Recent advancements in biopolymer and metal nanoparticle-based materials in diabetic wound healing management

Poly(lactic-co-glycolic acid)-Chitosan-Gelatin Composite Nanomaterials for the Treatment of Diabetic Foot Ulcer Wound Infection

In this experiment, a solid carrier was prepared with PLGA, gelatin, and chitosan as the main raw materials, so that BMSCs could exert their repairing effect directly in the ulcer area under the stimulation of Klotho protein. We chose to use electrospun PLGA as the main technical means to provide suitable adhesion growth environment for BMSCs by preparing PLGA nanofibers. At the same time, PLGA nanofibers are also a controlled release material, so that Klotho protein can remain active, thereby achieving the purpose of stimulating BMSCs for a long time. Through the nano-scale porous structure provided on the surface of the PLGA film, BMSCs can adhere well to the surface of the material and continuously receive stimulation from the inner Klotho protein. We applied this composite to mice with diabetic ulcers, and verified the effects of Klotho protein and BMSCs on DFU healing in five groups of mice. From the results, the Klotho+BMSCs group achieved the best healing effect, followed by the Klotho group alone, while the other three groups had no significant difference in healing effects. It is proved that both Klotho and BMSCs can help the healing of diabetic ulcers, but BMSCs alone cannot survive in harsh environments, and it is difficult to play a normal repair role. The purpose of this study was to investigate the effect of Klotho protein on BMSCs and ECs under high glucose conditions, and to find a suitable carrier for planting BMSCs on it. At the same time, the material also has a certain sustained release function. We have concluded that Klotho protein can promote the proliferation and migration of BMSCs and ECs under high glucose conditions. When combined with electrospinning technology to prepare a protein that can release Klotho, it also provides a microstructure suitable for BMSCs adhesion, thereby ensuring that BMSCs can successfully survive. In the end, we artificial Klotho protein can promote angiogenesis in diabetic ulcer areas by protecting BMSCs and ECs, thereby promoting healing of ulcer areas.

Experimental Study on the Effect of Allogeneic Endothelial Progenitor Cells on Wound Healing in Diabetic Mice

Endothelial progenitor cells (EPCs) are involved in the neovascularization in traumatic and ischemic sites, but EPCs are "detained" in bone marrow under diabetic conditions, which results in reduction of the number of EPCs and their biological activity in peripheral blood. Based on our previous study to mobilize autologous bone marrow EPCs by administering AMD3100+G-CSF to realize the optimal effect, our present study is aimed at exploring the effects of transplanting EPCs locally in a wound model of diabetic mice. First, we prepared and identified EPCs, and the biological functions and molecular characteristics were compared between EPCs from DB/+ and DB/DB mice. Then, we performed full-thickness skin resection in DB/DB mice and tested the effect of local transplantation of EPCs on skin wound healing. The wound healing process was recorded using digital photographs. The animals were sacrificed on postoperative days 7, 14, and 17 for histological and molecular analysis. Our results showed that DB/+ EPCs were biologically more active than those of DB/DB EPCs. When compared with the control group, local transplantation of EPCs accelerated wound healing in DB/DB mice by promoting wound granulation tissue formation, angiogenesis, and collagen fiber deposition, but there was no significant difference in wound healing between DB/+ EPCs and DB/DB EPCs transplanted into the wound. Furthermore, local transplantation of EPCs promoted the expression of SDF-1, CXCR4, and VEGF. We speculated that EPC transplantation may promote wound healing through the SDF-1/CXCR4 axis. This point is worth exploring further. Present data are of considerable significance because they raise the possibility of promoting wound healing by isolating autologous EPCs from the patient, which provides a new approach for the clinical treatment of diabetic wounds in the future.

Effective antibacterial electrospun cellulose acetate nanofibrous patches containing chitosan/erythromycin nanoparticles

Herein, we fabricated the antibacterial nanofibrous mats composed of cellulose acetate (CA) nanofibers loaded with erythromycin-chitosan nanoparticles (Ery-CS NPs) intended for infected wound dressing. The Ery-loaded CS NPs were prepared by ionic gelation process and then incorporated into the CA electrospun nanofibers (NFs). Regarding physiochemical properties, the NPs and obtained mats were characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM), attenuated total reflection fourier transform infrared (ATR-FTIR), and contact angle measurement. The antimicrobial activity and cell viability of fibroblast cells were also evaluated. The results indicated that Ery was loaded into CS NPs with high encapsulation efficiency (95%). The CA NFs (17% w/v) incorporated with the Ery-CS NPs (12 wt%) displayed smooth homogenous morphology with 141.7 ± 91.7 nm average diameter. The relevant analyses confirmed that the NPs incorporated into NFs and provided high water holding capacity with high porosity. Finally, Ery-CS NPs/CA mats were able to inhibit the growth of both Gram-positive and Gram-negative bacteria as well as showed no cytotoxic effect on the human dermal fibroblast cells. Overall, our findings concluded that the proposed system could be potentially applied as the proper antibacterial mats for infected wound dressing applications.

Potential Applications of Nanomaterials and Technology for Diabetic Wound Healing

Diabetic wound shows delayed and incomplete healing processes, which in turn exposes patients to an environment with a high risk of infection. This article has summarized current developments of nanoparticles/hydrogels and nanotechnology used for promoting the wound healing process in either diabetic animal models or patients with diabetes mellitus. These nanoparticles/hydrogels promote diabetic wound healing by loading bioactive molecules (such as growth factors, genes, proteins/peptides, stem cells/exosomes, etc.) and non-bioactive substances (metal ions, oxygen, nitric oxide, etc.). Among them, smart hydrogels (a very promising method for loading many types of bioactive components) are currently favored by researchers. In addition, nanoparticles/hydrogels can be combined with some technology (including PTT, LBL self-assembly technique and 3D-printing technology) to treat diabetic wound repair. By reviewing the recent literatures, we also proposed new strategies for improving multifunctional treatment of diabetic wounds in the future.

Synergistic Nanocomposites of Different Antibiotics Coupled with Green Synthesized Chitosan-Based Silver Nanoparticles: Characterization, Antibacterial, in vivo Toxicological and Biodistribution Studies

Purpose

The present study reports chitosan functionalized green synthesized CS-AgNPs, conjugated with amoxicillin (AMX), cefixime (CEF), and levofloxacin (LVX) for safe and enhanced antibacterial activity.

Methods

The CS-AgNPs and conjugates CS-AgNPs+AMX CS-AgNPs+CEF, and CS-AgNPs+LVX were characterized by UV–Vis, FTIR, SEM, TEM, EDX spectroscopy. The size distribution and zeta potential were measured using the dynamic light scattering (DLS) technique. The interaction between CS-AgNPs and antibiotic molecules was also investigated using UV–Vis spectroscopy at the concentrations of 5, 50, 500, and 5000 µM for each antibiotic. Antibacterial activity and synergism were assessed by the Fractional Inhibitory Concentration (FIC) index. The mechanism for synergistic activity was investigated by the detection of hydroxyl species based on the chemiluminescence of luminol. The biocompatibility index (BI) was calculated from IC₅₀ using the HeLa cell line. In vivo toxicity and tissue distribution of silver ions were evaluated on Sprague Dawley rats. Physical interactions of antibiotics and significant (P<0.05) antibacterial activity were observed after loading on CS-AgNPs surfaces.

Results

The spherical shape nanocomposites of CS-AgNPs with different antibiotics were prepared with mean size ranges of 80–120 nm. IC₅₀ of antibiotics-conjugated CS-AgNPs decreased compared to CS-AgNPs. The biocompatibility (BI) index showed that antibiotics-conjugated CS-AgNPs have high antibacterial potential and low toxicity. Highly significant (P<0.005) increase in the generation of hydroxyl species indicated the radical scavenging mechanism for synergistic activity of CS-AgNPs after combined with different antibiotics. Biochemical analysis and histopathological examinations confirmed low toxicity with minor hepatotoxicity at higher doses. After oral administration, extensive distribution of Ag ion was observed in spleen and liver.

Conclusion

The study demonstrates positive attributes of antibiotics-conjugated CS-AgNPs, as a promising antibacterial agent with low toxicity.

Nanotechnology-driven advances in the treatment of diabetic wounds

Diabetic foot ulcers (DFUs) are chronic severe complications of diabetes disease and remain a worldwide clinical challenge with social and economic consequences. Diabetic wounds can cause infection, amputation of lower extremities, and even death. Several factors including impaired angiogenesis, vascular insufficiency, and bacterial infections result in a delayed process of wound healing in diabetic patients. Treatment of wound infections using traditional antibiotics has become a critical status. Thus, finding new therapeutic strategies to manage diabetic wounds is urgently needed. Nanotechnology has emerged as an efficient approach for this purpose. This review aimed to summarize recent advances using nanotechnology for the treatment of diabetic wounds.

Manuka honey and bioactive glass impart methylcellulose foams with antibacterial effects for wound-healing applications

Wound dressings able to deliver topically bioactive molecules represent a new generation of wound-regeneration therapies. In this article, foams based on methylcellulose cross-linked with Manuka honey were used as a platform to deliver borate bioactive glass particles doped additionally with copper. Borate bioactive glasses are of great interest in wound-healing applications due to a combination of favorable features, such as angiogenic and antibacterial properties. The multifunctional composite providing the dual effect of the bioactive glass and Manuka honey was produced by freeze-drying, and the resulting foams exhibit suitable morphology characterized by high porosity. Moreover, the performed tests showed improved wettability and mechanical performance with the addition of bioactive glass particles. Dissolution studies using simulated body fluid and cell biology tests using relevant skin cells further proved the excellent bioactivity and positive effects of the foams on cell proliferation and migration. Most interestingly, by the dual release of Manuka honey and ions from the copper-doped bioactive glass, an antibacterial effect against E. coli and S. aureus was achieved. Therefore, the multifunctional foams showed promising outcomes as potential wound dressings for the treatment of infected wounds.

Umbilical Cord-Derived Mesenchymal Stem Cell-Derived Exosomes Combined Pluronic F127 Hydrogel Promote Chronic Diabetic Wound Healing and Complete Skin Regeneration

Purpose

Chronic refractory wounds are a multifactorial comorbidity of diabetes mellitus with the characteristic of impaired vascular networks. Currently, there is a lack of effective treatments for such wounds. Various types of mesenchymal stem cell-derived exosomes (MSC-exos) have been shown to exert multiple therapeutic effects on skin regeneration. We aimed to determine whether a constructed combination of human umbilical cord MSC (hUCMSC)-derived exosomes (hUCMSC-exos) and Pluronic F-127 (PF-127) hydrogel could improve wound healing.

Materials and Methods

We topically applied human umbilical cord-derived MSC (hUCMSC)-derived exosomes (hUCMSC-exos) encapsulated in a thermosensitive PF-127 hydrogel to a full-thickness cutaneous wound in a streptozotocin-induced diabetic rat model. The material properties and wound healing ability of the hydrogel and cellular responses were analyzed.

Results

Compared with hUCMSC-exos, PF-127-only or control treatment, the combination of PF-127 and hUCMSC-exos resulted in a significantly accelerated wound closure rate, increased expression of CD31 and Ki67, enhanced regeneration of granulation tissue and upregulated expression of vascular endothelial growth factor (VEGF) and factor transforming growth factor beta-1 (TGFβ-1).

Conclusion

The efficient delivery of hUCMSC-exos in PF-127 gel and improved exosome ability could promote diabetic wound healing. Thus, this biomaterial-based exosome therapy may represent a new therapeutic approach for cutaneous regeneration of chronic wounds.

Innovations in Infection Prevention and Treatment

Background: Patients with large, acute burn injuries are a major challenge for clinicians. The loss of skin barrier protection against micro-organisms combined with the induced immunosuppression after burn injury makes this population especially vulnerable to infection. For burn-injured patients who survive immediate management considerations and burn resuscitation after acute injury, sepsis remains the primary cause of death. The purpose of this article is to describe current strategies and innovations in burn sepsis prevention and management. Methods: This work reviews the current understanding of the systemic inflammatory response to burn injury and burn sepsis as well as current strategies in insolation and infection prevention, newer burn unit design strategies in the context of infection prevention, and novel therapies being considered in topical antimicrobial wound care management. Results: A review of burn sepsis is key to understanding current paradigms and innovation in burn management and prevention. Key management principles begin from the time of injury and persist throughout the patient's hospital course. This includes use of personal protective equipment, burn unit design considerations, and knowledge of critical care principles such as central venous catheter management strategies. Innovations on wound dressing types, forms, and use have been key to better controlling burn wound sepsis and improving wound healing. Products incorporating nanotechnology, novel anions, oxygen, and even light have been key to introducing previously unconsidered methods to fight or prevent infection. Conclusion: Understanding the pathophysiology and source identification of sepsis from burn wounds has been a key contributor in developing innovative prevention and therapeutic strategies in burn management. The emergence of drug-resistant pathogens and the difficulty of systemic antibiotic agents to reach poorly vascularized wounds have further reinforced the need to anticipate management strategies moving forward. A proactive, multidisciplinary approach is necessary to minimize the morbidity and mortality associated with infection control.

Production of a novel poly(ɛ-caprolactone)-methylcellulose electrospun wound dressing by incorporating bioactive glass and Manuka honey

Wound dressings produced by electrospinning exhibit a fibrous structure close to the one of the extracellular matrix of the skin. In this article, electrospinning was used to fabricate fiber mats based on the well-known biopolymers poly(ɛ-caprolactone) (PCL) and methylcellulose (MC) using benign solvents. The blend fiber mats were cross-linked using Manuka honey and additionally used as a biodegradable platform to deliver bioactive glass particles. It was hypothesized that a dual therapeutic effect can be achieved by combining Manuka honey and bioactive glass. Morphological and chemical examinations confirmed the successful production of submicrometric PCL-MC fiber mats containing Manuka honey and bioactive glass particles. The multifunctional fiber mats exhibited improved wettability and suitable mechanical properties (ultimate tensile strength of 3-5 MPa). By performing dissolution tests using simulated body fluid, the improved bioactivity of the fiber mats by the addition of bioactive glass was confirmed. Additionally, cell biology tests using human dermal fibroblasts and human keratinocytes-like HaCaT cells showed the potential of the fabricated composite fiber mats to be used as wound dressing, specially due to the ability to support wound closure influenced by the presence of bioactive glass. Moreover, based on the results of the antibacterial tests, it is apparent that an optimization of the electrospun fiber mats is required to develop suitable wound dressing for the treatment of infected wounds.

Novel Nanocarriers for the Treatment of Wound Healing

The sequence of biochemical and cellular responses restoring the integrity of the subcutaneous tissue of the skin is termed as wound healing. Inflammatory cytokine suppression and inflammatory transduction cascades are the major targets for wound healing. Formulations for wound healing should promote neovascularization and angiogenic pathways by increasing the expression of vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor. Medication used for wound healing promotes antiinflammatory associated with anti-bacterial action. In order to boost the effectiveness of current medical treatments, the cutting-edge nanotechnology offers many novel therapies. This review summarized and discussed wound healing, types of wounds, natural materials used for wound healing, metallic nanoparticles and current nano drug delivery systems used for wound healing with special emphasis on the angiogenesis role in the healing of wounds.

Biosynthesis, Characterization, and Wound-Healing Activity of Phenytoin-Loaded Copper Nanoparticles

Wound-healing is a very complex and evolutionary process that involves a great variety of dynamic steps. Although different pharmaceutical agents have been developed to hasten the wound-healing process, the existing agents are still far from optimal. The present work aimed to prepare and evaluate the wound-healing efficacy of phenytoin-loaded copper nanoparticles (PHT-loaded CuNPs). CuNPs were biosynthesized using licorice aqueous extract. The prepared CuNPs were loaded with PHT by adsorption, characterized, and evaluated for wound-healing efficiency. Results showed that both plain and PHT-loaded CuNPs were monodisperse and exhibited a cubic and hexagonal morphology. The mechanism by which PHT was adsorbed on the surface of CuNPs was best fit by the Langmuir model with a maximum loaded monolayer capacity of 181 mg/g. The kinetic study revealed that the adsorption reaction followed the pseudo-second order while the thermodynamic parameters indicated that the adsorption process was physical in nature and endothermic, and occurred spontaneously. Moreover, the in vivo wound-healing activity of PHT-loaded CuNP impregnated hydroxypropylmethyl cellulose (HPMC) gel was carried out using an excisional wound model in rats. Data showed that PHT-loaded CuNPs accelerated epidermal regeneration and stimulated granulation and tissue formation in treated rats compared to controls. Additionally, quantitative real-time polymerase chain reaction (RT-PCR) analysis showed that lesions treated with PHT-loaded CuNPs were associated with a marked increase in the expression of dermal procollagen type I and a decrease in the expression of the inflammatory JAK3 compared to control samples. In conclusion, PHT-loaded CuNPs are a promising platform for effective and rapid wound-healing.

Effect of Cord Blood Platelet Gel on wound healing capacity of human Mesenchymal Stromal Cells

BACKGROUND

Wound healing is a dynamic process, involving the recruitment of growth factors, cytokines, chemokines and cellular populations. Recently, the Cord Blood Platelet Gel (CBPG) has been applied successfully in wound closure and tissue regeneration. Moreover, its proper combination with stem cell populations such as Mesenchymal Stromal Cells (MSCs) may positively improve the wound healing process. Based on the above data, this study aimed to the evaluation of wound healing capacity of MSCs combined with CBPG under in vitro conditions.

METHODS

Initially, CBPG was developed from Cord Blood Units (CBUs). The determination of wound healing ability of MSCs was performed using the scratch wound assay. In addition, the morphological features, immunophenotypical characteristics and differentiation capacity of MSCs were evaluated.

RESULTS

Scratch wound assay results showed, that CBPG could positively stimulate the MSCs migration. Moreover, MSCs cultured in presence of CBPG were characterized by elongated shape and improved stemness properties as it was indicated by flow cytometric analysis and differentiation process.

CONCLUSION

These results clearly showed the beneficial effect of CBPG in combination with MSCs in wound healing. The proper combination of CBPG with stem cells strategy may enhance the healing process in patients with skin erosions.

Recent Advances in Nanomaterial-Based Wound-Healing Therapeutics

Nanomaterial-based wound healing has tremendous potential for treating and preventing wound infections with its multiple benefits compared with traditional treatment approaches. In this regard, the physiochemical properties of nanomaterials enable researchers to conduct extensive studies on wound-healing applications. Nonetheless, issues concerning the use of nanomaterials in accelerating the efficacy of existing medical treatments remain unresolved. The present review highlights novel approaches focusing on the recent innovative strategies for wound healing and infection controls based on nanomaterials, including nanoparticles, nanocomposites, and scaffolds, which are elucidated in detail. In addition, the efficacy of nanomaterials as carriers for therapeutic agents associated with wound-healing applications has been addressed. Finally, nanomaterial-based scaffolds and their premise for future studies have been described. We believe that the in-depth analytical review, future insights, and potential challenges described herein will provide researchers an up-to-date reference on the use of nanomedicine and its innovative approaches that can enhance wound-healing applications.

Antibacterial, anticoagulant and cytotoxic evaluation of biocompatible nanocomposite of chitosan loaded green synthesized bioinspired silver nanoparticles

Present work reports the green synthesis of chitosan functionalized silver nanoparticles (CS-AgNPs) using ethanolic buds extract of Sygyzium aromaticum. CS-AgNPs were characterized physically, evaluated for antibacterial, anticoagulant and antiplatelet activities, and toxicity profile. The physical characterization of CS-AgNPs was done by UV/vis, SEM, TEM, FTIR and EDX. The sphericity was found uniform. FTIR and EXD showed noninterfering few impurities. The antibacterial activity against VRSA (ZI, 23.2 ± 0.51 mm) and MRSA (ZI, 25.8 ± 0.32 mm) were determined. The rise in bleeding and thromboplastin was observed highly significant while increased in prothrombin and activated partial prothrombin time in significant manner at both the doses of CS-AgNPs (0.025 mg/kg and 0.05 mg/kg). Reduction in the levels of fibrinogen was also highly significant. Platelet aggregation decreased at high dose of CS-AgNPs i.e. 55.14 ± 8.25% (arachidonic acid) and 13.06 ± 2.17% (collagen). Thrombin antithrombin (TAT) complex activity was found highest for CS-AgNPs. Cytotoxicity was assessed using HeLa cell lines (LC₅₀; 125 μg/ml) and brine shrimp lethality tests (LC_50; 518 μg/ml). The work suggests that green synthesized chitosan functionalized silver nanoparticles may be utilized as an effective antibacterial agent and anticoagulant with low toxicity. The current findings will open a new window for nanomedicine development and future clinical application.

Incorporation of metal-organic frameworks into electrospun chitosan/poly (vinyl alcohol) nanofibrous membrane with enhanced antibacterial activity for wound dressing application

Developing wound dressing that inhibits bacterial infection for treating complex wound healing processes has been a research hotspot. Here, we report the fabrication of Cu-MOFs (HKUST-1) incorporated electrospun chitosan/polyvinyl alcohol (HKUST-1/chitosan/PVA) fibers through the blending electrospinning for wound therapy. HKUST-1/chitosan/PVA fibers displayed satisfying physical properties, such as mechanical property, water uptake, water vapor transmission rate, etc. Cytotoxicity test indicated that HKUST-1/chitosan/PVA fibers were biocompatible and could support cell adhesion. Due to the HKUST-1 incorporation, HKUST-1/chitosan/PVA fibers exhibited the good antibacterial activity against Escherichia coli and Staphylococcus aureus with 99% antibacterial efficiency. Furthermore, in animal studies, compared with commercial chitosan dressings and chitosan/PVA fibers, HKUST-1/chitosan/PVA fibers were more efficient to heal the wound with less inflammation. In summary, the HKUST-1/chitosan/PVA fibers with good physicochemical property, biocompatibility and antibacterial property is an excellent wound dressing for full-thickness skin repair.

Novel Drug Delivery Systems for Loading of Natural Plant Extracts and Their Biomedical Applications

Many types of research have distinctly addressed the efficacy of natural plant metabolites used for human consumption both in cell culture and preclinical animal model systems. However, these in vitro and in vivo effects have not been able to be translated for clinical use because of several factors such as inefficient systemic delivery and bioavailability of promising agents that significantly contribute to this disconnection. Over the past decades, extraordinary advances have been made successfully on the development of novel drug delivery systems for encapsulation of plant active metabolites including organic, inorganic and hybrid nanoparticles. The advanced formulas are confirmed to have extraordinary benefits over conventional and previously used systems in the manner of solubility, bioavailability, toxicity, pharmacological activity, stability, distribution, sustained delivery, and both physical and chemical degradation. The current review highlights the development of novel nanocarrier for plant active compounds, their method of preparation, type of active ingredients, and their biomedical applications.

Silver nanoparticles: Advanced and promising technology in diabetic wound therapy

Wounds associated with diabetes mellitus are the most severe co-morbidities, which could be progressed to cause cell necrosis leading to amputation. Statistics on the recent status of the diabetic wounds revealed that the disease affects 15% of diabetic patients, where 20% of them undergo amputation of their limb. Conventional therapies are found to be ineffective due to changes in the molecular architecture of the injured area, urging novel deliveries for effective treatment. Therefore, recent researches are on the development of new and effective wound care materials. Literature is evident in providing potential tools in topical drug delivery for wound healing under the umbrella of nanotechnology, where nano-scaffolds and nanofibers have shown promising results. The nano-sized particles are also known to promote healing of wounds by facilitating proper movement through the healing phases. To date, focuses have been made on the efficacy of silver nanoparticles (AgNPs) in treating the diabetic wound, where these nanoparticles are known to exploit potential biological properties in producing anti-inflammatory and antibacterial activities. AgNPs are also known to activate cellular mechanisms towards the healing of chronic wounds; however, associated toxicities of AgNPs are of great concern. This review is an attempt to illustrate the use of AgNPs in wound healing to facilitate this delivery system in bringing into clinical applications for a superior dressing and treatment over wounds and ulcers in diabetes patients.

Electrospun Nanocomposites Containing Cellulose and Its Derivatives Modified with Specialized Biomolecules for an Enhanced Wound Healing

Wound healing requires careful, directed, and effective therapies to prevent infections and accelerate tissue regeneration. In light of these demands, active biomolecules with antibacterial properties and/or healing capacities have been functionalized onto nanostructured polymeric dressings and their synergistic effect examined. In this work, various antibiotics, nanoparticles, and natural extract-derived products that were used in association with electrospun nanocomposites containing cellulose, cellulose acetate and different types of nanocellulose (cellulose nanocrystals, cellulose nanofibrils, and bacterial cellulose) have been reviewed. Renewable, natural-origin compounds are gaining more relevance each day as potential alternatives to synthetic materials, since the former undesirable footprints in biomedicine, the environment, and the ecosystems are reaching concerning levels. Therefore, cellulose and its derivatives have been the object of numerous biomedical studies, in which their biocompatibility, biodegradability, and, most importantly, sustainability and abundance, have been determinant. A complete overview of the recently produced cellulose-containing nanofibrous meshes for wound healing applications was provided. Moreover, the current challenges that are faced by cellulose acetate- and nanocellulose-containing wound dressing formulations, processed by electrospinning, were also enumerated.

Transparent chitosan based nanobiocomposite hydrogel: Synthesis, thermophysical characterization, cell adhesion and viability assay

This study designed to explore the characteristic features of the novel prepared hydrogel. This transparent nanocomposite hydrogel was formulated with employing environmental friendly biopolymer, "chitosan". To increase the hydrophilicity of chitosan, it was quaternized with triethyl amine. Also by incorporating click protocol, the triazole rings were inserted in the structure. After decoration with appropriate chemicals using efficient methods, functionalized chitosan and the corresponding hydrogel were investigated by Fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and dynamic-mechanical thermal analysis (DMTA). Swelling behavior of the synthesized hydrogel was assayed in both room temperature and 37 °C. Moreover, swelling kinetics were appraised and found that the experimental data fit the Schott's equation. To study the cell adhesion and proliferation, MTT assay was performed and the SEM images of 24, 48 and 72 h of direct cell culture on the surface of the scaffold were obtained. Morphological features of cultured cells were confirmed with Giemsa staining. The results displayed the potential capability of the synthesized scaffold for being used in bioapplications.

Preparation, characterization and evaluation of a new film based on chitosan, arginine and gold nanoparticle derivatives for wound-healing efficacy

It is well-known that the combination of polymers and nanoparticles (NPs) provides optimised wound dressing and accelerates wound healing. The knowledge about the structure and properties of these materials is of critical importance in biological processes related to wound healing. In this study, we prepared a chitosan (CS) film modified with arginine (Arg) and gold NPs (AuNPs) and investigated its effectiveness as a dressing material for wound healing. Fourier-transform infrared spectroscopy (FTIR) confirmed that Arg was successfully grafted on CS. The resultant CS-Arg/AuNP film was then characterised by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The modification of Arg and AuNPs improved the hydrophilicity, mechanical strength and antibacterial properties of the film, which in turn provided an enhanced ideal environment for cell adhesion and proliferation. Cell Counting Kit-8 (CCK-8) was used to demonstrate the survival rate. Furthermore, the proteins involved in wound healing were evaluated qualitatively and quantitatively by immunofluorescence and western blotting, respectively. The skin defect models used for the in vivo studies revealed that the CS-Arg/AuNP dressing accelerated wound closure, re-epithelialization and collagen deposition. Our cumulative findings support the feasibility of using the proposed film as a promising candidate for tissue engineering of the skin in the near future.

It is well-known that the combination of polymers and nanoparticles (NPs) provides optimised wound dressing and accelerates wound healing.

Bioactive Medications for the Delivery of Platelet Derivatives to Skin Wounds

Chronic wounds are the result of alterations in the complex series of events of physiological wound healing. In particular, the prolonged inflammation results in increased protease activity, in the deg-radation of extracellular matrix (ECM) and of growth factors (GFs). The relevance of platelet GFs in maintaining and restoring the complex equilibrium of different moments in wound healing is well recog-nized. Moreover, the observed decrease of their levels in chronic wounds suggested a possible therapeutic role of the external application to the wounds. It has been also pointed out that tissue regeneration can be more efficiently obtained by the synergic use of different GFs. Platelet derivatives such as platelet-rich plasma (PRP) and platelet lysate (PL) are able to release GFs in a balanced pool. Their therapeutic use in regenerative medicine and wound healing has been therefore more and more frequently proposed in clini-cal trials and in the literature. The development of a suitable formulation able to control the GFs release rate, to protect the GFs, and to assure their prolonged contact with the wound site, is of paramount im-portance for the therapeutic success. The present review considers some formulation approaches for PRP and PL application to wounds

Antibacterial and antioxidant assessment of cellulose acetate/polycaprolactone nanofibrous mats impregnated with propolis

Cellulose acetate (CA) electrospun nanofibers are one of the most practical cellulosic material which normally applied as carriers for drug delivery and wound healing systems. In this study, CA and polycaprolactone (PCL) was applied to fabricate the electrospun nanofibrous for wound dressing application. Propolis is a resin-like macromolecule produced by honeybees from the buds and diverse plants. Among many applications of this macromolecule, it has been occasionally employed directly to the skin for wound healing applications. Herein, owing to the significance of propolis, CA/PCL nanofibers were impregnated with a propolis-extracted solution to reach antibacterial and antioxidant mat. The scanning electron microscopy (SEM) images revealed that electrospinning of 10% (w/w) CA along with 14% (w/w) PCL produced excellent nanofibers compared to the resultant nanofibers. Hydrophobicity/hydrophilicity nature of CA/PCL mats was measured using water contact-angle method before and after treatment with NaOH. The nanofibrous mats exhibited a high water absorption capacity of about 400%. Antioxidant effect was measured by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay and propolis-CA/PCL presented a high antioxidant activity. Additionally, propolis-CA/PCL mats showed antibacterial activity against both the Gram-positive and Gram-negative bacteria. In conclusion, our results have confirmed that the propolis-impregnated CA/PCL mats have provided an appropriate surface for wound healing system.

Antimicrobial Silver Nanoparticles for Wound Healing Application: Progress and Future Trends

Recent data have reported that the burden of infections related to antibiotic-resistant bacteria in the European Union and European Economic Area (EEA) can be estimated as the cumulative burden of tuberculosis, influenza, and human immunodeficiency virus (HIV). In wound management, the control of infections represents a crucial issue and a multi-billion dollar industry worldwide. For diabetic wounds ulcers, in particular, infections are related to the majority of amputations in diabetic patients, which today represent an increasing number of the elderly. The greatest barrier to healing is represented by the biofilm, an organized consortium of bacteria encapsulated in a self-produced extracellular polymeric substance with high resistance to conventional antimicrobial therapies. There is an urgent need for novel anti-biofilm strategies and novel antimicrobial agents and, in this scenario, silver nanotechnology has received tremendous attention in recent years in therapeutically enhanced healthcare. Due to its intrinsic therapeutic properties and the broad-spectrum antimicrobial efficacy, silver nanoparticles have opened new horizons towards novel approaches in the control of infections in wound healing. This review aims at providing the reader with an overview of the most recent progress in silver nanotechnology, with a special focus on the role of silver in the wound healing process.

Biopolymer-based biomaterials for accelerated diabetic wound healing: A critical review

Non-healing, chronic wounds place a huge burden on healthcare systems as well as individual patients. These chronic wounds especially diabetic wounds will ultimately lead to compromised mobility, amputation of limbs and even death. Currently, wounds and limb ulcers associated with diabetes remain significant health issues; the associated healthcare cost ultimately leads to the increased clinical burden. The presence of diabetes interrupts a highly coordinated cascade of events in the wound closure process. Advances in the understanding of pathophysiological conditions associated with diabetic wounds lead to the development of drug delivery systems which can enhance wound healing by targeting various phases of the impaired processes. Wound environments typically contain degradative enzymes, along with an elevated pH and demonstrate a physiological cascade involved in the regeneration of tissue, which requires the application of an effective delivery system. This article aims to review the pathophysiological conditions associated with chronic and diabetic wounds. The delivery systems, involved in their treatment are described, highlighting potential biomaterials and polymers for establishing drug delivery systems, specifically for the treatment of diabetic wounds and the promotion of the associated mechanisms involved in advanced wound healing. Emerging approaches and engineered devices for effective wound care are reported. The discussion will give insight into the mechanisms relevant to all stages of wound healing.

Nanomaterials for Wound Healing and Infection Control

Wound healing has been intensely studied in order to develop an "ideal" technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal agents, in order to prevent infection and promote a proper wound-healing process. Nanotechnology studies submicroscopic particles (maximum diameter of 100 nm), as well as correlated phenomena. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being used in dermatology, due to their beneficial effect on accelerating wound healing, as well as treating and preventing bacterial infections. Other benefits include: ease of use, less frequent dressing changes and a constantly moist wound environment. This review highlights recent findings regarding nanoparticle application in wound management.

The facile fabrication of wound compatible anti-microbial nanoparticles encapsulated Collagenous Chitosan matrices for effective inhibition of poly-microbial infections and wound repairing in burn injury care: Exhaustive in vivo evaluations

Treatment of burn injury is clinically challenging one, therefore several steps and noteworthy approaches have been taken to improve wound mechanisms. Citrus pectin plays a stabilizing agent to synthesis of ZnO nanoparticles (ZnO NPs). The present study is focused on ZnO loaded collagen/chitosan nanofibrous were synthesized by electrospinning method using ZnO NPs. The chemical structure, phase purity and morphological observation were investigated under spectroscopic and mircoscopic techniques and demonstrated their suitable properties as a wound healing material. In addition, that prepared nanoparticles loaded biopolymeric fibrous nanomaterial showed suitable antibacterial activity against S. aureus and E. coli bacterial pathogens and also in vitro studies was confirmed the enhanced proliferation, cell viability and biocompatibility. In vitro evaluations have been exhibited acceptable cell proliferation is observed throughout the ZnO loaded Coll/CS nanofibrous within 3 days, which was comparable to the control material. In vivo wound healing ability was monitored on the rat wound experimental model. From the in vivo observations, revealed that the loaded of ZnO NPs with Coll/CS nanofibrous can effectively quicken wound healing mechanism, expressed in the initial stage healing process. These results suggest that ZnO loaded collagen/chitosan nanofibrous is a potential candidate for wound healing applications with enhanced biological properties.

Nanocarrier-based systems for wound healing

In general, the systems intended for the treatment and recovery of wounds, seek to act as a coating for the damaged area, maintaining an adequate level of humidity, reducing pain, and preventing the invasion and proliferation of microorganisms. Although many of the systems that are currently on the market meet the purposes mentioned above, with the arrival of nanotechnology, it has sought to improve the performance of these coatings. The variety of nano-systems that have been proposed is very extensive, including the use of very different materials (natural or synthetic) ranging from polymers or lipids to systems derived from microorganisms. With the objective of improving the performance of the systems, seeking to combat several of the problems that arise in a wound, especially when it is chronic, these materials have been combined, giving rise to nanocomposites or scaffolds. In recent years, the interest in the development of systems for the treatment of wounds is notable, which is reflected in the increase in publications related to the subject. Therefore, this document presents generalities of systems involving nanocarriers, mentioning some examples of representative systems of each case.

Promising Recent Strategies with Potential Clinical Translational Value to Combat Antibacterial Resistant Surge

Multiple drug resistance (MDR) for the treatment of bacterial infection has been a significant challenge since the beginning of the 21st century. Many of the small molecule-based antibiotic treatments have failed on numerous occasions due to a surge in MDR, which has claimed millions of lives worldwide. Small particles (SPs) consisting of metal, polymer or carbon nanoparticles (NPs) of different sizes, shapes and forms have shown considerable antibacterial effect over the past two decades. Unlike the classical small-molecule antibiotics, the small particles are less exposed so far to the bacteria to trigger a resistance mechanism, and hence have higher chances of fighting the challenge of the MDR process. Until recently, there has been limited progress of clinical treatments using NPs, despite ample reports of in vitro antibacterial efficacy. In this review, we discuss some recent and unconventional strategies that have explored the antibacterial efficacy of these small particles, alone and in combination with classical small molecules in vivo, and demonstrate possibilities that are favorable for clinical translations in near future.