Cationic, anionic and neutral polysaccharides for skin tissue engineering and wound healing applications

Quaternary ammonium grafted chitosan hydrogel with enhanced antibacterial performance as tannin acid and deferoxamine carrier to promote diabetic wound healing

The delay of diabetic wound healing puts a huge burden on the society. The key factors hindering wound healing include bacterial infection, unresolved inflammation and poorly generated blood vessels. In this paper, glycidyl trimethyl ammonium chloride (GTA) was grafted to chitosan (CS) to obtain quaternary ammonium grafted chitosan (QCS) with enhanced antibacterial performance, and then cross-linked by dialdehyde terminated poly(ethylene oxide) (PEO DA) to construct QCS/PEO DA hydrogel with tissue adhesion, biodegradation and self-healing properties. The QCS/PEO DA hydrogel is loaded with tannin acid (TA) and deferoxamine (DFO) to enhance antioxidant property and angiogenesis. At the same time, the TA and DFO loaded TA@DFO/hydrogel preserved the biocompatibility and biodegradability of chitosan. Moreover, the multifunctional hydrogel behaved excellent hemostatic properties in mice model and significantly promoted the healing efficacy of diabetic wounds. Overall, the TA@DFO/hydrogel is promising anti-infection dressing material for diabetic wound healing.

Recent advances in mesoporous silica nanoparticles formulations and drug delivery for wound healing

Wound healing is a natural process that can be disrupted by disease. Nanotechnology is a promising platform for the development of new therapeutic agents to accelerate acute and chronic wound healing. Drug delivery by means of nanoparticles as well as wound dressings have emerged as suitable options to improving the healing process. The characteristics of mesoporous silica nanoparticles (MSNs) make them efficient carriers of pharmaceutical agents alone or in combination with dressings. In order to maximize the effect of a drug and minimize its adverse consequences, it may be possible to include targeted and intelligent release of the drug into the design of MSNs. Its use to facilitate closure of adjacent sides of a cut as a tissue adhesive, local wound healing, controlled drug release and induction of blood coagulation are possible applications of MSNs. This review summarizes research on MSN applications for wound healing. It includes a general overview, wound healing phases, MSN formulation, therapeutic possibilities of MSNs and MSN-based drug delivery systems for wound healing.

Effects of secondary cross-linking on the physicochemical properties of sodium alginate-hydrogel and in vitro release of anthocyanins

To enhance the physicochemical properties and extend the release duration of sodium alginate (SA) hydrogels, this study explored the impact of acidifier type and the number of cross-linking on the physicochemical characteristics and in vitro anthocyanin release from SA hydrogels, utilizing calcium carbonate as the cross-linking agent. The findings revealed that the utilization of gluconolactone (GDL) as an acidifying agent in the preparation of SA hydrogels, as opposed to hydrochloric acid, resulted in a deceleration of the hydrolysis process of calcium carbonate. This deceleration led to the strengthening of hydrogen-bonding interactions and the development of a more compact network structure within the SA hydrogels. Consequently, there was a noticeable enhancement in the hardness, relaxation time, and anthocyanin encapsulation efficiency of the gels. Additionally, the release of anthocyanins in simulated intestinal fluid was delayed. Secondary cross-linking was found to facilitate ionic interactions between SA and Ca2+, further intensifying the denseness of the network structure and enhancing the physicochemical characteristics of the SA hydrogels. Overall, SA hydrogels processed with GDL as the acidifier and subjected to secondary cross-linking exhibited improved physicochemical properties, delayed release effects, and proved to be an efficient system for the delayed release of anthocyanins.

Current progress of protein-based dressing for wound healing applications - A review

Protein-based wound dressings have garnered increasing interest in recent years owing to their distinct physical, chemical, and biological characteristics. The intricate molecular composition of proteins gives rise to unique characteristics, such as exceptional biocompatibility, biodegradability, and responsiveness, which contribute to the promotion of wound healing. Wound healing is an intricate and ongoing process influenced by multiple causes, and it consists of four distinct phases. Various treatments have been developed to repair different types of skin wounds, thanks to advancements in medical technology and the recognition of the diverse nature of wounds. This review has literature reviewed within the last 3-5 years-the recent progress and development of protein in wound dressings and the fundamental properties of an ideal wound dressing. Herein, the recent strides in protein-based state-of-the-art wound dressing emphasize the significant challenges and summarize future perspectives for wound healing applications.

Genipin crosslinked quaternary ammonium chitosan hydrogels for wound dressings

Bacterial infection can lead to various complications, such as inflammations on surrounding tissues, which can prolong wound healing and thus represent a significant clinical and public healthcare problem. Herein, a report on the fabrication of a novel genipin/quaternized chitosan (CS) hydrogel for wound dressing is presented. The hydrogel was prepared by mixing quaternized CS and genipin under 35 °C bath. The hydrogels showed porous structure (250-500 μm) and mechanical properties (3000-6000 Pa). In addition, the hydrogels displayed self-healing ability and adhesion performance on different substrates. Genipin crosslinked quaternized CS hydrogels showed antibacterial activities againstE. coliandS. aureus. The CCK-8 and fluorescent images confirmed the cytocompatibility of hydrogels by seeding with NIH-3T3 cells. The present study showed that the prepared hydrogel has the potential to be used as wound dressing.

Emerging trends and challenges in polysaccharide derived materials for wound care applications: A review

Polysaccharides are favourable and promising biopolymers for wound care applications due to their abundant natural availability, low cost and excellent biocompatibility. They possess different functional groups, such as carboxylic, hydroxyl and amino, and can easily be modified to obtain the desirable properties and various forms. This review systematically analyses the recent progress in polysaccharides derived materials for wound care applications, emphasizing the most commonly used cellulose, chitosan, alginate, starch, dextran and hyaluronic acid derived materials. The distinctive attributes of each polysaccharide derived wound care material are discussed in detail, along with their different forms, i.e., films, membranes, sponges, nanoemulsions, nanofibers, scaffolds, nanocomposites and hydrogels. The processing methods to develop polysaccharides derived wound care materials are also summarized. In the end, challenges related to polysaccharides derived materials in wound care management are listed, and suggestions are given to expand their utilization in the future to compete with conventional wound healing materials.

IPN based hydrogels for in-vivo wound dressings; catalytic wound healing dynamics and isothermal adsorption models

Interpenetrating network (IPN) methacrylated chitosan or methacrylated flaxseed gum based hydrogels have been utilized to make outstanding in-vivo wound dressings. The photopolymerization process was accomplished in presence of Eosin-Y photoinitiator with average exposure time of 13-14 s for gelation. Spectroscopic structural investigations of 1H NMR. ATR-FTIR, TGA, and AFM techniques were used. In-vitro hemolysis test provided evidence of no cytotoxicity in both hydrogels observed. The in-vivo wound dressings were monitored for five mice coated with each hydrogel and another uncoated five mice for control (self-healing). All measurements were performed in quintuplicate (n = 5) and expressed as mean ± SD values. In wound healing dynamics, our data confirmed that wound healing pass through two stages; hemostasis and inflammation for stage 1, and proliferation and remodeling for stage 2. It also provided evidence of 1st order kinetics with descending rate of healing. Consequently, catalytic role of hydrogels in wound healing was checked via half-life (δ) and negative change of activation energy values (ΔEa). Various isothermal adsorption models demonstrated spontaneous and high binding affinities of hydrogels. It also confirmed the two-stage healing process in presence of hydrogels. Conclusively, the outstanding properties of the two hydrogels suggest their potential applications in treating venous ulcers and diabetic wound healing dressings.

Electrospun nanofibers synthesized from polymers incorporated with bioactive compounds for wound healing

The development of innovative wound dressing materials is crucial for effective wound care. It's an active area of research driven by a better understanding of chronic wound pathogenesis. Addressing wound care properly is a clinical challenge, but there is a growing demand for advancements in this field. The synergy of medicinal plants and nanotechnology offers a promising approach to expedite the healing process for both acute and chronic wounds by facilitating the appropriate progression through various healing phases. Metal nanoparticles play an increasingly pivotal role in promoting efficient wound healing and preventing secondary bacterial infections. Their small size and high surface area facilitate enhanced biological interaction and penetration at the wound site. Specifically designed for topical drug delivery, these nanoparticles enable the sustained release of therapeutic molecules, such as growth factors and antibiotics. This targeted approach ensures optimal cell-to-cell interactions, proliferation, and vascularization, fostering effective and controlled wound healing. Nanoscale scaffolds have significant attention due to their attractive properties, including delivery capacity, high porosity and high surface area. They mimic the Extracellular matrix (ECM) and hence biocompatible. In response to the alarming rise of antibiotic-resistant, biohybrid nanofibrous wound dressings are gradually replacing conventional antibiotic delivery systems. This emerging class of wound dressings comprises biopolymeric nanofibers with inherent antibacterial properties, nature-derived compounds, and biofunctional agents. Nanotechnology, diminutive nanomaterials, nanoscaffolds, nanofibers, and biomaterials are harnessed for targeted drug delivery aimed at wound healing. This review article discusses the effects of nanofibrous scaffolds loaded with nanoparticles on wound healing, including biological (in vivo and in vitro) and mechanical outcomes.

Umbilical cord-derived mesenchymal stem cell secretome promotes skin regeneration and rejuvenation: From mechanism to therapeutics

How to effectively repair cutaneous wounds and promote skin rejuvenation has always been a challenging issue for clinical medicine and medical aesthetics. Current conventional medicines exhibit several drawbacks, including limited therapeutic effects, prolonged treatment periods, and high costs. As a novel cell-free therapy, the umbilical cord-derived mesenchymal stem cell (UCMSC) secretome may offer a promising approach for skin regeneration and rejuvenation. The UCMSC secretome is a collection of all proteins secreted by mesenchymal stem cells, including conditioned media, exosomes, and other substances. The UCMSC secretome has numerous abilities to accelerate acute wound healing, including high fibroblast and keratinocyte proliferative activity, pro-angiogenesis, anti-inflammation, anti-fibrosis, and anti-oxidative stress. Its impact on the four stages of wound healing is manifested by inducing the haemostasis phase, inhibiting the inflammation phase, promoting the proliferation phase, and regulating the remodelling phase. Furthermore, it is highly effective in the treatment of chronic wounds, alopecia, aging, and skin homeostasis disturbance. This review focuses on the clinical therapies and application prospects of the UCMSC secretome, encompassing its source, culture, separation, identification, storage, and pretreatment. Additionally, a discussion on the dosage, administration route, efficacy, and biosafety in the clinical situation is presented. This review aims to provide scientific support for the mechanistic investigation and clinical utilisation of the UCMSC secretome in wound healing and skin rejuvenation.

Identification of Gluconacetobacter xylinus LYP25 and application to bacterial cellulose production in biomass hydrolysate with acetic acid

Bacterial cellulose (BC) is a remarkable biomacromolecule with potential applications in food, biomedical, and other industries. However, the low economic feasibility of BC production processes hinders its industrialization. In our previous work, we obtained candidate strains with improved BC production through random mutations in Gluconacetobacter. In this study, the molecular identification of LYP25 strain with significantly improved productivity, the development of chestnut pericarp (CP) hydrolysate medium, and its application in BC fermentation were performed for cost-effective BC production process. As a result, the mutant strain was identified as Gluconacetobacter xylinus. The CP hydrolysate (CPH) medium contained 30 g/L glucose with 0.4 g/L acetic acid, whereas other candidates known to inhibit fermentation were not detected. Although acetic acid is generally known as a fermentation inhibitor, it improves the BC production by G. xylinus when present within about 5 g/L in the medium. Fermentation of G. xylinus LYP25 in CPH medium resulted in 17.3 g/L BC, a 33 % improvement in production compared to the control medium, and BC from the experimental and control groups had similar physicochemical properties. Finally, the overall process of BC production from biomass was evaluated and our proposed platform showed the highest yield (17.9 g BC/100 g biomass).

Recent Advances of Chitosan-Based Hydrogels for Skin-Wound Dressings

The management of wound healing represents a significant clinical challenge due to the complicated processes involved. Chitosan has remarkable properties that effectively prevent certain microorganisms from entering the body and positively influence both red blood cell aggregation and platelet adhesion and aggregation in the bloodstream, resulting in a favorable hemostatic outcome. In recent years, chitosan-based hydrogels have been widely used as wound dressings due to their biodegradability, biocompatibility, safety, non-toxicity, bioadhesiveness, and soft texture resembling the extracellular matrix. This article first summarizes an overview of the main chemical modifications of chitosan for wound dressings and then reviews the desired properties of chitosan-based hydrogel dressings. The applications of chitosan-based hydrogels in wound healing, including burn wounds, surgical wounds, infected wounds, and diabetic wounds are then discussed. Finally, future prospects for chitosan-based hydrogels as wound dressings are discussed. It is anticipated that this review will form a basis for the development of a range of chitosan-based hydrogel dressings for clinical treatment.

Development of Antioxidant and Antimicrobial Membranes Based on Functionalized and Crosslinked Chitosan for Tissue Regeneration

Tissue engineering is an interdisciplinary field that develops new methods to enhance the regeneration of damaged tissues, including those of wounds. Polymer systems containing bioactive molecules can play an important role in accelerating tissue regeneration, mitigating inflammation process, and fighting bacterial infection. Chitosan (CS) has attracted much attention regarding its use in wound healing system fabrication thanks to its biocompatibility, biodegradability, and the presence of functional groups in its structure. In this work, bioactive chitosan-based membranes were obtained by both chemical and physical modifications of the polymer with glycidyl methacrylate and glycerol (GLY), respectively. The most suitable GLY concentration to obtain wound healing systems with good elongation at break, a good water vapor transmission rate (WVTR), and good wettability values was 20% (w/w). Afterwards, the membranes were crosslinked with different concentrations of ethylene glycol dimethacrylate (EGDMA). By using a concentration of 0.05 mM EGDMA, membranes with a contact angle and WVTR values suitable for the application were obtained. To make the system bioactive, 3,4-dihydrocinnamic acid (HCAF) was introduced into the membranes, either by imbibition or chemical reaction, using laccase as a catalyst. Thermal and mechanical analyses confirmed the formation of a cohesive network, which limited the plasticizing effect of GLY, particularly when HCAF was chemically bound. The HCAF-imbibed membrane showed a good antioxidant and antimicrobial activity, highlighting the potential of this system for the treatment of wound healing.

Preparation and characterization of a jelly fig (Ficus awkeotsang Makino) polysaccharide-based bioactive 3D scaffold for improved vascularization and skin tissue engineering applications

Jelly fig polysaccharides (JFP) were extracted from Ficus awkeotsang Makino achenes. The yield of JFP was approximately 10-15 %. FT-IR spectrum of the extracted JFP confirmed that it was made of low methoxyl pectin (LMP). 3D scaffolds of JFP (JFP scaffold) were fabricated using ionic crosslinking of 2 % (w/v) JFP solution with Ca2+ ions and freeze-drying. The JFP scaffold showed 73.46 ± 1.97 % porosity and a 12-fold swelling capacity. The porous morphology was also observed in SEM micrographs. JFP scaffolds were completely degraded in 14 days when incubated in 1 mg/mL lysozyme solution, compared to the 50 % degradation observed in PBS alone. The antioxidant activity of the JFP and JFP scaffold was approximately 40 %. The hemolytic assay of the JFP scaffold showed <5 % (3.0 ± 0.4) RBC lysis. The cytocompatibility of the JFP scaffold was evaluated using L929 mouse fibroblasts and human dermal fibroblasts (HDF). The in vitro studies using L929 cells showed that the JFP scaffold is cytocompatible. HDF cells cultured in the presence of JFP scaffolds show a higher fold cell viability, proliferation, and migration. Collagen expression and deposition were also studied, and no significant changes occurred with JFP scaffold treatment. In vivo CAM assay showed an increase in the number and thickness of blood vessels by 1.185-fold and 1.19-fold, respectively. These results confirm the angiogenic property of the JFP scaffold. These biocompatible and bioactive properties of the JFP scaffold could be beneficial for tissue engineering and regenerative medicine applications.

Metal Nanoparticles: Advanced and Promising Technology in Diabetic Wound Therapy

Diabetic wounds pose a significant challenge to public health, primarily due to insufficient blood vessel supply, bacterial infection, excessive oxidative stress, and impaired antioxidant defenses. The aforementioned condition not only places a significant physical burden on patients' prognosis, but also amplifies the economic strain on the medical system in treating diabetic wounds. Currently, the effectiveness of available treatments for diabetic wounds is limited. However, there is hope in the potential of metal nanoparticles (MNPs) to address these issues. MNPs exhibit excellent anti-inflammatory, antioxidant, antibacterial and pro-angiogenic properties, making them a promising solution for diabetic wounds. In addition, MNPs stimulate the expression of proteins that promote wound healing and serve as drug delivery systems for small-molecule drugs. By combining MNPs with other biomaterials such as hydrogels and chitosan, novel dressings can be developed and revolutionize the treatment of diabetic wounds. The present article provides a comprehensive overview of the research progress on the utilization of MNPs for treating diabetic wounds. Building upon this foundation, we summarize the underlying mechanisms involved in diabetic wound healing and discuss the potential application of MNPs as biomaterials for drug delivery. Furthermore, we provide an extensive analysis and discussion on the clinical implementation of dressings, while also highlighting future prospects for utilizing MNPs in diabetic wound management. In conclusion, MNPs represent a promising strategy for the treatment of diabetic wound healing. Future directions include combining other biological nanomaterials to synthesize new biological dressings or utilizing the other physicochemical properties of MNPs to promote wound healing. Synthetic biomaterials that contain MNPs not only play a role in all stages of diabetic wound healing, but also provide a stable physiological environment for the wound-healing process.

Facile preparation of self-healing hydrogels based on chitosan and PVA with the incorporation of curcumin-loaded micelles for wound dressings

The increased demand for improved strategies for wound healing has, in recent years, motivated the development of multifunctional hydrogels with favorable bio-compatibility and antibacterial properties. To this regard, the current study presented the design of a novel self-healing composite hydrogel that could perform as wound dressing for the promotion of wound healing. The composite hydrogels were composed of polyvinyl alcohol (PVA), borax and chitosan functionalized with sialic acid (SA-CS) and curcumin loaded pluronic F127 micelles. The hydrogels were formed through the boronic ester bond formation between PVA, SA-CS and borax under physiological conditions and demonstrated adjustable mechanical properties, gelation kinetics and antibacterial properties. When incubating with NIH3T3 cells, the hydrogels also demonstrated good biocompatibility. These aspects offer a promising foundation for their prospective applications in developing clinical materials for wound healing.

Dendrobium officinale Kimura & Migo polysaccharide and its multilayer emulsion protect skin photoaging

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium officinale Kimura & Migo is traditionally used to treat skin diseases, gastrointestinal diseases, and other diseases. Dendrobium officinale polysaccharides (DOP) are the main component of Dendrobium officinale that accounts for its bioactivity, which shows a variety of effects such as moisturizing, antioxidant and anti-fatigue. However, there is no comprehensive study on the effect of DOP on skin photoaging combined with in vitro and in vivo models, and its specific mechanism is still unclear.

AIM OF THE STUDY

Our study aimed to explore the effect and underlying mechanism of DOP on skin photoaging, as well as to improve the stability and transdermal absorption of DOP.

MATERIALS AND METHODS

DOP was extracted, purified and structurally characterized. In vitro HaCaT cell photoaging model was used to examine the photoprotection effect of DOP. Cell viability was detected by CCK-8; Intracellular reactive oxygen species were determined by DCFH-DA; DNA damage, cell apoptosis and cell cycle arrest were examined by flow cytocytometry. For autophagy flux detection, the adenovirus loaded with mRFP-GFP-LC3 was introduced into cells. Further, to enhance the stability and absorption of DOP, we designed and prepared the W/O/W type DOP multilayer emulsions (ME) by a two-step emulsification method. The emulsion stability, drug loading and encapsulation rate, DOP stability and DOP transdermal rate were detected. In vivo photoaging animal model was applied to compare the difference of photoaging protection effect between DOP solution and DOP ME. Specifically, skin appearance, histological change, antioxidant system, proinflammatory indicators, matrix metalloproteinases and autophagy level of skin tissues were examined and compared.

RESULTS

The results showed that DOP achieve photoaging protection by inhibiting oxidative stress, alleviating cell cycle arrest and apoptosis, and enhancing autophagy flux in photoaged HaCaT cells. The W/O/W type DOP multilayer emulsion (ME) with high encapsulation rate and strong stability was found to significantly improve the stability and transdermal absorption of DOP. In addition, our results showed that DOP (ME) remarkably improved skin condition of photoaged mice. Specifically, DOP (ME) enhanced the expression of antioxidant enzymes and autophagy and decreased the levels of pro-inflammatory factors and matrix metalloproteinases in the skin of photoaged mice as compared with DOP solution.

CONCLUSIONS

In conclusion, DOP was effective in improving skin photoaging, and the DOP multilayer emulsion we designed enhanced the stability and skin absorption of DOP, boosting DOP's protective effect against photoaging.

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

Essential Oils of Some Potential Medicinal Plants and their Wound Healing Activities

The wound has been recognised as a deep cut or tearing of the epidermis, which is also referred to as trauma and harm to the body tissues. Healing of wounds requires a coordinated series of cellular processes, including cell attraction, proliferation, differentiation, and angiogenesis. These processes involve interactions between various cells, such as macrophages, endothelial cells, keratinocytes, fibroblasts, growth hormones, and proteases. The outcome of wounds can be fatal if not treated properly, resulting in chronic wounds, chronic pain, and even death. Wound healing is replacing missing tissue with tissue repairs and regeneration. Some local variables are the presence of tissue maceration, foreign objects, biofilm, hypoxia, ischemia, and wound infection. Sustained growth factor delivery, siRNA delivery, micro-RNA targeting, and stem cell therapy are all emerging possible therapeutic approaches for wound healing. Traditional approaches, such as Ayurveda, Siddha, and Unani medicines, are also being used for treatment. The therapeutic application of nanoformulations in wound infections has shown various beneficial effects. Several herbal medicines, especially essential oils have shown potential wound healing activities, such as lavender, tea tree, sesame, olive, etc. Various nanoparticles and their nanoformulations have been explored in wound healing therapy. The present review article highlights several aspects of essential oils for wound healing activity through a novel drug delivery system. Further, some patents on wound healing through herbal medicine have been listed.

Advances in Chronic Wound Management: From Conventional Treatment to Novel Therapies and Biological Dressings

Chronic wounds can be classified as diabetic foot ulcers, pressure ulcers, or venous leg ulcers. Chronic wound management has become a threat to clinicians and constitutes a major healthcare burden. The healing process of chronic wounds requires many factors to work in concert to achieve optimal healing. Various treatment options, ranging from hypoxia to infection, have evolved considerably to address the challenges associated with chronic wound healing. The conventional and accelerating treatments for chronic wounds still represent an unmet medical need due to the complex pathophysiology of the chronic wound microenvironment. In clinical settings, traditional chronic wound care practices rely on nonspecific topical treatment, which can reduce pain and alleviate disease progression with varying levels of success but fail to completely cure the wounds. Conventional wound dressings, such as hydrocolloids, gauze, foams, and films, have also shown limited success for the treatment of chronic wounds and only act as a physical barrier and absorb wound exudates. Emerging advances in treatment approaches, including novel therapies (stem cells, microRNAs, and nanocarrier-based delivery systems) and multifunctional biological dressings, have been reported for chronic wound repair. This review summarizes the challenges offered by chronic wounds and discusses recent advancements in chronic wound treatment.

Multiple Natural Polymers in Drug and Gene Delivery Systems

Natural polymers are organic compounds produced by living organisms. In nature, they exist in three main forms, including proteins, polysaccharides, and nucleic acids. In recent years, with the continuous research on drug and gene delivery systems, scholars have found that natural polymers have promising applications in drug and gene delivery systems due to their excellent properties such as biocompatibility, biodegradability, low immunogenicity, and easy modification. However, since the structure, physicochemical properties, pharmacological properties and biological characteristics of biopolymer molecules have not yet been entirely understood, further studies are required before large-scale clinical application. This review focuses on recent advances in the representative natural polymers such as proteins (albumin, collagen, elastin), polysaccharides (chitosan, alginate, cellulose) and nucleic acids. We introduce the characteristics of various types of natural polymers, and further outline the characterization methods and delivery forms of these natural polymers. Finally, we discuss possible challenges for natural polymers in subsequent experimental studies and clinical applications. It provides an important strategy for the clinical application of natural polymers in drug and gene delivery systems.

Protein/polysaccharide-based hydrogels loaded probiotic-mediated therapeutic systems: A review

The natural characteristics of protein/polysaccharide-based hydrogels, as a potential drug delivery platform, have attracted extensive attention. Probiotics have attracted renewed interest in drug research because of their beneficial effects on host health. The idea of using probiotics loaded on protein/polysaccharide-based hydrogels as potential drugs to treat different diseases has been put forward and shows great prospects. Based on this, in this review, we highlight the design strategy of hydrogels loaded probiotic-mediated therapy systems and review the potential diseases that have been proved to be treatable in the laboratory, including promoting wound healing and improving intestinal health and vaginal health, and discuss the challenges existing in the current design.

Cerium oxide nanoparticles: Synthesis methods and applications in wound healing

Wound care and treatment can be critical from a clinical standpoint. While different strategies for the management and treatment of skin wounds have been developed, the limitations inherent in the current approaches necessitate the development of more effective alternative strategies. Advances in tissue engineering have resulted in the development of novel promising approaches for accelerating wound healing. The use of various biomaterials capable of accelerating the regeneration of damaged tissue is critical in tissue engineering. In this regard, cerium oxide nanoparticles (CeO2 NPs) have recently received much attention because of their excellent biological properties, such as antibacterial, anti-inflammatory, antioxidant, and angiogenic features. The incorporation of CeO2 NPs into various polymer-based scaffolds developed for wound healing applications has led to accelerated wound healing due to the presence of CeO2 NPs. This paper discusses the structure and functions of the skin, the wound healing process, different methods for the synthesis of CeO2 NPs, the biological properties of CeO2 NPs, the role of CeO2 NPs in wound healing, the use of scaffolds containing CeO2 NPs for wound healing applications, and the potential toxicity of CeO2 NPs.

Polysaccharide-bioceramic composites for bone tissue engineering: A review

Limitations associated with conventional bone substitutes such as autografts, increasing demand for bone grafts, and growing elderly population worldwide necessitate development of unique materials as bone graft substitutes. Bone tissue engineering (BTE) would ensure therapy advancement, efficiency, and cost-effective treatment modalities of bone defects. One way of engineering bone tissue scaffolds by mimicking natural bone tissue composed of organic and inorganic phases is to utilize polysaccharide-bioceramic hybrid composites. Polysaccharides are abundant in nature, and present in human body. Biominerals, like hydroxyapatite are present in natural bone and some of them possess osteoconductive and osteoinductive properties. Ion doped bioceramics could substitute protein-based biosignal molecules to achieve osteogenesis, vasculogenesis, angiogenesis, and stress shielding. This review is a systemic summary on properties, advantages, and limitations of polysaccharide-bioceramic/ion doped bioceramic composites along with their recent advancements in BTE.

Protein-polysaccharide-based delivery systems for enhancing the bioavailability of curcumin: A review

In recent years, a wide attention has been paid to curcumin in medicine due to its excellent physiological activities, including anti-inflammatory, antioxidant, antibacterial, and nerve damage repair. However, the low solubility, poor stability, and rapid metabolism of curcumin make its bioavailability low, which affects its development and application. As a unique biopolymer structure, protein-polysaccharide (PRO-POL)-based delivery system has the advantages of low toxicity, biocompatibility, biodegradability, and delayed release. Many scholars have investigated PRO-POL -based delivery systems to improve the bioavailability of curcumin. In this paper, we focus on the interactions between different proteins (e.g. casein, whey protein, soybean protein isolate, pea protein, zein, etc.) and polysaccharides (chitosan, sodium alginate, hyaluronic acid, pectin, etc.) and their effects on complexes diameter, surface charge, encapsulation drive, and release characteristics. The mechanism of the PRO-POL-based delivery system to enhance the bioavailability of curcumin is highlighted. In addition, the application of PRO-POL complexes loaded with curcumin is summarized, aiming to provide a reference for the construction and application of PRO-POL delivery systems.

Polysaccharide‑platinum complexes for cancer theranostics

Platinum anticancer drugs have been explored and developed in recent years to reduce systematic toxicities and resist drug resistance. Polysaccharides derived from nature have abundant structures as well as pharmacological activities. The review provides insights on the design, synthesis, characterization and associating therapeutic application of platinum complexes with polysaccharides that are classified by electronic charge. The complexes give birth to multifunctional properties with enhanced drug accumulation, improved tumor selectivity and achieved synergistic antitumor effect in cancer therapy. Several techniques developing polysaccharides-based carriers newly are also discussed. Moreover, the lasted immunoregulatory activities of innate immune reactions triggered by polysaccharides are summarized. Finally, we discuss the current shortcomings and outline potential strategies for improving platinum-based personalized cancer treatment. Using platinum-polysaccharides complexes for improving the immunotherapy efficiency represents a promising framework in future.

Preparation of Ultra-Small Copper Nanoparticles-Loaded Self-Healing Hydrogels with Antibacterial, Inflammation-Suppressing and Angiogenesis-Enhancing Properties for Promoting Diabetic Wound Healing

Background

Bacterial invasion, protracted inflammation, and angiogenesis inhibition are hallmarks of chronic diabetic wounds, bringing about patient morbidity and rising healthcare costs. For such wounds, there are currently few efficient therapies available.

Methods

We reported the development of carboxymethyl chitosan (CMCS)-based self-healing hydrogel loaded with ultra-small copper nanoparticles (Cunps) for local treatment of diabetic wound healing. The structure of Cunps was identified by XRD, TEM, XPS and other methods, and the characterization of the synthesized Cunps-loaded self-healing carboxymethyl chitosan (CMCS)-protocatechualdehyde (PCA) hydrogel (Cunps@CMCS-PCA hydrogel) was further investigated. The therapeutic effect of Cunps@CMCS-PCA hydrogel in diabetic wound healing was explored in vitro and in vivo.

Results

The findings showed that a kind of ultra-small size copper nanoparticles with excellent biocompatibility was prepared. CMCS was chemically conjugated to PCA to form self-healing hydrogels via the formation of an amide bond followed by the loading of ultra-small copper nanoparticles. The obtained Cunps@CMCS-PCA hydrogel showed a typical three-dimensional interlinked network structure with self-healing ability and porosity. It exhibited good biocompatibility in diabetic wounds. Furthermore, Cunps@CMCS-PCA hydrogel group significantly prevented bacterial growth in the skin wound of diabetic rats as compared to model group and CMCS-PCA hydrogel-treated group. After 3 days, no visible bacterial proliferation was observed. It also increased angiogenesis through Cunps mediated activation of ATP7A to prevent induction of autophagy. Furthermore, Cunps@CMCS-PCA hydrogel mainly depended on PCA-induced inhibition on inflammation of macrophage via JAK2/STAT3 signaling pathway. As a result, compared with delayed wound healing process with lower wound healing rate valued at 68.6% within 7 days in the model group, Cunps@CMCS-PCA significantly accelerated wound healing recovery and increased wound healing rate to 86.5%, suggesting that Cunps@CMCS-PCA hydrogel effectively accelerated wound healing.

Conclusion

Cunps@CMCS-PCA hydrogel offered a new therapeutic approach for quickening diabetic wound healing.

Agaricus blazei Murill polysaccharides/alginate/poly(vinyl alcohol) blend as dressings for wound healing

Macromolecules with antioxidant properties such as polysaccharides from Agaricus blazei Murill mushroom (PAbs) are an excellent option for manufacturing wound dressings. Based on this, this study aimed to analyze preparation, physicochemical characterization, and assessment of the potential wound-healing activity of films based on sodium alginate and polyvinyl alcohol loaded with PAbs. PAbs did not significantly alter the cell viability of human neutrophils in a concentration range of 1-100 μg mL^-1. The Infrared Spectroscopy (FTIR) indicates that the components present in the films (PAbs/Sodium Alginate (SA)/Polyvinyl Alcohol (PVA)) present an increase in hydrogen bonds due to the increase of hydroxyls present in the components. Thermogravimetry (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD) characterizations indicate a good miscibility between the components where PAbs increasing the amorphous characteristics of the films and that the addition of SA increased the mobility of the chains PVA polymers. The addition of PAbs to films significantly improves properties such as mechanical, thickness, and water vapor permeation. The morphological study evidenced good miscibility between the polymers. The wound healing evaluation indicated that F100 film presented better results from the fourth day onward compared to the other groups. It favored the formation of a thicker dermis (476.8 ± 18.99 μm), with greater collagen deposition and a significant reduction in malondialdehyde and nitrite/nitrate, markers of oxidative stress. These results indicate that PAbs is a candidate for wound dressing.

Preparation of Apoptotic Extracellular Vesicles from Adipose Tissue and Their Efficacy in Promoting High-Quality Skin Wound Healing

Purpose

A lot of strategies have been attempted to achieve high-quality skin wound healing, among them, fat transplantation has been used for skin wound repair and scar management and has shown beneficial effects. However, the underlying mechanism is still unclear. Recently, studies found that transplanted cells underwent apoptosis within a short period and apoptotic extracellular vesicles (ApoEVs) might play the therapeutic role.

Methods

In this study, we directly isolated apoptotic extracellular vesicles from adipose tissue (ApoEVs-AT) and evaluated their characteristics. In vivo, we investigated the therapeutic role of ApoEVs-AT in full-thickness skin wounds. The rate of wound healing, the quality of granulation tissue, and the area of scars were evaluated here. In vitro, we investigated the cellular behaviors of fibroblasts and endothelial cells induced by ApoEVs-AT, including cellular uptake, proliferation, migration, and differentiation.

Results

ApoEVs-AT could be successfully isolated from adipose tissue and possessed the basic characteristics of ApoEVs. In vivo, ApoEVs-AT could accelerate skin wound healing, improve the quality of granulation tissue, and reduce the area of scars. In vitro, ApoEVs-AT could be engulfed by fibroblasts and endothelial cells, significantly enhancing their proliferation and migration. Moreover, ApoEVs-AT could promote adipogenic differentiation and inhibit the fibrogenic differentiation of fibroblasts.

Conclusion

These findings indicated that ApoEVs could be successfully prepared from adipose tissue and showed the ability to promote high-quality skin wound healing by modulating fibroblasts and endothelial cells.

Antibacterial and hemostatic polyvinyl alcohol/microcrystalline cellulose reinforced sodium alginate breathable dressing containing Euphorbia humifusa extract based on microfluidic spinning technology

Antibacterial hemostatic medical dressings have become feasible solutions in response to the challenging wound-healing process. In this study, a novel fiber-type medical dressing with excellent breathable, antibacterial, and hemostatic qualities was created using sodium alginate (SA), microcrystalline cellulose (MCC), polyvinyl alcohol (PVA), and Euphorbia humifusa Willd (EHW) based on microfluidic spinning technology, and the properties of the dressing were characterized. The orthogonal test demonstrates that PVA and MCC can enhance the mechanical properties of the fiber, which is a crucial requirement for fiber assembly to form the dressing. Moreover, the presence of EHW enhances the dressing's antibacterial and hemostatic qualities. The dressings have been proven to have potent antibacterial and hemostatic properties as well as the ability to considerably speed up wound healing and skin tissue regeneration in the in-vitro and in-vivo tests. In conclusion, this innovative fiber-type medical dressing containing SA, MCC, PVA, and EHW has enormous potential for managing wounds caused by bacteria.

The impact of Allgower-Donati suture pattern and postoperative sweet foods on wound suture breakage in experimental rats

Background

Wound gnawing and/or scratching in rats often occurs in experimental models, causing suture breakage and wound dehiscence, and consequently affecting experimental results and wasting resources. This study aimed to investigate the impact of the combined postoperative use of the Allgower-Donati (A-D) suture pattern and sweet foods on suture breakage, inflammation, and healing in wounds.

Materials and methods

Sprague Dawley (SD) rats (n = 48) were treated for linear wounds on the back by four procedures: simple suture, simple suture with postoperative sweet foods, A-D suture, and A-D suture with postoperative sweet foods. Additionally, CD68 immunofluorescence and CD31 immunohistochemistry were used to analyze wound inflammation and vascularization, respectively, on postoperative day 7. Sirius red staining was used to assess collagen deposition on postoperative day 14.

Results

Gnawing and scratching of wound sutures were significantly reduced in treated rats (P < 0.01). Neovascularization and collagen deposition were significantly increased (P < 0.001), and inflammatory responses were significantly reduced (P < 0.001) in animals receiving AD sutures and postoperative sweet foods. CD31/CD68 analyses showed that A-D suture and postoperative sweet foods regulated wound angiogenesis and attenuated wound inflammation.

Conclusions

Sweet food provision after A-D suture union surgery could reduce wound gnawing and/or scratching, suture breakage, incisional dehiscence, wound inflammation, and promote wound healing in rats.

Heparin-based sericin hydrogel-encapsulated basic fibroblast growth factor for in vitro and in vivo skin repair

The treatment of full-thickness cutaneous wounds remains a significant challenge in clinical therapeutics. Exogenous growth factor (GF) has been applied in clinics to promote wound healing. However, the retention of GF on the wound bed after its direct application to the wound surface is difficult. Moreover, growth factors (GFs) are always inactivated in the complex wound healing microenvironment due to various factors, which significantly decrease the therapeutic effect. Sericin hydrogel (S) can be used as an effective carrier for GFs owing to its low immunogenicity, good biocompatibility, and good healing-promoting ability. Here, we designed a heparin-based sericin hydrogel (HS) -encapsulated basic fibroblast growth factor (bFGF-HS) to facilitate wound healing and skin regeneration. The hydrogel exhibited a three-dimensional (3D) microporous structure, excellent biodegradability, good adhesiveness, and low cytotoxicity. In vitro release of bFGF from bFGF-HS coacervates revealed that bFGF-HS might control the release of bFGF within 25 days through heparin regulation. bFGF-HS significantly promoted vascularization and re-epithelialization and improved collagen deposition, ultimately accelerating wound healing in vivo in mice. bFGF-HS treated wounds were also found to have more hair follicles and milder inflammatory reactions. Overall, this study provides a new therapeutic approach for full-thickness skin defect wounds using bFGF-HS.

Past, present and future of biomedical applications of dextran-based hydrogels: A review

This review extensively surveys the biomedical applications of hydrogels containing dextran. Dextran has gained much attention as a biomaterial due to its distinctive properties such as biocompatibility, non-toxicity, water solubility and biodegradability. It has emerged as a critical constituent of hydrogels for biomedical applications including drug delivery devices, tissue engineering scaffolds and biosensor materials. The benefits, challenges and potential prospects of dextran-based hydrogels as biomaterials are highlighted in this review.

A Novel Dressing Composed of Adipose Stem Cells and Decellularized Wharton's Jelly Facilitated Wound Healing and Relieved Lymphedema by Enhancing Angiogenesis and Lymphangiogenesis in a Rat Model

Lymphedema causes tissue swelling due to the accumulation of lymphatic fluid in the tissue, which delays the process of wound-healing. Developing effective treatment options of lymphedema is still an urgent issue. In this study, we aim to fabricate tissue-engineered moist wound dressings with adipose stem cells (ASCs) and decellularized Wharton's jelly (dWJ) from the human umbilical cord in order to ameliorate lymphedema. Rat ASCs were proliferated and an apparent layer was observed on dWJ at day 7 and 14. A rat tail lymphedema model was developed to evaluate the efficacy of the treatment. Approximately 1 cm of skin near the base of the rat tail was circularly excised. The wounds were treated by secondary healing (control) (n = 5), decellularized Wharton's jelly (n = 5) and ASC-seeded dWJ (n = 5). The wound-healing rate and the tail volume were recorded once a week from week one to week five. Angiogenesis and lymphangiogenesis were assessed by immunochemistry staining with anti-CD31 and anti-LYVE1. The results showed that the wound-healing rate was faster and the tail volume was lesser in the ASC-seeded dWJ group than in the control group. More CD31+ and LYVE-1+ cells were observed at the wound-healing area in the ASC-seeded dWJ group than in the control group. This proves that tissue-engineered moist wound dressings can accelerate wound-healing and reduce lymphedema by promoting angiogenesis and lymphangiogenesis.

Effects of sericin and egg white on the inflammation of damaged skin in mice

Sericin and egg white (EW) have shown the ability to promote wound healing. However, there have been insufficient studies regarding the effects of sericin and EW mixtures on wound healing. This study aimed to investigate the effects of a hybrid sericin and EW solution on wound repair and inflammation-related indicators in mouse skin. In this work, sericin with a low molecular weight was first mixed with homogeneous EW to prepare a hybrid wound dressing. Histology evaluation, the expression of C-reactive protein (CRP) and inflammatory cytokines in mice were tested to determine the effects of this dressing on skin injuries in mice. The results showed that sericin and the hybrid solution of sericin and EW effectively promoted wound healing in mouse skin. The wound recovery rates of mice 12 days after treatment with a medium dose of sericin (0.2 g ml^-1) and the same dosage of sericin with added EW were 1.32 and 1.65 times that of mice treated with phosphate buffer saline as a control, respectively. In addition, the mixture solution was more effective in wound healing than sericin alone. Sericin with EW significantly reduced the expression of CRP and inflammatory cytokines in mice during wound healing. A sericin and EW hybrid solution can effectively shorten the time needed for wound healing and reduce inflammation-related indicators in mice, making it a promising candidate for wound dressing.

Novel Scaffold Based on Chitosan Hydrogels/Phthalated Cashew Gum for Supporting Human Dental Pulp Stem Cells

Hydrogels are structures that have value for application in the area of tissue engineering because they mimic the extracellular matrix. Naturally obtained polysaccharides, such as chitosan (CH) and cashew gum, are materials with the ability to form polymeric networks due to their physicochemical properties. This research aimed to develop a scaffold based on chitosan and phthalated cashew tree gum and test it as a support for the growth of human mesenchymal stem cells. In this study, phthalation in cashew gum (PCG) was performed by using a solvent-free route. PCG-CH scaffold was developed by polyelectrolyte complexation, and its ability to support adherent stem cell growth was evaluated. The scaffold showed a high swelling rate. The pore sizes of the scaffold were analyzed by scanning electron microscopy. Human dental pulp stem cells (hDPSCs) were isolated, expanded, and characterized for their potential to differentiate into mesenchymal lineages and for their immunophenotypic profile. Isolated mesenchymal stem cells presented fibroblastoid morphology, plastic adhesion capacity, and differentiation in osteogenic, adipogenic, and chondrogenic lineages. Mesenchymal stem cells were cultured in scaffolds to assess cell adhesion and growth. The cells seeded on the scaffold showed typical morphology, attachment, and adequate distribution inside the matrix pores. Thus, cells seeded in the scaffold may improve the osteoinductive and osteoconductive properties of these biomaterials.

Nanomaterials-Based Wound Dressing for Advanced Management of Infected Wound

The effective prevention and treatment of bacterial infections is imperative to wound repair and the improvement of patient outcomes. In recent years, nanomaterials have been extensively applied in infection control and wound healing due to their special physiochemical and biological properties. Incorporating antibacterial nanomaterials into wound dressing has been associated with improved biosafety and enhanced treatment outcomes compared to naked nanomaterials. In this review, we discuss progress in the application of nanomaterial-based wound dressings for advanced management of infected wounds. Focus is given to antibacterial therapy as well as the all-in-one detection and treatment of bacterial infections. Notably, we highlight progress in the use of nanoparticles with intrinsic antibacterial performances, such as metals and metal oxide nanoparticles that are capable of killing bacteria and reducing the drug-resistance of bacteria through multiple antimicrobial mechanisms. In addition, we discuss nanomaterials that have been proven to be ideal drug carriers for the delivery and release of antimicrobials either in passive or in stimuli-responsive manners. Focus is given to nanomaterials with the ability to kill bacteria based on the photo-triggered heat (photothermal therapy) or ROS (photodynamic therapy), due to their unparalleled advantages in infection control. Moreover, we highlight examples of intelligent nanomaterial-based wound dressings that can detect bacterial infections in-situ while providing timely antibacterial therapy for enhanced management of infected wounds. Finally, we highlight challenges associated with the current nanomaterial-based wound dressings and provide further perspectives for future improvement of wound healing.

Enzymatic one-pot preparation of carboxylmethyl chitosan-based hydrogel with inherent antioxidant and antibacterial properties for accelerating wound healing

Facile preparation of multifunctional hydrogel wound dressings with inherent versatile properties is highly desirable in practical healthcare. Here, a biocompatible hydrogel was designed and fabricated via mild enzymatic crosslinking and polymerization. We first designed an enzymatic system containing horseradish peroxidase (HRP), H₂O₂, and the macromolecular initiator-acetoacetyl polyvinyl alcohol (PVA-ACAC), which can generate active PVA-ACAC carbon radicals via HRP-mediated oxidation by H₂O₂. Trimethylammonium chloride (Q), methacryloyl (MA) and phenol (Ph)-grafted carboxymethyl chitosan (Ph-QCMCS-MA) was then synthesized. HRP catalyzes the oxidation of phenol groups to achieve the fast phenol crosslinking, and PVA-ACAC carbon radicals initiate the polymerization of MA groups simultaneously, finally obtaining the target PPQM gel. The quaternary ammonium and phenol groups endow the PPQM gel with excellent antibacterial and antioxidant properties, respectively. This multifunctional hydrogel, which has additional adhesive and hemostatic properties, could promote wound healing processes in an in vivo full-thickness skin defect experiment by reducing the generation of pro-inflammatory cytokines (IL-6) and upregulating anti-inflammatory factors (IL-10) and angiogenesis-related cytokines (VEGF and α-SMA). As a result, it could be used as competitive wound dressings.

Renewable marine polysaccharides for microenvironment-responsive wound healing

Marine polysaccharides (MPs) are an eco-friendly and renewable resource with a distinctive set of biological functions and are regarded as biological materials that can be in contact with tissues and body fluids for an extended time and promote tissue or organ regeneration. Skin tissue is easily invaded by the external environment due to its softness and large surface area. However, the body's natural physiological healing process is often too slow or suffers from the incomplete restoration of skin structure and function. Functional wound dressings are crucial for skin tissue engineering. Herein, popular MPs from different sources are summarized systematically. In particular, the structure-effectiveness of MP-based wound dressings and the physiological remodeling process of different wounds are reviewed in detail. Finally, the prospect of MP-based smart wound dressings is stated in conjunction with the wound microenvironment and provides new opportunities for high-value biomedical applications of MPs.

Chitosan functionalized bismuth oxychloride/zinc oxide nanocomposite for enhanced photocatalytic degradation of Congo red

The industrial discharge of dye pollutant contaminated wastewater is the major cause of water and soil pollution. Photocatalysis is a promising and green remediation technology, which has received widespread attention in the remediation of hazardous dyes from aqueous environment and convert them into harmless compounds. Herein, we report the synthesis of chitosan (CS) functionalized bismuth oxychloride/zinc oxide (BiOCl/ZnO) nanocomposite by a modified hydrothermal route. The physiochemical characterization revealed that the synthesized nanocomposite have crystalline, agglomerated spherical along with rod shaped morphology and size range from 35 to 160 nm. FTIR peaks at 825, 727, 662 and 622 cm^-1 specified the presence of BiO and ZnO bonds, whereas peak at 1635 cm^-1 revealed the existence of amine groups which confirms the presence of CS in the synthesized CS-BiOCl/ZnO nanocomposite. Catalytic property of synthesized nanocomposite was evaluated by the degradation of Congo red (CR) under UV-light irradiation. CR dye degradation percentage was found to be 93 % within a short period of 40 min by utilizing UV-light. Furthermore, reusability of CS-BiOCl/ZnO photocatalyst was also investigated, and it remained significant photocatalytic activity after three consecutive cycles. Hence, the results obtained in this study revealed that CS-BiOCl/ZnO nanocomposite can be used as a potential photocatalyst to remediate organic pollutants in various industries.

Enzymatically crosslinked hydrogel based on tyramine modified gelatin and sialylated chitosan

The enzymatically crosslinked hydrogel could replicate the cellular microenvironment for biomedical applications. In the present study, to improve the cytocompatibility of chitosan (CS), sialic acid (SA) was introduced to CS to synthesize sialylated CS (CS-SA), and the tyramine (TA) was grafted to gelatin (G) to obtain TA modified gelatin (G-TA). The successful synthesis of CS-SA and G-TA was confirmed using¹H NMR and UV-Vis absorption spectra. The interpenetrating polymer networks G-TA/CS-SA (GC) hydrogel was then fabricated via blending G-TA and CS-SA solutions and crosslinked using horseradish peroxidase. The storage modulus (G') of the fabricated GC hydrogels with different ratios of G-TA/CS-SA greatly varied during the formation and strain of hydrogels. With the increase of CS-SA concentration from 0% to 2%, the storage modulus of GC hydrogels was also observed to decrease from 1500 Pa to 101 Pa; the water uptake capacity of GC hydrogels increased from 1000% to 4500%. Additionally, the cell counting kit-8 and fluorescent images demonstrated the excellent cytocompatibility of GC hydrogels after culturing with NIH 3T3 cells. The obtained results indicated that the fabricated GC hydrogels might have potential in biomedical fields, such as wound dressing.

β-Glucan "Trained Immunity" Immunomodulatory Properties Potentiate Tissue Wound Management and Accelerate Fitness Recover

Introduction

It is well established that moderate physical activity can improve the immune status, rather excess or high-intensity physical exercise can cause damage to the immune system. In addition, muscle injuries resulting from increased frequency and intensity of exercises compromise innate immune activity and may decrease tissue regeneration. Thus, β-glucans, a natural compound, may represent an important substance with strong immunomodulatory properties acting as an immunostimulant therapy known as "trained immunity". This immune stimulating therapeutic is an immunological memory phenomenon linked to the innate immune system, triggering cellular changes at epigenetic, transcriptional, and functional levels, to regulate the immune system and recover its homeostasis with clinical benefits.

Conclusion

This narrative review works with the current evidence regarding β-glucans as a possible alternative therapy for wound healing and its safety and efficacy in the treatment of muscle injuries and physical recovery including other chronic conditions and diseases.

Gellan Gum in Wound Dressing Scaffolds

Several factors, such as bacterial infections, underlying conditions, malnutrition, obesity, ageing, and smoking are the most common issues that cause a delayed process of wound healing. Developing wound dressings that promote an accelerated wound healing process and skin regeneration is crucial. The properties of wound dressings that make them suitable for the acceleration of the wound healing process include good antibacterial efficacy, excellent biocompatibility, and non-toxicity, the ability to provide a moist environment, stimulating cell migration and adhesion, and providing gaseous permeation. Biopolymers have demonstrated features appropriate for the development of effective wound dressing scaffolds. Gellan gum is one of the biopolymers that has attracted great attention in biomedical applications. The wound dressing materials fabricated from gellan gum possess outstanding properties when compared to traditional dressings, such as good biocompatibility, biodegradability, non-toxicity, renewability, and stable nature. This biopolymer has been broadly employed for the development of wound dressing scaffolds in different forms. This review discusses the physicochemical and biological properties of gellan gum-based scaffolds in the management of wounds.

Polysaccharide-based nanocomposites for biomedical applications: a critical review

Polysaccharides (PSA) have taken specific position among biomaterials for advanced applications in medicine. Nevertheless, poor mechanical properties are known as the main drawback of PSA, which highlights the need for PSA modification. Nanocomposites PSA (NPSA) are a class of biomaterials widely used as biomedical platforms, but despite their importance and worldwide use, they have not been reviewed. Herein, we critically reviewed the application of NPSA by categorizing them into generic and advanced application realms. First, the application of NPSA as drug and gene delivery systems, along with their role in the field as an antibacterial platform and hemostasis agent is discussed. Then, applications of NPSA for skin, bone, nerve, and cartilage tissue engineering are highlighted, followed by cell encapsulation and more critically cancer diagnosis and treatment potentials. In particular, three features of investigations are devoted to cancer therapy, i.e., radiotherapy, immunotherapy, and photothermal therapy, are comprehensively reviewed and discussed. Since this field is at an early stage of maturity, some other aspects such as bioimaging and biosensing are reviewed in order to give an idea of potential applications of NPSA for future developments, providing support for clinical applications. It is well-documented that using nanoparticles/nanomaterials above a critical concentration brings about concerns of toxicity; thus, their effect on cellular interactions would become critical. We compared nanoparticles used in the fabrication of NPSA in terms of toxicity mechanism to shed more light on future challenging aspects of NPSA development. Indeed, the neutralization mechanisms underlying the cytotoxicity of nanomaterials, which are expected to be induced by PSA introduction, should be taken into account for future investigations.

Development of guar gum-based dual-layer wound dressing containing Lactobacillus plantarum: Rapid recovery and mechanically flexibility

This study aimed to develop a Lactobacillus plantarum (L. plantarum)-loaded dual-layer wound dressing (DLD) with excellent wound recovery and mechanical properties. L. plantarum-loaded DLD was fabricated by covering the hydrogel (inner layer) with a hydrocolloid (external layer). The hydrocolloid was manufactured by the hot-melt method, consisting of liquid paraffin, polyisobutylene, styrene-isoprene-styrene, and sodium carboxymethylcellulose (12:20:25:43, w/w/w/w). In contrast, the hydrogel was fabricated by the freeze-and-thaw method to load heat-labile L. plantarum. Various non-ionic materials have been investigated to select appropriate hydrogel components. The hydrogel composed of L. plantarum stock solution, guar gum, and polyvinyl alcohol (10:2:10, w/w/w) was chosen for its excellent swelling capacity and mechanical properties. As a result, heat-labile L. plantarum was successfully loaded into the guar-gum-based DLD. Moreover, guar gum-based DLD containing L. plantarum exhibited significantly enhanced swelling capacity and elasticity compared to single hydrogel layer (swelling capacity: DLD, 920.7 ± 32.4 % vs. hydrogel, 282.2 ± 6.5 %; elastic modulus: DLD, 2.9 ± 0.3 × 10^-3 N/mm² vs. hydrogel, 4.2. ± 0.7 × 10^-3 N/mm²). The wound recovery test using Pseudomonas aeruginosa-infected animal model and histological profiles confirmed guar gum-based DLD containing L. plantarum to elicit accelerated wound recovery with complete re-epithelialization compared to commercial product and non-treated (recovery rate at Day 3: DLD, 67.8 ± 6.2 % vs. commercial product, 30.4 ± 11.7 % vs. non-treated, 14.2 ± 7.5 %). Therefore, L. plantarum-loaded DLD is an effective system for wound treatment.

Synthesis of silver/Fe3O4@chitosan@polyvinyl alcohol magnetic nanoparticles as an antibacterial agent for accelerating wound healing

Bacterial infection causes wound inflammation and slows wound healing, posing a great threat to human health, which needs to explore more antibacterial nanobiomaterials to promote wound healing. Therefore, this study was conducted to develop low-cost silver/Fe₃O₄@Chitosan@polyvinyl alcohol (Ag/Fe₃O₄@CS@PVA) via a one-pot method to promote healing in bacteria-infected wounds. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM) confirmed that Ag/Fe₃O₄@CS@PVA was successfully prepared. In vitro antibacterial experiments demonstrated strong antibacterial activity of Ag/Fe₃O₄@CS@PVA against Escherichia coli and Staphylococcus aureus. The Ag/Fe₃O₄@CS@PVA destroyed the bacterial cell membrane or internal structure, thus resulting in cell death for antibacterial effects. Cytotoxicity and hemolysis rate tests showed that Ag/Fe₃O₄@CS@PVA posed fine biocompatibility. In addition, in vivo assays confirmed that Ag/Fe₃O₄@CS@PVA not only promoted the healing of wound infection caused by bacteria, but also had no toxic effect on mouse organs. Therefore, the low-cost Ag/Fe₃O₄@CS@PVA nanocomposites have great potential in controlling 'bacterial' pathogen.

Borrowing the Features of Biopolymers for Emerging Wound Healing Dressings: A Review

Wound dressing design is a dynamic and rapidly growing field of the medical wound-care market worldwide. Advances in technology have resulted in the development of a wide range of wound dressings that treat different types of wounds by targeting the four phases of healing. The ideal wound dressing should perform rapid healing; preserve the body’s water content; be oxygen permeable, non-adherent on the wound and hypoallergenic; and provide a barrier against external contaminants—at a reasonable cost and with minimal inconvenience to the patient. Therefore, choosing the best dressing should be based on what the wound needs and what the dressing does to achieve complete regeneration and restoration of the skin’s structure and function. Biopolymers, such as alginate (ALG), chitosan (Cs), collagen (Col), hyaluronic acid (HA) and silk fibroin (SF), are extensively used in wound management due to their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body. However, most of the formulations based on biopolymers still show various issues; thus, strategies to combine them with molecular biology approaches represent the future of wound healing. Therefore, this article provides an overview of biopolymers’ roles in wound physiology as a perspective on the development of a new generation of enhanced, naturally inspired, smart wound dressings based on blood products, stem cells and growth factors.