by performing tensile strength, contact angle, and biodegradation analyses. Also, in a cell attachment analysis, fibroblast cells had migrated and expanded well in the nanofibrous structures. Moreover, in vivo assay, SF/PVA/RGO/ZnO NPs nanofiber treated rats and has been shown significant healing activity and tissue regeneration compared with other treated groups. Therefore, this study suggests that SF/PVA/RGO/ZnO NPs nanofiber is a hopeful wound dressing for preventing bacteria growth and improving superficial wound repair.

Physico-biological evaluation of 3D printed dECM/TOCN/alginate hydrogel based scaffolds for cartilage tissue regeneration

Cartilage damage is the leading cause of osteoarthritis (OA), especially in an aging society. Mimicking the native cartilage microenvironment for chondrogenic differentiation along with constructing a stable and controlled architectural scaffold is considerably challenging. In this study, three-dimensional (3D) printed scaffolds using tempo-oxidized cellulose nanofiber (TOCN), decellularized extracellular matrix (dECM), and sodium alginate (SA) were fabricated for cartilage tissue regeneration. We prepared three groups (dECM80, dECM50, dECM20) of 3D printable hydrogels with different ratios of TOCN and dECM where SA concentration remained the same. Two-step crosslinking was performed with CaCl₂ solution to achieve the highly stable 3D printed scaffolds. Finally, the fundamental physical characterizations showed that increasing the ratio of TOCN with dECM significantly improved the viscoelastic behaviour, stability, mechanical properties, and printability of the scaffolds. Based on the results, the 3D printed dECM50 scaffolds with controlled and identical pore sizes increased the whole-layer integrity and nutrient supply in each layer of the scaffold. Furthermore, evaluation of in vitro and in vivo biocompatibility of the scaffolds with rBMSCs indicated that dECM50 scaffolds provided a suitable microenvironment for cell proliferation and promoted chondrogenesis by remarkably expressing the cartilage-specific markers. This study demonstrates that 3D printed dECM50 scaffolds provide a favourable and promising microenvironment for cartilage tissue regeneration.

Nanomaterials supported by polymers for tissue engineering applications: A review

In the biomedical sciences, particularly in wound healing, tissue engineering, and regenerative medicine, the development of natural-based biomaterials as a carrier has revealed a wide range of advantages. Tissue engineering is one of the therapeutic approaches used to replace damaged tissue. Polymers have received a lot of attention for their beneficial interactions with cells, but they have some drawbacks, such as poor mechanical properties. Due to their relatively large surface area, nanoparticles can cause significant changes in polymers and improve their mechanical properties. The nanoparticles incorporated into biomaterial scaffolds have been associated with positive effects on cell adhesion, viability, proliferation, and migration in the majority of studies. This review paper discusses recent applications of polymer-nanoparticle composites in the development of tissue engineering scaffolds, as well as the effects of these nanomaterials in the fields of cardiovascular, neural, bone, and skin tissue engineering.

Influence of Cedar Essential Oil on Physical and Biological Properties of Hemostatic, Antibacterial, and Antioxidant Polyvinyl Alcohol/Cedar Oil/Kaolin Composite Hydrogels

Polyvinyl alcohol (PVA) is a safe and biodegradable polymer. Given the unique physical and chemical properties of PVA, we physically cross-linked PVA with kaolin (K) and cedar essential oil (Ced) using the freeze-thawing approach to fabricate PVA/Ced/K sponge hydrogels as hemostatic, antibacterial, and antioxidant wound healing materials. The physicochemical characteristics of PVA/Ced/K hydrogels, including water swelling profiles and gel fractions, were surveyed. Additionally, the functional groups of hydrogels were explored by Fourier transform infrared spectroscopy (FTIR), while their microstructures were studied using scanning electron microscopy (SEM). Furthermore, the thermal features of the hydrogels were probed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Evidently, alterations in cedar concentrations resulted in significant variations in size, water uptake profiles, and hydrolytic degradation of the hydrogels. The incorporation of cedar into the PVA/K endowed the hydrogels with significantly improved antibacterial competency against Bacillus cereus (B. cereus) and Escherichia coli (E. coli). Moreover, PVA/Ced/K exhibited high scavenging capacities toward ABTS•+ and DPPH free radicals. Beyond that, PVA/Ced/K hydrogels demonstrated hemocompatibility and fast blood clotting performance in addition to biocompatibility toward fibroblasts. These findings accentuate the prospective implementation of PVA/Ced/K composite hydrogel as a wound dressing.

Nanobiotechnology: Applications in Chronic Wound Healing

Wounds occur when skin integrity is broken and the skin is damaged. With progressive changes in the disease spectrum, the acute wounds caused by mechanical trauma have been become less common, while chronic wounds triggered with aging, diabetes and infection have become more frequent. Chronic wounds now affect more than 6 million people in the United States, amounting to 10 billion dollars in annual expenditure. However, the treatment of chronic wounds is associated with numerous challenges. Traditional remedies for chronic wounds include skin grafting, flap transplantation, negative-pressure wound therapy, and gauze dressing, all of which can cause tissue damage or activity limitations. Nanobiotechnology — which comprises a diverse array of technologies derived from engineering, chemistry, and biology — is now being applied in biomedical practice. Here, we review the design, application, and clinical trials for nanotechnology-based therapies for chronic wound healing, highlighting the clinical potential of nanobiotechnology in such treatments. By summarizing previous nanobiotechnology studies, we lay the foundation for future wound care via a nanotech-based multifunctional smart system.

SF/PVP nanofiber wound dressings loaded with phlorizin: preparation, characterization, in vivo and in vitro evaluation

Electrospinning-based wound dressings have multiple functions such as antibacterial, anti-inflammatory, and therapeutic, and are important in skin wound care. Herein, we designed a phlorizin (PHL)-loaded silk protein/polyvinylpyrrolidone (SF/PVP) composite nanofibrous membrane, which can be used as multiple wound dressings. In particular, SF/PVP/PHL scaffolds have high porosity and mechanical properties, exhibiting suitable permeability and hydrophilicity. The SF/PVP/PHL scaffolds containing PHL also have excellent antibacterial and antioxidant activities. Furthermore, the nanofiber significantly accelerated the wound healing process in a full-thickness skin injury model by enhancing wound re-epithelialization and collagen deposition density, increasing the content of macrophage antigen (CD68), platelet-endothelial cell adhesion molecule (CD31), proliferating cell nuclear antigen (PCNA) and inhibiting the expression of α-smooth muscle actin (α-SMA) at the wound site. The mechanism may be related to the inhibition of activation of phosphatidylinositol 3-kinase/serine-threonine kinase/ target of rapamycin (PI3K/AKT/mTOR) signaling pathway to enhance autophagy. Therefore, SF/PVP/PHL nanofibers can ideally meet the various requirements of the wound healing process and are promising wound dressing candidates for future clinical applications.

The Antimicrobial Effects of Bacterial Cellulose Produced by Komagataeibacter intermedius in Promoting Wound Healing in Diabetic Mice

As a conventional medical dressing, medical gauze does not adequately protect complex and hard-to-heal diabetic wounds and is likely to permit bacterial entry and infections. Therefore, it is necessary to develop novel dressings to promote wound healing in diabetic patients. Komagataeibacter intermedius was used to produce unmodified bacterial cellulose, which is rarely applied directly to diabetic wounds. The produced cellulose was evaluated for wound recovery rate, level of inflammation, epidermal histopathology, and antimicrobial activities in treated wounds. Diabetic mices' wounds treated with bacterial cellulose healed 1.63 times faster than those treated with gauze; the values for the skin indicators in bacterial cellulose treated wounds were more significant than those treated with gauze. Bacterial cellulose was more effective than gauze in promoting tissue proliferation with more complete epidermal layers and the formation of compact collagen in the histological examination. Moreover, wounds treated with bacterial cellulose alone had less water and glucose content than those treated with gauze; this led to an increase of 6.82 times in antimicrobial protection, lower levels of TNF-α and IL-6 (39.6% and 83.2%), and higher levels of IL-10 (2.07 times) than in mice wounds treated with gauze. The results show that bacterial cellulose produced using K. intermedius beneficially affects diabetic wound healing and creates a hygienic microenvironment by preventing inflammation. We suggest that bacterial cellulose can replace medical gauze as a wound dressing for diabetic patients.

Exploring the TEMPO-Oxidized Nanofibrillar Cellulose and Short Ionic-Complementary Peptide Composite Hydrogel as Biofunctional Cellular Scaffolds

Multicomponent self-assembly is an emerging approach in peptide nanotechnology to develop nanomaterials with superior physical and biological properties. Inspired by the multicomponent nature of the native extracellular matrix (ECM) and the well-established advantages of co-assembly in the field of nanotechnology, we have attempted to explore the noncovalent interactions among the sugar and peptide-based biomolecular building blocks as an approach to design and develop advanced tissue scaffolds. We utilized TEMPO-oxidized nanofibrillar cellulose (TO-NFC) and a short ionic complementary peptide, Nap-FEFK, to fabricate highly tunable supramolecular hydrogels. The differential doping of the peptide into the TO-NFC hydrogel was observed to tune the surface hydrophobicity, microporosity, and mechanical stiffness of the scaffold. Interestingly, a differential cellular response was observed toward composite scaffolds with a variable ratio of TO-NFC versus Nap-FEFK. Composite scaffolds having a 10:1 (w/w) ratio of TO-NFC and the Nap-FEFK peptide showed enhanced cellular survival and proliferation under two-dimensional cell culture conditions. More interestingly, the cellular proliferation on the 10:1 matrix was found to be similar to that of Matrigel in three-dimensional culture conditions, which clearly indicated the potential of these hydrogels in advanced tissue engineering applications. Additionally, these composite hydrogels did not elicit any significant inflammatory response in Raw cells and supported their survival and proliferation, which further emphasized their ability to form versatile scaffolds for tissue regeneration. This multicomponent assembly approach to construct biomolecular composite hydrogels to access superior physical and biological properties within the scaffold is expected to improve the scope for designing novel ECM-mimicking biomaterials for regenerative medicine.

Silk protein/polyvinylpyrrolidone nanofiber membranes loaded with puerarin accelerate wound healing in mice by reducing the inflammatory response

In modern clinical applications, wound healing remains a considerable challenge. Excessive inflammatory response is associated with delayed wound healing. In this study, we prepared composite nanofibrous membranes by mixing the Chinese herbal extract puerarin (PUE) with natural silk protein (SF) and synthetic polymer polyvinylpyrrolidone (PVP) using electrostatic spinning technique, and conducted a series of studies on the structural and biological properties of the fibrous membranes. The results showed that the loading of PUE increased the diameter, porosity and hydrophilicity of nanofibers, which were more favorable for cell adhesion and proliferation. ABTS radical scavenging assay also showed that the loading of PUE enhanced the antioxidant properties of the fibrous membranes. In addition, SF/PVP/PUE nanofibers are non-toxic and can be used as wound dressings. In vitro experiments showed that SF/PVP/PUE nanofibers could effectively alleviate lipopolysaccharide (LPS)-induced inflammation in Immortalized human keratinocytes (HaCaT) cells and down-regulate pro-inflammatory cytokine expression in cells. In vivo studies further showed that the SF/PVP/PUE nanofibers could effectively accelerate wound repair. The mechanism is that SF/PVP/PUE nanofibers can inhibit the activation and transduction of toll-like receptor 4/myeloid differentiation factor88/nuclear factor kappa B (TLR4/MyD88/NF-κB) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathways, thereby reducing the inflammatory response and achieving wound healing.

Nanocellulose, a versatile platform: From the delivery of active molecules to tissue engineering applications

Nanocellulose, a biopolymer, has received wide attention from researchers owing to its superior physicochemical properties, such as high mechanical strength, low density, biodegradability, and biocompatibility. Nanocellulose can be extracted from wide range of sources, including plants, bacteria, and algae. Depending on the extraction process and dimensions (diameter and length), they are categorized into three main types: cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC). CNCs are a highly crystalline and needle-like structure, whereas CNFs have both amorphous and crystalline regions in their network. BNC is the purest form of nanocellulose. The nanocellulose properties can be tuned by chemical functionalization, which increases its applicability in biomedical applications. This review highlights the fabrication of different surface-modified nanocellulose to deliver active molecules, such as drugs, proteins, and plasmids. Nanocellulose-mediated delivery of active molecules is profoundly affected by its topographical structure and the interaction between the loaded molecules and nanocellulose. The applications of nanocellulose and its composites in tissue engineering have been discussed. Finally, the review is concluded with further opportunities and challenges in nanocellulose-mediated delivery of active molecules.

Development of Polyvinyl Alcohol/Kaolin Sponges Stimulated by Marjoram as Hemostatic, Antibacterial, and Antioxidant Dressings for Wound Healing Promotion

The predominant impediments to cutaneous wound regeneration are hemorrhage and bacterial infections that lead to extensive inflammation with lethal impact. We thus developed a series of composite sponges based on polyvinyl alcohol (PVA) inspired by marjoram essential oil and kaolin (PVA/marjoram/kaolin), adopting a freeze-thaw method to treat irregular wounds by thwarting lethal bleeding and microbial infections. Microstructure analyses manifested three-dimensional interconnected porous structures for PVA/marjoram/kaolin. Additionally, upon increasing marjoram and kaolin concentrations, the pore diameters of the sponges significantly increased, recording a maximum of 34 ± 5.8 µm for PVA-M0.5-K0.1. Moreover, the porosity and degradation properties of PVA/marjoram/kaolin sponges were markedly enhanced compared with the PVA sponge with high swelling capacity. Furthermore, the PVA/marjoram/kaolin sponges exerted exceptional antibacterial performance against Escherichia coli and Bacillus cereus, along with remarkable antioxidant properties. Moreover, PVA/marjoram/kaolin sponges demonstrated significant thrombogenicity, developing high thrombus mass and hemocompatibility, in addition to their remarkable safety toward fibroblast cells. Notably, this is the first study to our knowledge investigating the effectiveness of marjoram in a polymeric carrier for prospective functioning as a wound dressing. Collectively, the findings suggest the prospective usage of the PVA-M0.5-K0.1 sponge in wound healing for hemorrhage and bacterial infection control.

Multi-functional nanocellulose-chitosan dressing loaded with antibacterial lawsone for rapid hemostasis and cutaneous wound healing

Cutaneous wounds accompanied by massive bleeding, bacterial infections might be lethal and cause fundamental therapeutic impediments in clinical fields. As part of the push for a solution, biomaterial having hemostatic-antibacterial features is highly desirable. Inspired by this concept, freeze dried sponges were developed followed by combining tempo-oxidized nanocellulose (TOCN), chitosan using EDC/NHS cross-linker with antibacterial lawsone loading for controlled delivery of this compound during wound healing. The pore diameter decreased upon increasing chitosan (2.5, 3.5, 4.5, 5.5% w/v) while TOCN ensured scaffold's mechanical stability. The in vitro degradation, lawsone release from fibroblast cell-compatible sponge was faster in acidic pH 5.5 than physiologic pH 7.4 indicating adaptability to physiological skin milieu of wounds. The rat tail amputation model, 14 days rat full-thickness cutaneous-wound model ensured hemostasis, dramatic wound closure after TLC4.5 (optimized scaffold) treatment suggesting its potential as functional wound healing substitute showing obvious avenue for hemostatis and skin tissue reconstruction arena.

Directional, super-hydrophobic cellulose nanofiber/polyvinyl alcohol/montmorillonite aerogels as green absorbents for oil/water separation

Nowadays, the problem of oil spill and organic solvent pollution has become more and more serious, and developing a green and efficient treatment method has become a research hotspot. Herein, the preparation of porous super‐hydrophobic aerogel by directional freezing with cellulose nanofibre (CNF) as the base material, polyvinyl alcohol (PVA) as the cross‐linking agent and montmorillonite (MMT) as the modifier and filler, followed by hydrophobic treatment with chemical vapour deposition is reported. The prepared composite aerogel presented three‐dimensional inter‐perforation network structure, low density (26.52 mg⋅cm⁻³), high porosity (96.1 %) and good hydrophobicity (water contact angle of 140°). Notably, the composite aerogel has a good adsorption effect on different oils and organic solutions, and its adsorption capacity can reach 40–68 times of its initial weight. After complete adsorption, the aerogel could be easily collected. More importantly, the composite aerogel had high strength, whose compressive stress at 70 % strain reached 0.15 MPa and could bear over 1290 times its weight without deformation after 2 weeks. A new, green, simple and efficient absorbent for the adsorption of oils and organic solvents is provided.

Recent advancements in cellulose-based biomaterials for management of infected wounds

INTRODUCTION

Chronic wounds are a substantial burden on the healthcare system. Their treatment requires advanced dressings, which can provide a moist wound environment, prevent bacterial infiltration, and act as a drug carrier. Cellulose is biocompatible, biodegradable, and can be functionalized according to specific requirements, which makes it a highly versatile biomaterial. Antimicrobial cellulose dressings are proving to be highly effective against infected wounds.

AREAS COVERED

This review briefly addresses the mechanism of wound healing and its pathophysiology. It also discusses wound infections, biofilm formation, and progressive emergence of drug-resistant bacteria in chronic wounds and the treatment strategies for such types of infected wounds. It also summarizes the general properties, method of production, and types of cellulose wound dressings. It explores recent studies and advancements regarding the use of cellulose and its derivatives in wound management.

EXPERT OPINION

Cellulose and its various functionalized derivatives represent a promising choice of wound dressing material. Cellulose-based dressings loaded with antimicrobials are very useful in controlling infection in a chronic wound. Recent studies showing its efficacy against drug-resistant bacteria make it a favorable choice for chronic wound infections. Further research and large-scale clinical trials are required for better clinical evidence of its efficiency.

A collagen-based bi-layered composite dressing for accelerated wound healing

AIM OF THE STUDY

The aim of the study was to fabricate collagen-based composite dressings, evaluate the efficiency for wound healing and reveal the mechanism of promoting wound healing.

MATERIALS AND METHODS

An innovative bi-layered composite wound dressing was developed using two marine biomacromolecules (collagen and chitosan). Full-thickness skin defect model was performed to evaluate the wound healing activity in vivo. The levels of inflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin (IL-1, IL-6, IL-8) and growth factors like transforming growth factor beta (TGF-β), vascular epidermal growth factor (VEGF) and basic fibroblast growth factor (bFGF) were quantified by ELISA assays. The total amount of collagen was quantified by hydroxyproline content. The proliferation and viability of fibroblast cells cultured on collagen sponges were determined by CCK-8 assay.

RESULTS

The results of wound closure and histopathological analysis indicated that non-crosslinked collagen-based bi-layered composite dressing stimulated wound healing, accelerated re-epithelialization and accomplished wound healing within a time span of 28 days. The results of levels of inflammatory cytokines and growth factors showed that collagen-based composite dressings could reduce the inflammatory response and upregulate growth factors levels to accelerate the wound healing. The results of hydroxyproline content and CCK-8 assay indicated that collagen-based composite dressings could also promote collagen synthesis and fibroblasts viability and proliferation.

CONCLUSION

The non-crosslinked collagen-based bi-layered composite dressing could be applied for an efficient and ideal wound dressing. Therefore, the findings provided the essential theoretical basis for the potential of collagen-based composite dressing applied in wound healing fields.

Novel chitosan-ulvan hydrogel reinforcement by cellulose nanocrystals with epidermal growth factor for enhanced wound healing: In vitro and in vivo analysis

Several dressing materials can be used efficiently in recent times, both in their natural and synthetic combinations like; microfibers, film, nanofibers, hydrogels, and various drugs. The specific characteristics, such as biocompatibility and providing a favorable environment for wound healing, make many polysaccharides pivotal as wound dressings. Keeping in view the importance of these polysaccharides, we have developed novel chitosan-ulvan hydrogel incorporated by cellulose nanocrystals (CNCs) loading epidermal growth factor (EGF) drug (CS-U-CNC-EGF) by the freeze-dried process. The morphological features of novel hydrogel were perceived by FTIR, XRD, FESEM, and DSC analysis. The incorporation of the nanocrystals content modified the porous microstructure at pore size from 237 ± 59 μm to 53 ± 16 μm, improved mechanical stress curve from 0.57 MPa to 1.2 MPa, thermal and swelling behavior. The novel nanocomposites revealed non-toxic behavior and excellent cell proliferation. Whereas hydrogel showed sustained release of the epidermal growth factor (EGF), thereby enhancing EGF delivery at the wound site for 15 days from a 100% wound contraction treated group. Moreover, the controlled release of EGF from CS-U-CNC-EGF hydrogels showed significantly faster-wound healing efficiency concerning considerably faster granulations tissue formation and collagen deposition. The study's results point to possible future applications of this composite hydrogel in wound healing as a wound dressing material.

Assessment of properties, applications and limitations of scaffolds based on cellulose and its derivatives for cartilage tissue engineering: A review

Cartilage is a connective tissue, which is made up of ~80% of water. It is alymphatic, aneural and avascular with only one type of cells present, chondrocytes. They constitute about 1-5% of the entire cartilage tissue. It has a very limited capacity for spontaneous repair. Articular cartilage defects are quite common due to trauma, injury or aging and these defects eventually lead to osteoarthritis, affecting the daily activities. Tissue engineering (TE) is a promising strategy for the regeneration of articular cartilage when compared to the existing invasive treatment strategies. Cellulose is the most abundant natural polymer and has desirable properties for the development of a scaffold, which can be used for the regeneration of cartilage. This review discusses about (i) the basic science behind cartilage TE and the study of cellulose properties that can be exploited for the construction of the engineered scaffold with desired properties for cartilage tissue regeneration, (ii) about the requirement of scaffolds properties, fabrication mechanisms and assessment of cellulose based scaffolds, (iii) details about the modification of cellulose surface by employing various chemical approaches for the production of cellulose derivatives with enhanced characteristics and (iv) limitations and future research prospects of cartilage TE.

In vitro and in vivo evaluation of a nanofiber wound dressing loaded with melatonin

Wound healing is a complicated process that takes a long time to complete. The three-layer nanofiber wound dressing containing melatonin is highly expected to show remarkable wound repair by reducing the wound healing time. In this study, chitosan (Cs)-polycaprolactone (PCL)/ polyvinylalcohol (PVA)-melatonin (MEL)/ chitosan-polycaprolactone three-layer nanofiber wound dressing was prepared by electrospinning for melatonin sustained release. The characteristics of the wound dressing were further evaluated. The wound dressing had a high water uptake after 24 h (401%), and the water contact angle results showed that it had hydrophilicity effect that supported the cell attachment. The wound healing effect of wound dressing was examined using a full-thickness excisional model of rat skin by the local administration of MEL. The gene expressions of transforming growth factor-beta (TGF-β1), alpha-smooth muscle actin (α-SMA), collagen type I (COL1A1), and collagen type III (COL3A1) were further studied. The histopathological evaluation showed the complete regeneration of the epithelial layer, remodeling of wounds, collagen synthesis, and reduction in inflammatory cells. The NF + 20% MEL significantly increased TGF-β1, COL1A1, COL3A1, and α-SMA mRNA expressions. This wound dressing may have a considerable potential as a wound dressing to accelerate the wound healing.

Biopolymeric, Nanopatterned, Fibrous Carriers for Wound Healing Applications

Background:

Any sort of wound injury leads to skin integrity and further leads to wound formation. Millions of deaths are reported every year, which contributes to an economical hamper world widely, this accounts for 10% of death rate that insight into various diseases.

Current Methodology:

Rapid wound healing plays an important role in effective health care. Wound healing is a multi-factorial physiological process, which helps in the growth of new tissue to render the body with the imperative barrier from the external environment. The complexity of this phenomenon makes it prone to several abnormalities. Wound healing, as a normal biological inherent process occurs in the body, which is reaped through four highly defined programmed phases, such as hemostasis, inflammation, proliferation, and remodeling and these phases occur in the proper progression. An overview, types, and classification of wounds along with the stages of wound healing and various factors affecting wound healing have been discussed systematically. Various biopolymers are reported for developing nanofibers and microfibers in wound healing, which can be used as a therapeutic drug delivery for wound healing applications. Biopolymers are relevant for biomedical purposes owing to biodegradability, biocompatibility, and non- toxicity. Biopolymers such as polysaccharides, proteins and various gums are used for wound healing applications. Patents and future perspectives have been given in the concluding part of the manuscript. Overall, applications of biopolymers in the development of fibers and their applications in wound healing are gaining interest in researchers to develop modified biopolymers and tunable delivery systems for effective management and care of different types of wounds.

In-situ crosslinked hydrogel based on amidated pectin/oxidized chitosan as potential wound dressing for skin repairing

Hydrogel can provide a favorable moisture environment for skin wound healing. In this study, a novel in-situ crosslinked injectable hydrogel was prepared using the water-soluble amidated pectin (AP) and oxidized chitosan (OC) through Schiff-base reaction without any chemical crosslinker. The influence of AP content on the properties of the hydrogel was systemically investigated. It showed that gelation time, pore structure, swelling capability and degradability of the hydrogel can be tuned by varying the content of amine and aldehyde groups from AP and OC. All the porous hydrogels with various AP contents (65%, 70%, and 80%) presented desirable gelation time, swelling property, high hemocompatibility and biocompatibility. Particularly, AP-OC-65 hydrogel presented superior swelling capability and better hemo- and bio-compatibility, owing to more residual amine sites in the hydrogel. Therefore, the injectable AP-OC-65 hydrogel has a greater potential for application to wound dressing or skin substitute.

Evaluation of Acetaminophen Release from Biodegradable Poly (Vinyl Alcohol) (PVA) and Nanocellulose Films Using a Multiphase Release Mechanism

Biodegradable polymers hold great therapeutic value, especially through the addition of additives for controlled drug release. Nanocellulose has shown promise in drug delivery, yet usually requires chemical crosslinking with harsh acids and solvents. Nanocellulose fibrils (NFCs) and 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)-mediated oxidized nanocellulose fibrils (TNFCs) with poly (vinyl alcohol) (PVA) could be aqueously formulated to control the release of model drug acetaminophen over 144 hours. The release was evaluated with a multiphase release mechanism to determine which mechanism(s) contribute to the overall release and to what degree. Doing so indicated that the TNFCs in PVA control the release of acetaminophen more than NFCs in PVA. Modeling showed that this release was mostly due to burst release-drug coming off the immediate surface, rather than diffusing out of the matrix.

Porous Poly(Hexamethylene Biguanide) Hydrochloride Loaded Silk Fibroin Sponges with Antibacterial Function

In order to endue silk fibroin (SF) sponges with antibacterial function, positively charged poly(hexamethylene biguanide) hydrochloride (PHMB) was incorporated in SF through electrostatic interaction and by freeze-drying technique. The influence of PHMB on the structure and antibacterial activities of SF sponges was investigated. The zeta potential of SF was increased significantly when PHMB was incorporated in SF. The pores with size from 80 to 300 µm and the microscale holes in the pore walls within PHMB-loaded SF sponges provided the channels of PHMB release. The PHMB loaded in the porous sponges showed continuous and slow release for up to 20 days. Effective growth inhibition of both Escherichia coli and Staphylococcus aureus was achieved when the mass ratio of PHMB/SF was higher than 2/100. These results suggest that the porous PHMB/SF sponges have the potential to be used as a novel wound dressing for open skin wounds.