Chitosan-based copper nanocomposite accelerates healing in excision wound model in rats

Advances of biomacromolecule-based antibacterial hydrogels and their performance evaluation for wound healing: A review

Biomacromolecule hydrogels possess excellent mechanical properties and biocompatibility, but their inability to combat bacteria restricts their application in the biomedical field. With the increasing requirements and demands for hydrogel dressings, wound dressings with antibacterial properties of biomacromolecule hydrogels reinforced by adding antibacterial agents have attracted much attention, and related reviews are emerging. In this paper, the advances of biomacromolecule antibacterial hydrogels (including chitosan, sodium alginate, Hyaluronic acid, cellulose and gelatin) were first overviewed, and the antibacterial agents incorporated into hydrogels were classified (including metals and their derivatives, carbon-based materials, and native compounds). A series of performance evaluations of antibacterial hydrogels in the process of promoting wound healing were then reviewed, including basic properties (mechanical, rheological, injectable and self-healing, etc.), in vitro experiments (hemostasis, antibacterial, anti-inflammatory, anti-oxidation, biocompatibility) and in vivo experiments (in vivo model, histomorphology analysis, cytokines). Finally, the future development of biomacromolecule-based antibacterial hydrogels for wound healing is prospected. This work can provide a useful reference for researchers to prepare practical new wound hydrogel dressings.

Design and decoration of copper nanoparticles into lignosulfonate-starch bionanocomposite: Characterization and evaluation of its therapeutic properties on burn wound

In this report, eco-friendly synthesis for the production of copper nanoparticles by employing the sodium lignosulfonate (NaLS) mixed starch composite (NaLS-Starch/Cu NPs). NaLS-Starch mixed hydrogel has notable reducing and stabilizing potential for preparation of Cu nanoparticles. Characterization of NaLS-Starch/Cu NPs bionanocomposite was subjected to analysis of spectroscopic and microscopic techniques, including FE-SEM, TEM, EDS-elemental mapping, particle size distribution, XRD and ICP. TEM images displayed the spherical structured NaLS-Starch/Cu NPs, averaging 5-10 nm size. NaLS-Starch/Cu NPs were applied to cure the induced burn wounds in 60 Wistar rats. A group was considered as control group. The animals were treated with basal, tetracycline 3 % and NaLS-Starch/Cu NPs 3 % for 30 days and the treatment efficacy was determined according to the burn wound area reduction and molecular and histological characteristics. Taken together, these results support therapeutic use of NaLS-Starch/Cu NPs as potent ointment that may be proposed for burn wound healing. NaLS-Starch/Cu NPs ointment increased the levels of platelet-derived growth factors (PDGF) and fibroblast growth factor (bFGF). The mean wound surface, in all groups treated by NaLS-Starch/Cu NPs was larger than control group.

Advancements in breast cancer therapy: The promise of copper nanoparticles

BACKGROUND

Breast cancer (BC) is the most prevalent cancer among women worldwide and poses significant treatment challenges. Traditional therapies often lead to adverse side effects and resistance, necessitating innovative approaches for effective management.

OBJECTIVE

This review aims to explore the potential of copper nanoparticles (CuNPs) in enhancing breast cancer therapy through targeted drug delivery, improved imaging, and their antiangiogenic properties.

METHODS

The review synthesizes existing literature on the efficacy of CuNPs in breast cancer treatment, addressing common challenges in nanotechnology, such as nanoparticle toxicity, scalability, and regulatory hurdles. It proposes a novel hybrid method that combines CuNPs with existing therapeutic modalities to optimize treatment outcomes.

RESULTS

CuNPs demonstrate the ability to selectively target cancer cells while sparing healthy tissues, leading to improved therapeutic efficacy. Their unique physicochemical properties facilitate efficient biodistribution and enhanced imaging capabilities. Additionally, CuNPs exhibit antiangiogenic activity, which can inhibit tumor growth by preventing the formation of new blood vessels.

CONCLUSION

The findings suggest that CuNPs represent a promising avenue for advancing breast cancer treatment. By addressing the limitations of current therapies and proposing innovative solutions, this review contributes valuable insights into the future of nanotechnology in oncology.

Multibiofunctional Self-healing Adhesive Injectable Nanocomposite Polysaccharide Hydrogel

Injectable hydrogels with good antimicrobial and antioxidant properties, self-healing characteristics, suitable mechanical properties, and therapeutic effects have great practical significance for developing treatments for pressing healthcare challenges. Herein, we have designed a novel, self-healing injectable hydrogel composite incorporating cross-linked biofunctional nanomaterials by mixing alginate aldehyde (Ox-Alg), quaternized chitosan (QCS), adipic acid dihydrazide (ADH), and copper oxide nanosheets surface functionalized with folic acid as the bioligand (F-CuO). Gelation was achieved under physiological conditions via the dynamic Schiff base cross-linking mechanism. The developed nanocomposite injectable hydrogel demonstrated the fast self-healing ability essential to bear deformation and outstanding antibacterial properties along with ROS scavenging ability. Furthermore, the optimized formulation of our F-CuO-embedded injectable hydrogel exhibited excellent cytocompatibility, blood compatibility, and in vitro wound healing performance. Taken together, the F-CuO nanosheet cross-linked injectable hydrogel composite presented herein offers a promising candidate biomaterial with multifunctional properties to develop solutions for addressing clinical challenges.

Nanoparticle-Based Strategies for Managing Biofilm Infections in Wounds: A Comprehensive Review

Chronic wounds containing opportunistic bacterial pathogens are a growing problem, as they are the primary cause of morbidity and mortality in developing and developed nations. Bacteria can adhere to almost every surface, forming architecturally complex communities called biofilms that are tolerant to an individual's immune response and traditional treatments. Wound dressings are a primary source and potential treatment avenue for biofilm infections, and research has recently focused on using nanoparticles with antimicrobial activity for infection control. This Review categorizes nanoparticle-based approaches into four main types, each leveraging unique mechanisms against biofilms. Metallic nanoparticles, such as silver and copper, show promising data due to their ability to disrupt bacterial cell membranes and induce oxidative stress, although their effectiveness can vary based on particle size and composition. Phototherapy-based nanoparticles, utilizing either photodynamic or photothermal therapy, offer targeted microbial destruction by generating reactive oxygen species or localized heat, respectively. However, their efficacy depends on the presence of light and oxygen, potentially limiting their use in deeper or more shielded biofilms. Nanoparticles designed to disrupt extracellular polymeric substances directly target the biofilm structure, enhancing the penetration and efficacy of antimicrobial agents. Lastly, nanoparticles that induce biofilm dispersion represent a novel strategy, aiming to weaken the biofilm's defense and restore susceptibility to antimicrobials. While each method has its advantages, the selection of an appropriate nanoparticle-based treatment depends on the specific requirements of the wound environment and the type of biofilm involved. The integration of these nanoparticles into wound dressings not only promises enhanced treatment outcomes but also offers a reduction in the overall use of antibiotics, aligning with the urgent need for innovative solutions in the fight against antibiotic-tolerant infections. The overarching objective of employing these diverse nanoparticle strategies is to replace antibiotics or substantially reduce their required dosages, providing promising avenues for biofilm infection management.

Multi-Faceted Antimicrobial Efficacy of a Quinoline-Derived Bidentate Copper(II) Ligand Complex and Its Hydrogel Encapsulated Formulation in Methicillin-Resistant Staphylococcus aureus Inhibition and Wound Management

The emergence of antimicrobial resistance, exemplified by methicillin-resistant Staphylococcus aureus (MRSA), poses a grave threat to public health globally. Over time, MRSA has evolved resistance to multiple antibiotics, challenging conventional treatment strategies. The relentless adaptability of MRSA underscores the urgent need for innovative and targeted antimicrobial approaches to combat this resilient pathogen. Ancient knowledge and practices, along with scientific evidence, have established that metallic copper, and its organic coordination complexes can act as potential antibacterial substances. In search of a smart and effective antimicrobial against MRSA, we designed, synthesized, and characterized a bidentate copper(II) ligand complex (SG-Cu) utilizing a comprehensive array of analytical techniques, including ESI-MS, elemental analysis, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and others. Antibacterial efficacy and mechanism of action of the complex were assessed through bacterial growth analyses, bacterial membrane perturbation assays, ROS elicitation assays, and field emission scanning electron microscopy. SG-Cu was found to maintain robust biocompatibility against the mammalian cell lines HEK-293, WI-38, and NIH/3T3. Remarkably, SG-Cu demonstrated significant biofilm disruptive tendency evidenced by the retardation of sliding motility, reduction in slime production, reduction in biofilm viability, and enhanced biofilm eradication, both in vitro and in urinary catheters. In vivo studies on murine excisional wounds, with SG-Cu impregnated in a palmitic acid conjugated NAVSIQ hexapeptide (PA-NV) hydrogel, revealed the sustained release of SG-Cu from the gel matrix, facilitating accelerated wound healing and effective wound disinfection. This multifaceted investigation highlights the potential of SG-Cu as a versatile option for combating MRSA infections and promoting wound healing, solidifying its claim to be developed into a viable therapeutic.

Enhancing Diabetic Wound Healing Through Improved Angiogenesis: The Role of Emulsion-Based Core-Shell Micro/Nanofibrous Scaffold with Sustained CuO Nanoparticle Delivery

Attempts are made to design a system for sustaining the delivery of copper ions into diabetic wounds and induce angiogenesis with minimal dose-dependent cytotoxicity. Here, a dual drug-delivery micro/nanofibrous core-shell system is engineered using polycaprolactone/sodium sulfated alginate-polyvinyl alcohol (PCL/SSA-PVA), as core/shell parts, by emulsion electrospinning technique to optimize sustained delivery of copper oxide nanoparticles (CuO NP). Herein, different concentrations of CuO NP (0.2, 0.4, 0.8, and 1.6%w/w) are loaded into the core part of the core-shell system. The morphological, biomechanical, and biocompatibility properties of the scaffolds are fully determined in vitro and in vivo. The 0.8%w/w CuO NP scaffold reveals the highest level of tube formation in HUVEC cells and also upregulates the pro-angiogenesis genes (VEGFA and bFGF) expression with no cytotoxicity effects. The presence of SSA and its interaction with CuO NP, and also core-shell structure sustain the release of the nanoparticles and provide a non-toxic microenvironment for cell adhesion and tube formation, with no sign of adverse immune response in vivo. The optimized scaffold significantly accelerates diabetic wound healing in a rat model. This study strongly suggests the 0.8%w/w CuO NP-loaded PCL/SSA-PVA as an excellent diabetic wound dressing with significantly improved angiogenesis and wound healing.

A novel bola-molecular self-assembling hydrogel for enhancing diabetic wound healing

HYPOTHESIS

Chronic wounds, particularly those caused by diabetes, pose a significant challenge for clinical treatment due to their prolonged healing process and associated complications, which can lead to increased morbidity. A biocompatible hydrogel with strong antibacterial properties and the ability to promote angiogenesis can be directly absorbed in the wound site for healing.

EXPERIMENTS

A series of self-healing, antibacterial bolaamphiphilic supramolecular self-assembling hydrogels (HLQMes/Cu) were developed based on metal-ligand coordination between various concentrations of Cu2+ solution and the head group of l-histidine methyl ester in HLQMes. This is the first report on the application of bola-molecular supramolecular hydrogels for the treatment of chronic wounds.

FINDINGS

The bola-molecular hydrogels reduced the toxicity of copper ions by coordination, and the HLQMes/Cu hydrogel, with 1.3 mg/mL Cu2+ (HLQMes/Cu1.3), demonstrated good biocompatibility and antibacterial properties and effectively enhanced wound healing in a diabetic wound model with full-thickness injuries. Immunohistochemical analysis revealed that the HLQMes/Cu1.3 hydrogel enhanced epithelial formation and collagen deposition in wounds. Immunofluorescence studies confirmed that the HLQMes/Cu1.3 hydrogel attenuated the expression of proinflammatory factor (IL-6) and promoted angiogenesis by upregulating α-SMA and CD31. These findings demonstrate the potential of this bolaamphiphilic supramolecular self-assembling hydrogel as a promising candidate for diabetic wound treatment.

Chitosan nanofibers encapsulating copper oxide nanoparticles: A new approach towards multifunctional ecological membranes with high antimicrobial and antioxidant efficiency

This paper focuses on the preparation of chitosan-based nanofibers embedding copper oxide nanoparticles to create multifunctional materials that meet the demands of contemporary applications. To this end, a mixture of chitosan, quaternized chitosan and poly (ethylene glycol) was used as polymeric matrix, considering their own contribution to the final material's properties and their ability to stabilize the copper oxide nanoparticles. An exhaustive investigation of the nanofibers was done in order to assess their composition and morphology (FTIR, 1H NMR, WXRD, TGA, SEM, TEM, POM, UV-vis) and to study their mechanical, antimicrobial and antioxidant properties, air and water permeability and ability for air filtration. It was shown that the copper oxide nanoparticles were anchored into the polymeric matrix via strong hydrogen bonding and electrostatic interactions, which induced the improvement of the mechanical properties and antioxidant activity. The copper oxide nanoparticles favored the thinning of the fibers during electrospinning process and improved the antibacterial activity and dust filtration capacity. Besides, the fibers displayed air permeability and vapor water transmission rate similar to synthetic nanofibers, while being biodegradable. All these performances recommend the new materials for developing antibacterial eco-materials with good breathability to be used as hygienic textiles, masks, or air filters.

Pharmaceutical applications of chitosan in skin regeneration: A review

Skin regeneration is the process that restores damaged tissues. When the body experiences trauma or surgical incisions, the skin and tissues on the wound surface become damaged. The body repairs this damage through complex physiological processes to restore the original structural and functional states of the affected tissues. Chitosan, a degradable natural bioactive polysaccharide, has attracted widespread attention partly owing to its excellent biocompatibility and antimicrobial properties; additionally, a modified form of this compound has been shown to promote skin regeneration. This review evaluates the recent research progress in the application of chitosan to promote skin regeneration. First, we discuss the basic principles of the extraction and preparation processes of chitosan from its source. Subsequently, we describe the functional properties of chitosan and the optimization of these properties through modification. We then focus on the existing chitosan-based biomaterials developed for clinical applications and their corresponding effects on skin regeneration, particularly in cases of diabetic and burn wounds. Finally, we explore the challenges and prospects associated with the use of chitosan in skin regeneration. Overall, this review provides a reference for related research and contributes to the further development of chitosan-based products in cutaneous skin regeneration.

Chitosan-Stabilized CuO Nanostructure-Functionalized UV-Crosslinked PVA/Chitosan Electrospun Membrane as Enhanced Wound Dressing

Electrospun nanofibrous membranes are of great interest for tissue engineering, active material delivery, and wound dressing. These nanofibers possess unique three-dimensional (3D) interconnected porous structures that result in a higher surface-area-to-volume ratio and porosity. This study was carried out to prepare nanofibrous membranes by electrospinning a blend of PVA/chitosan polymeric solution functionalized with different ratios of copper oxide. Chitosan-stabilized CuO nanoparticles (CH-CuO NPs) were biosynthesized successfully utilizing chitosan as the capping and reducing agent. XRD analysis confirmed the monoclinic structure of CH-CuO NPs. In addition, the electrospun nanofibrous membranes were UV-crosslinked for a definite time. The membranes containing CH-CuO NPs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectrophotometry, and dynamic light scattering (DLS). SEM results showed the nanosize of the fiber diameter in the range of 147-207 nm. The FTIR spectroscopy results indicated the successful incorporation of CH-CuO NPs into the PVA/chitosan nanofibrous membranes. DSC analysis proved the enhanced thermal stability of the nanofibrous membranes due to UV-crosslinking. Swelling and degradation tests were carried out to ensure membrane stability. Greater antimicrobial activity was observed in the nanoparticle-loaded membrane. An in vitro release study of Cu2+ ions from the membrane was carried out for 24 h. The cytotoxicity of CH-CuO NP-incorporated membranes was investigated to estimate the safe dose of nanoparticles. An in vivo test using the CH-CuO NP-loaded PVA/chitosan membrane was conducted on a mice model, in which wound healing occurred in approximately 12 days. These results confirmed that the biocompatible, nontoxic nanofibrous membranes are ideal for wound-dressing applications.

Antibacterial effects of quercetagetin are significantly enhanced upon conjugation with chitosan engineered copper oxide nanoparticles

The development of antibiotic alternatives that entail distinctive chemistry and modes of action is necessary due to the threat posed by drug resistance. Nanotechnology has gained increasing attention in recent years, as a vehicle to enhance the efficacy of existing antimicrobials. In this study, Chitosan copper oxide nanoparticles (CHI-CuO) were synthesized and were further loaded with Quercetagetin (QTG) to achieve the desired (CHI-CuO-QTG). Size distribution, zeta potential and morphological analysis were accomplished. Next, the developed CHI-CuO-QTG was assessed for synergistic antibacterial properties, as well as cytotoxic attributes. Bactericidal assays revealed that CHI-CuO conjugation showed remarkable effects and enhanced QTG effects against a range of Gram + ve and Gram - ve bacteria. The MIC50 of QTG against S. pyogenes was 107 µg/mL while CHI-CuO-QTG reduced it to 9 µg/mL. Similar results were observed when tested against S. pneumoniae. Likewise, the MIC50 of QTG against S. enterica was 38 µg/mL while CHI-CuO-QTG reduced it to 7 µg/mL. For E. coli K1, the MIC50 of QTG was 42 µg/mL while with CHI-CuO-QTG it was 23 µg/mL. Finally, the MIC50 of QTG against S. marcescens was 98 µg/mL while CHI-CuO-QTG reduced it to 10 µg/mL. Notably, the CHI-CuO-QTG nano-formulation showed limited damage when tested against human cells using lactate dehydrogenase release assays. Importantly, bacterial-mediated human cell damage was reduced by prior treatment of bacteria using drug nano-formulations. These findings are remarkable and clearly demonstrate that drug-nanoparticle formulations using nanotechnology is an important avenue in developing potential therapeutic interventions against microbial infections.

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.

Supramolecular hydrogels for wound repair and hemostasis

The unique network characteristics and stimuli responsiveness of supramolecular hydrogels have rendered them highly advantageous in the field of wound dressings, showcasing unprecedented potential. However, there are few reports on a comprehensive review of supramolecular hydrogel dressings for wound repair and hemostasis. This review first introduces the major cross-linking methods for supramolecular hydrogels, which includes hydrogen bonding, electrostatic interactions, hydrophobic interactions, host-guest interactions, metal ligand coordination and some other interactions. Then, we review the advanced materials reported in recent years and then summarize the basic principles of each cross-linking method. Next, we classify the network structures of supramolecular hydrogels before outlining their forming process and propose their potential future directions. Furthermore, we also discuss the raw materials, structural design principles, and material characteristics used to achieve the advanced functions of supramolecular hydrogels, such as antibacterial function, tissue adhesion, substance delivery, anti-inflammatory and antioxidant functions, cell behavior regulation, angiogenesis promotion, hemostasis and other innovative functions in recent years. Finally, the existing problems as well as future development directions of the cross-linking strategy, network design, and functions in wound repair and hemostasis of supramolecular hydrogels are discussed. This review is proposed to stimulate further exploration of supramolecular hydrogels on wound repair and hemostasis by researchers in the future.

Electrospun Nanofiber Scaffolds Loaded with Metal-Based Nanoparticles for Wound Healing

Failures of wound healing have been a focus of research worldwide. With the continuous development of materials science, electrospun nanofiber scaffolds loaded with metal-based nanoparticles provide new ideas and methods for research into new tissue engineering materials due to their excellent antibacterial, anti-inflammatory, and wound healing abilities. In this review, the stages of extracellular matrix and wound healing, electrospun nanofiber scaffolds, metal-based nanoparticles, and metal-based nanoparticles supported by electrospun nanofiber scaffolds are reviewed, and their characteristics and applications are introduced. We discuss in detail the current research on wound healing of metal-based nanoparticles and electrospun nanofiber scaffolds loaded with metal-based nanoparticles, and we highlight the potential mechanisms and promising applications of these scaffolds for promoting wound healing.

Characterization and Bio-Evaluation of the Synergistic Effect of Simvastatin and Folic Acid as Wound Dressings on the Healing Process

Wound healing is a significant healthcare problem that decreases the patient's quality of life. Hence, several agents and approaches have been widely used to help accelerate wound healing. The challenge is to search for a topical delivery system that could supply long-acting effects, accurate doses, and rapid healing activity. Topical forms of simvastatin (SMV) are beneficial in wound care. This study aimed to develop a novel topical chitosan-based platform of SMV with folic acid (FA) for wound healing. Moreover, the synergistic effect of combinations was determined in an excisional wound model in rats. The prepared SMV-FA-loaded films (SMV-FAPFs) were examined for their physicochemical characterizations and morphology. Box-Behnken Design and response surface methodology were used to evaluate the tensile strength and release characteristics of the prepared SMV-FAPFs. Additionally, Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), X-ray diffraction pattern (XRD), and animal studies were also investigated. The developed SMV-FAPFs showed a contraction of up to 80% decrease in the wound size after ten days. The results of the quantitative real-time polymerase chain reaction (RT-PCR) analysis demonstrated a significant upregulation of dermal collagen type I (CoTI) expression and downregulation of the inflammatory JAK3 expression in wounds treated with SMV-FAPFs when compared to control samples and individual drug treatments. In summary, it can be concluded that the utilization of SMV-FAPFs holds great potential for facilitating efficient and expeditious wound healing, hence presenting a feasible substitute for conventional topical administration methods.

Multifunctional nanozyme-reinforced copper-coordination polymer nanoparticles for drug-resistance bacteria extinction and diabetic wound healing

BACKGROUND

Drug-resistant bacterial infections in chronic wounds are a persistent issue, as they are resistant to antibiotics and can cause excessive inflammation due to generation of reactive oxygen species (ROS). An effective solution would be to not only combat bacterial infections but also scavenge ROS to relieve inflammation at the wound site. Scaffolds with antioxidant properties are attractive for their ability to scavenge ROS, and there is medical demand in developing antioxidant enzyme-mimicking nanomaterials for wound healing.

METHODS

In this study, we fabricated copper-coordination polymer nanoparticles (Cu-CPNs) through a self-assembly process. Furthermore, ε-polylysine (EPL), an antibacterial and cationic polymer, was integrated into the Cu-CPNs structure through a simple one-pot self-assembly process without sacrificing the glutathione peroxidase (GPx) and superoxide dismutase (SOD)-mimicking activity of Cu-CPNs.

RESULTS

The resulting Cu-CPNs exhibit excellent antioxidant propertiesin mimicking the activity of glutathione peroxidase and superoxide dismutase and allowing them to effectively scavenge harmful ROS produced in wound sites. The in vitro experiments showed that the resulting Cu-CPNs@EPL complex have superior antioxidant properties and antibacterial effects. Bacterial metabolic analysis revealed that the complex mainly affects the cell membrane integrity and nucleic acid synthesis that leads to bacterial death.

CONCLUSIONS

The Cu-CPNs@EPL complex has impressive antioxidant properties and antibacterial effects, making it a promising solution for treating drug-resistant bacterial infections in chronic wounds. The complex's ability to neutralize multiple ROS and reduce ROS-induced inflammation can help relieve inflammation at the wound site. Schematic illustration of the ROS scavenging and bacteriostatic function induced by Cu-CPNs@EPL nanozyme in the treatment of MRSA-infected wounds.

Transplantation of Bone Marrow Cells Preactivated With Sodium Nitroprusside Improves Acute Wound Healing in Rabbits

The development of wound healing impairment mainly represents challenging clinical problems. The less and high concentrations of nitric oxide can influence angiogenesis, remodeling, and proliferation of skin cells. Delayed acute wounds generally have failed to progress via the normal stages of healing. Such wounds usually enter a state of pathological inflammation due to a postponed, incomplete, and uncoordinated healing process. This study aimed to investigate the effect of normal bone marrow cells (BMCs) and preconditioning of BMCs with minimum concentrations of sodium nitroprusside (NaNP) solution for acute wound healing. For acute wound healing, full-thickness dorsal wounds were created on rabbits. The acute wound of rabbits was treated with BMCs and preactivated BMCs with NaNP. Histological results showed that BMCs preactivated with NaNP could improve collagen deposition, enhanced reepithelization, and decreased inflammatory infiltration. Overall, BMCs treated with NaNP can help to improve acute wound healing in rabbits. The result strongly confirmed the beneficial effect in augmenting the wound healing process. The combination of BMCs with NaNP was safe and convenient for acute wound healing.

Functional molecule-mediated assembled copper nanozymes for diabetic wound healing

BACKGROUND

The complex hyperglycemic, hypoxic, and reactive oxygen species microenvironment of diabetic wound leads to vascular defects and bacterial growth and current treatment options are relatively limited by their poor efficacy.

RESULTS

Herein, a functional molecule-mediated copper ions co-assembled strategy was constructed for collaborative treatment of diabetic wounds. Firstly, a functional small molecule 2,5-dimercaptoterephthalic acid (DCA) which has symmetrical carboxyl and sulfhydryl structure, was selected for the first time to assisted co-assembly of copper ions to produce multifunctional nanozymes (Cu-DCA NZs). Secondly, the Cu-DCA NZs have excellent multicatalytic activity, and photothermal response under 808 nm irradiation. In vitro and in vivo experiments showed that it not only could efficiently inhibit bacterial growth though photothermal therapy, but also could catalyze the conversion of intracellular hydrogen peroxide to oxygen which relieves wound hypoxia and improving inflammatory accumulation. More importantly, the slow release of copper ions could accelerate cellular proliferation, migration and angiogenesis, synergistically promote the healing of diabetic wound furtherly.

CONCLUSIONS

The above results indicate that this multifunctional nanozymes Cu-DCA NZs may be a potential nanotherapeutic strategy for diabetic wound healing.

Applications of drug delivery systems, organic, and inorganic nanomaterials in wound healing

The skin is known to be the largest organ in the human body, while also being exposed to environmental elements. This indicates that skin is highly susceptible to physical infliction, as well as damage resulting from medical conditions such as obesity and diabetes. The wound management costs in hospitals and clinics are expected to rise globally over the coming years, which provides pressure for more wound healing aids readily available in the market. Recently, nanomaterials have been gaining traction for their potential applications in various fields, including wound healing. Here, we discuss various inorganic nanoparticles such as silver, titanium dioxide, copper oxide, cerium oxide, MXenes, PLGA, PEG, and silica nanoparticles with their respective roles in improving wound healing progression. In addition, organic nanomaterials for wound healing such as collagen, chitosan, curcumin, dendrimers, graphene and its derivative graphene oxide were also further discussed. Various forms of nanoparticle drug delivery systems like nanohydrogels, nanoliposomes, nanofilms, and nanoemulsions were discussed in their function to deliver therapeutic agents to wound sites in a controlled manner.

Microenvironment responsive nanocomposite hydrogel with NIR photothermal therapy, vascularization and anti-inflammation for diabetic infected wound healing

Bacterial infection, excessive inflammation and damaging blood vessels network are the major factors to delay the healing of diabetic ulcer. At present, most of wound repair materials are passive and can't response to the wound microenvironment, resulting in a low utilization of bioactive substances and hence a poor therapeutic effect. Therefore, it's essential to design an intelligent wound dressing responsive to the wound microenvironment to achieve the release of drugs on-demand on the basis of multifunctionality. In this work, metformin-laden CuPDA NPs composite hydrogel (Met@ CuPDA NPs/HG) was fabricated by dynamic phenylborate bonding of gelatin modified by dopamine (Gel-DA), Cu-loaded polydopamine nanoparticles (CuPDA NPs) with hyaluronic acid modified by phenyl boronate acid (HA-PBA), which possessed good injectability, self-healing, adhesive and DPPH scavenging performance. The slow release of metformin was achieved by the interaction with CuPDA NPs, boric groups (B-N coordination) and the constraint of hydrogel network. Metformin had a pH and glucose responsive release behavior to treat different wound microenvironment intelligently. Moreover, CuPDA NPs endowed the hydrogel excellent photothermal responsiveness to kill bacteria of >95% within 10 min and also the slow release of Cu²⁺ to protect wound from infection for a long time. Met@ CuPDA NPs/HG also recruited cells to a certain direction and promoted vascularization by releasing Cu²⁺. More importantly, Met@CuPDA NPs/HG effectively decreased the inflammation by eliminating ROS and inhibiting the activation of NF-κB pathway. Animal experiments demonstrated that Met@CuPDA NPs/HG significantly promoted wound healing of diabetic SD rats by killing bacteria, inhibiting inflammation, improving angiogenesis and accelerating the deposition of ECM and collagen. Therefore, Met@CuPDA NPs/HG had a great application potential for diabetic wound healing.

Adhesive Composite Microspheres with Dual Antibacterial Strategies for Infected Wound Healing

Skin damage and infection pose a severe challenge to human health. Construction of a novel versatile dressing with good anti-infection and healing-promoting abilities is greatly expected. In this paper, nature-source-based composite microspheres with dual antibacterial mechanisms and bioadhesive features by microfluidics electrospray for infected wound healing is developed. The microspheres enable sustained release of copper ions, which not only show long-term antibacterial properties, but also play important role in wound-healing-related angiogenesis. Additionally, the microspheres are coated with polydopamine via self-polymerization, which renders the microspheres adhesive to the wound surface, and further enhance the antibacterial ability through photothermal energy conversion. Based on the dual antibacterial strategies provided by copper ions and polydopamine as well as the bioadhesive property, the composite microspheres exhibit excellent anti-infection and wound healing performances in a rat wound model. These results, along with the nature-source-based composition and biocompatibility, indicate the great potential of the microspheres in clinical wound repair.

Pectin Nanoparticle-Loaded Soft Coral Nephthea sp. Extract as In Situ Gel Enhances Chronic Wound Healing: In Vitro, In Vivo, and In Silico Studies

This study shed light for the first time on the in vivo diabetic wound healing potential activity of natural marine soft coral polymeric nanoparticle in situ gel using an excision wound model. A Nephthea sp. methanol-methylene chloride extract loaded with pectin nanoparticles (LPNs) was created. For the preparation of in situ gel, ion-gelation techniques, the entrapment efficiency, the particle size, the polydispersity index, the zeta potential, the in-vitro drug release, and a transmission electron microscope were used and the best formula was selected. Using (UPLC-Q/TOF-MS), 27 secondary metabolites responsible for extract biological activity were identified. Isolation and identification of arachidic acid, oleic acid, nervonic acid, and bis-(2-ethylhexyl)-phthalate (DEHP) of Nephthea sp. was firstly reported here using NMR and mass spectral analyses. Moreover, LPN in situ gel has the best effects on regulating the proinflammatory cytokines (NF-κB, TNF-α, IL-6, and IL-1β) that were detected on days 7 and 15. The results were confirmed with an in vitro enzymatic inhibitory effect of the extract against glycogen synthase kinase (GSK-3) and matrix metalloproteinase-1 (MMP-1), with IC₅₀ values of 0.178 ± 0.009 and 0.258 ± 0.011 µg/mL, respectively. The molecular docking study showed a free binding energy of -9.6 kcal/mol for chabrolosteroid E, with the highest binding affinity for the enzyme (GSK-3), while isogosterone B had -7.8 kcal/mol for the enzyme (MMP-1). A pharmacokinetics study for chabrolohydroxybenzoquinone F and isogosterone B was performed, and it predicted the mode of action of wound healing activity.

Zinc-based subcuticular absorbable staples: An in vivo and in vitro study

A zinc-nutrient element alloy (Zn-1.0Cu-0.5Ca) was developed into subcuticular absorbable staples (SAS) as a robust alternative to the commercially available poly(l-lactide-co-glycolide) (PLGA) SAS for the first time. The fixation properties of the Zn SAS were measured via pull-out tests and in-situ lap-shear pull-out test comparatively against the PLGA SAS. The Zn SAS exhibited fixation force of 18.9±0.2 N, which was over three times higher than that of PLGA SAS (5.5±0.1 N). The Zn SAS was used to close incision wounds in a SD rat model for biodegradability and biocompatibility characterisation at 1, 4 and 12 weeks. The Zn SAS showed uniform degradation behaviour after in vivo implantation at the average rate of 198±54, 112±28, and 70±24 μm/y after 1, 4, and 12 weeks, which reduced the fixation force to 16.8±1.1 N, 15.4±0.9 N, 12.7±0.7 N, respectively. These findings showed the potential of the Zn SAS for the closure of heavy loading and slowing healing tissues. The Zn SAS enabled successful closure and healing of the incision wound, similar to the PLGA staples. However, the slow long-term degradation rate of the Zn SAS may lead to unnecessary implant retention. In addition, the alloy SAS resulted in higher local foreign body responses due to their stiffness. Reducing the implant cross-section profile and applying low stiffness and a corrosion-accelerating coating are suggested as possible approaches to reduce post-service implant retention and improve the biocompatibility of the Zn SAS. STATEMENT OF SIGNIFICANCE: This work reports the fabrication of the first metallic subcuticular absorbable staples (SAS) made from Zn-Cu-Ca alloy for skin wound closure applications. The Zn-based SAS were characterised in vitro and in vivo (SD rat model) for biodegradability, fixation properties, biocompatibility and inflammatory responses, which were compared against the commercially available PLGA-based SAS. The Zn-based SAS provided a secure attachment of the full-thickness wounds on SD rats and allowed successful healing during the 12-week service period. In addition, the in vitro results showed that the Zn-based SAS provided more than three times higher fixation strength than the commercial PLGA, indicating the potential of the Zn-based SAS for load-bearing wound closure application.

Chronic Wound Healing Models

In this paper, we review and analyze the commonly available wound healing models reported in the literature and discuss their advantages and issues, considering their relevance and translational potential to humans. Our analysis includes different in vitro and in silico as well as in vivo models and experimental techniques. We further explore the new technologies in the study of wound healing to provide an all encompassing review of the most efficient ways to proceed with wound healing experiments. We revealed that there is not one model of wound healing that is superior and can give translatable results to human research. Rather, there are many different models that have specific uses for studying certain processes or stages of wound healing. Our analysis suggests that when performing an experiment to assess stages of wound healing or different therapies to enhance healing, one must consider not only the species that will be used but also the type of model and how this can best replicate the physiology or pathophysiology in humans.

Evolution of nanostructured skin patches towards multifunctional wearable platforms for biomedical applications

Recent advances in the field of skin patches have promoted the development of wearable and implantable bioelectronics for long-term, continuous healthcare management and targeted therapy. However, the design of electronic skin (e-skin) patches with stretchable components is still challenging and requires an in-depth understanding of the skin-attachable substrate layer, functional biomaterials and advanced self-powered electronics. In this comprehensive review, we present the evolution of skin patches from functional nanostructured materials to multi-functional and stimuli-responsive patches towards flexible substrates and emerging biomaterials for e-skin patches, including the material selection, structure design and promising applications. Stretchable sensors and self-powered e-skin patches are also discussed, ranging from electrical stimulation for clinical procedures to continuous health monitoring and integrated systems for comprehensive healthcare management. Moreover, an integrated energy harvester with bioelectronics enables the fabrication of self-powered electronic skin patches, which can effectively solve the energy supply and overcome the drawbacks induced by bulky battery-driven devices. However, to realize the full potential offered by these advancements, several challenges must be addressed for next-generation e-skin patches. Finally, future opportunities and positive outlooks are presented on the future directions of bioelectronics. It is believed that innovative material design, structure engineering, and in-depth study of fundamental principles can foster the rapid evolution of electronic skin patches, and eventually enable self-powered close-looped bioelectronic systems to benefit mankind.

Acid-degradable nanocomposite hydrogel and glucose oxidase combination for killing bacterial with photothermal augmented chemodynamic therapy

Bacterial infection often delays diabetic wound healing, and even causes serious life-threatening complications. Herein, we successfully developed a Cu₂O/Pt nanocubes-dopping alginate (ALG)- hyaluronic acid (HA) hydrogel (Cu₂O/Pt hydrogel) by simple assembly of the Cu₂O/Pt nanocubes and the ALG-HA mixture. The Cu₂O/Pt hydrogel combined with the glucose oxidase (GOx) can be used for photothermal- and starving-enhanced chemodynamic therapy (CDT) against Gram-negative and Gram-positive bacteria. The GOx can catalyze the glucose to produce gluconic acid and H₂O₂ for starvation therapy, following which the released Cu₂O/Pt nanocubes react with H₂O₂ in the acidic microenvironment to generate highly cytotoxic hydroxyl radicals (·OH) for CDT. Additionally, the Cu₂O/Pt hydrogel can release copper ions gradually with the decrease of pH induced by gluconic acid, which can increase the protein expression and secretion of vascular endothelial growth factor (VEGF) and promote endothelial cell proliferation, migration and angiogenesis, subsequently promoting diabetic wound healing in rats. Our results suggested that the Cu₂O/Pt hydrogel combined with GOx may be a potential therapeutic approach for treating the infected diabetic wound.

A biotin-stabilized HKUST-1/ADM scaffold for facilitating MSC endothelial differentiation and vascularization in diabetic wound healing

Inadequate angiogenesis in diabetic wound healing has been identified as one of the most difficult issues to treat. Copper ions (Cu²⁺) have been confirmed to stimulate angiogenesis; nevertheless, the rapid rise in non-physiological Cu²⁺ concentrations increases the danger of ion poisoning. For the first time, biotin was used to stabilize a copper-based metal-organic framework (HKUST-1) to change its hydrophobicity and achieve sustained release of Cu²⁺. The inability to offer a suitable area for the dynamic interaction between cells and growth factors still restricts the use of nanomaterials for the regeneration of injured skin in diabetes. Acellular dermal matrix (ADM) scaffolds are collagen fibers with natural spatial tissue that can create a biological "niche" for cell attachment and growth. In this study, biotin-stabilized HKUST-1 (B-HKUST-1) nanoparticles were modified with an ADM to form a novel scaffold (ADM-B-HKUST-1). Notably, Cu²⁺ and mesenchymal stem cells (MSCs) released by the composite scaffold may synergistically promote MSC adhesion, proliferation and endothelial differentiation by upregulating the expression of transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF) and alpha-smooth muscle actin (α-SMA). Overall, the ADM-B-HKUST1 scaffold combines the dual advantages of the sustained release of Cu²⁺ and creating a biological "niche" can provide a potential strategy for enhancing angiogenesis and promoting diabetic wound healing.

Anti-inflammatory and collagenation effects of zinc oxide-based nanocomposites biosynthesised with Mentha longifolia leaf extract

OBJECTIVE

The integration of nanomaterials and herbal medicine has led to the design of new nanocomposites, which are therapeutically more effective. The purpose of this study was to prepare different zinc oxide (ZnO)-based nanoparticles (NPs) via Mentha longifolia extract based on gauze linen fibre and study its effects on wound healing.

METHODS

The textural properties, morphology, thermal stability, purity, spectroscopic and phase structure of nanoparticles were investigated. Subsequently, male Wistar rats were subjected to wounds in six different treatment groups: Group I: control; group II: ZnO/W prepared in water (W); group III: ZnO/M synthesised with Mentha longifolia (M) extract; group IV: ZnO/copper(II) oxide (CuO)/M nanocomposite synthesised with M extract; group IV: treated with ZnO/silver (Ag)/M nanocomposite; group V: treated with ZnO/Ag/M nanocomposite; and finally, group VI: treated with ZnO/CuO/Ag/M nanocomposite. In all groups, the wounds were treated for 21 days with prepared samples. Every seven days, after measuring the decreasing rate of the wound size, tissue samples from each group were taken for histopathological analysis. The prepared tissue sections were assessed by haematoxylin and eosin staining for the formation of the epidermis, dermis and muscular tissue, and Masson's Trichrome staining for the formation of collagen fibres.

RESULTS

The results showed that the ZnO/CuO/Ag/M nanocomposite was a significantly more effective wound healing material in comparison with other samples (p<0.05).

CONCLUSION

In this study, the integration of ZnO/CuO/Ag nanocomposites with secondary metabolites of Mentha longifolia gave rise to a superior combination, which could support different phases of wound healing via the regulation of cytokines and growth factors in the course of healing.

A critical review on nanomaterial based therapeutics for diabetic wound healing

Diabetes mellitus is a chronic endocrine disease that occurs mostly in the state of hyperglycemia (elevated blood glucose level). In the recent times, diabetes is listed under world's utmost critical health issues. Wound treatment procedures are complicated in diabetic individuals all over the world. Diabetic wound care not only involves high-cost, but also the primary cause of hospitalization, which can lead to amputation thereby reducing diabetic patient life expectancy. To lower the risk of amputation, wound healing requires the development of effective treatments. Traditional management systems for Diabetes are frequently chastised due to their high costs, difficulties in maintaining a sustainable supply chain and limited disposal alternatives. The worrisome rise in diabetes prevalence has sparked a surge of interest in the discovery of viable remedies to supplement existing treatments. Nanomaterials wound healing has a lot of potential for treating and preventing wound infections and it has recently gained popularity owing to its ability to transport drugs to the wound area in a regulated fashion, potentially overpowering the limits of traditional approaches. This research assessed several nanosystems, such as nanocarriers and nanotherapeutics, to explore how they can benefit in diabetic wound healing, with a focus on current obstacles and future prospects.

Effect of composite biodegradable biomaterials on wound healing in diabetes

The repair of diabetic wounds has always been a job that doctors could not tackle quickly in plastic surgery. To solve this problem, it has become an important direction to use biocompatible biodegradable biomaterials as scaffolds or dressing loaded with a variety of active substances or cells, to construct a wound repair system integrating materials, cells, and growth factors. In terms of wound healing, composite biodegradable biomaterials show strong biocompatibility and the ability to promote wound healing. This review describes the multifaceted integration of biomaterials with drugs, stem cells, and active agents. In wounds, stem cells and their secreted exosomes regulate immune responses and inflammation. They promote angiogenesis, accelerate skin cell proliferation and re-epithelialization, and regulate collagen remodeling that inhibits scar hyperplasia. In the process of continuous combination with new materials, a series of materials that can be well matched with active ingredients such as cells or drugs are derived for precise delivery and controlled release of drugs. The ultimate goal of material development is clinical transformation. At present, the types of materials for clinical application are still relatively single, and the bottleneck is that the functions of emerging materials have not yet reached a stable and effective degree. The development of biomaterials that can be further translated into clinical practice will become the focus of research.

Curcumin-Polyethylene Glycol Loaded on Chitosan-Gelatin Nanoparticles Enhances Burn Wound Healing in Rat

The aim of the present study was to evaluate effects of curcumin-polyethylene glycol loaded on chitosan-gelatin nanoparticles (C-PEG-CGNPs) on burn wound healing in rat as a model study. Sixty healthy male White Wistar rats were randomized into four experimental groups of 15 animals each: Control group (Control) was treated with normal saline. Carrier group was treated with CGNPs-based ointment (0.05 mg/ml). Silver sulfadiazine group was treated with silver sulfadiazine 1% ointment. Treatment group was treated with C-PEG-CGNPs (0.05 mg/ml). Wound size was measured on 7, 14, and 21 days after surgery. The expression of p53, Bcl-2, caspase-3 were evaluated using reverse transcription-polymerase chain reaction and immunohistochemical staining. Reduction in wound area indicated that there was significant difference between Treatment group and other groups (P &lt; .05). Quantitative histological and morphometric studies, and mean rank of the qualitative studies demonstrated that there was a significant difference between Treatment group and other groups (P &lt; .05). Observations demonstrated C-PEG-CGNPs significantly shortened the inflammatory phase and accelerated the cellular proliferation. Accordingly, the animals in Treatment group revealed significantly (P &lt; .05) higher fibroblast distribution/one mm2 of wound area and rapid reepithelialization. The mRNA levels of Bcl-2, p53, and caspase-3 were remarkably (P &lt; .05) higher in Treatment group compared to control animals. The immunohistochemical analyses confirmed the reverse transcription-polymerase chain reaction findings. C-PEG-CGNPs offered potential advantages in burn wound healing acceleration and improvement.

Bioactive inorganic particles-based biomaterials for skin tissue engineering

The challenge for treatment of severe cutaneous wound poses an urgent clinical need for the development of biomaterials to promote skin regeneration. In the past few decades, introduction of inorganic components into material system has become a promising strategy for improving performances of biomaterials in the process of tissue repair. In this review, we provide a current overview of the development of bioactive inorganic particles-based biomaterials used for skin tissue engineering. We highlight the three stages in the evolution of the bioactive inorganic biomaterials applied to wound management, including single inorganic materials, inorganic/organic composite materials, and inorganic particles-based cell-encapsulated living systems. At every stage, the primary types of bioactive inorganic biomaterials are described, followed by citation of the related representative studies completed in recent years. Then we offer a brief exposition of typical approaches to construct the composite material systems with incorporation of inorganic components for wound healing. Finally, the conclusions and future directions are suggested for the development of novel bioactive inorganic particles-based biomaterials in the field of skin regeneration.

Copper-containing titanium alloys promote angiogenesis in irradiated bone through releasing copper ions and regulating immune microenvironment

Poor vascularization was demonstrated as a factor inhibiting bone regeneration in patients receiving radiotherapy. Various copper-containing materials have been reported to increase angiogenesis, therefore might improve bone formation. In this study, a Ti6Al4V-1.5Cu alloy was prepared using selective laser melting (SLM) technology. The immunomodulatory and pro-angiogenic effects of the Ti6Al4V-1.5Cu alloys were examined. In vitro, Ti6Al4V-1.5Cu stimulated vascular formation by restraining inflammatory factors and provoking angiogenic factors in non-irradiated and irradiated macrophages. In vivo, the angiogenic effects of the Ti6Al4V-1.5Cu alloy were confirmed using an irradiated rat femur defect model. Moreover, we found that the biological effects of the Ti6Al4V-1.5Cu alloy were partially due to the release of copper ions and associated with PI3K-Akt signaling pathway. In conclusion, this study indicated the potential of the Ti6Al4V-1.5Cu alloy to promote angiogenesis by releasing copper ions and inhibiting inflammation in normal and irradiated tissues.

Antibacterial adhesive self-healing hydrogels to promote diabetic wound healing

The development of compressible, stretchable and self-healing hydrogel dressings with good adhesive, antibacterial and angiogenesis properties is needed to promote the regeneration of diabetic wounds in clinical applications. In this work, a series of self-healing, adhesive and antibacterial hydrogels based on gelatin methacrylate (GelMA), adenine acrylate (AA), and CuCl₂ were designed through covalent bonding, coordination complexation of Cu²⁺ and carboxyl groups and hydrogen bonding to promote diabetic wound healing. These hydrogels exhibit efficient self-healing properties, remarkable fatigue resistance, and good adhesive properties due to the hydrogen bond and the metal-ligand coordination provided by the Cu²⁺ and the carboxyl group. The GelMA/AA/Cu1.0 hydrogel (containing 1.0 mg/mL Cu²⁺) with well-balanced biocompatibility and antibacterial properties exhibited efficient hemostatic performance in a mouse liver trauma model and significantly promoted the healing process in a full-thickness skin diabetic wound model. The immunohistochemistry results showed that the GelMA/AA/Cu1.0 hydrogel can promote regular epithelialization and collagen deposition when compared to the Tegaderm^TM Film, GelMA hydrogel, and GelMA/AA/Cu0 hydrogel. The immunofluorescence results confirmed that the GelMA/AA/Cu1.0 hydrogel can reduce the expression of proinflammatory factors and promote angiogenesis. In conclusion, the GelMA/AA/Cu hydrogel is an effective wound dressing to promote the healing process of diabetic skin wounds. STATEMENT OF SIGNIFICANCE: Diabetic wounds exhibit an extremely high risk of bacterial infection and poor angiogenesis in a high-sugar environment, hindering their healing process. Hydrogel wound dressings are a promising wound care material that need to have stable and long-lasting adhesive properties, avoid shedding, provide lasting protection to wounds, antibacterial properties and promote angiogenesis. In this study, a series of self-healing, adhesive, and antibacterial hydrogels based on gelatin methacrylate (GelMA), acrylated adenine (AA), and CuCl₂ were designed and synthesized via free radical polymerization, hydrogen bond, and ionic bond to promote diabetic wound healing. Overall, GelMA/AA/Cu hydrogels are promising materials to promote diabetic wound healing.

A comprehensive study to evaluate the wound healing potential of okra (Abelmoschus esculentus) fruit

ETHNOPHARMACOLOGICAL RELEVANCE

Okra fruit (Abelmoschus esculentus (L.) Moench) has been extensively used for the treatment of skin damage and subcutaneous tissue abscess for many years in Turkish folk medicine.

AIM OF STUDY

In this study, we aimed to investigate the wound healing potential of okra fruit by in vitro and in vivo experimental models in detail. Furthermore, based on the results of experiments, a wound healing formulation was developed and its activity profile was studied.

MATERIALS AND METHODS

For this purpose, the phenolic, flavonoid and proanthocyanidin contents and chemical profile of aqueous and ethanolic extracts prepared from okra fruits cultivated in two different locations of Turkey, i.e. Aegean and Kilis regions, were comparatively determined and the tryptophan levels, which is known to be an influential factor in wound healing, were measured. Antioxidant activity of the okra fruit extracts was determined by DPPH test, ABTS radical scavenger activity, iron-binding capacity, total antioxidant capacity and copper reduction capacity assays. Moreover, antibacterial activity potentials of the aqueous and ethanolic extracts of okra fruits were determined. The protective effect of the extracts against H₂O₂-induced oxidative stress and anti-inflammatory activity were assessed in HDF (human dermal fibroblast) cells and in RAW 264.7 murine macrophages, respectively. The biocompatibility of the gel formulations prepared with the best performing extract were evaluated by human Epiderm™ reconstituted skin irritation test model. Wound-healing activity was investigated in rats by in vivo excision model and, histopathological examination of tissues and gene expression levels of inflammation markers were also determined.

RESULTS

According to our findings, the aqueous and ethanolic extracts of okra fruits were found to possess a rich in phenolic content. Besides, isoquercitrin was found to be a marker component in ethanolic extracts of okra fruits. Both extracts exhibited antioxidant activity with significant protective effect against H₂O₂-induced damage in HDF cells by diminishing the MDA level. Also, the highest dose of ethanolic extracts has displayed a potent anti-inflammatory activity on LPS-induced RAW264.7 cells. Besides, both water and ethanolic extracts were shown to possess antimicrobial activity. On the other hand, the formulations prepared from the extracts were found non-irritant on in vitro Epiderm™-SIT. In vivo excision assay showed that tissue TGF-β and IL-1β levels were significantly decreased by the 5% okra ethanolic gel formulation. The histopathological analysis also demonstrated that collagenisation and granulation tissue maturation were found higher in 5% (w/v) okra ethanolic extract-treated group.

CONCLUSION

5% of okra ethanolic extract might be suggested as a potent wound healing agent based on the antimicrobial, antioxidant and anti-inflammatory tests. The proposed activity was also confirmed by the histopathological findings and gene expression analysis.

Nanomaterials-based drug delivery approaches for wound healing

Abstract:

Wound healing is a complex and dynamic process that requires intricate synchronization between multiple cell types within appropriate extracellular microenvironment. Wound healing process involves four overlapping phases in a precisely regulated manner, consisting of hemostasis, inflammation, proliferation, and maturation. For an effective wound healing all four phases must follow in a sequential pattern within a time frame. Several factors might interfere with one or more of these phases in healing process, thus causing improper or impaired wound healing resulting in non-healing chronic wounds. The complications associated with chronic non-healing wounds, along with the limitations of existing wound therapies, have led to the development and emergence of novel and innovative therapeutic interventions. Nanotechnology presents unique and alternative approaches to accelerate the healing of chronic wounds by the interaction of nanomaterials during different phases of wound healing. This review focuses on recent innovative nanotechnology-based strategies for wound healing and tissue regeneration based on nanomaterials, including nanoparticles, nanocomposites and scaffolds. The efficacy of the intrinsic therapeutic potential of nanomaterials (including silver, gold, zinc oxide, copper, cerium oxide, etc.) and the ability of nanomaterials as carriers (liposomes, hydrogels, polymeric nanomaterials, nanofibers) as therapeutic agents associated with wound-healing applications have also been addressed. The significance of these nanomaterial-based therapeutic interventions for wound healing needs to be highlighted to engage researchers and clinicians towards this new and exciting area of bio-nanoscience. We believe that these recent developments will offer researchers an updated source on the use of nanomaterials as an advanced approach to improve wound healing.

Carbon-Based Nanomaterials: Carbon Nanotubes, Graphene and Fullerenes in Control of Burns Infections and Wound Healing

Burn injuries are extremely debilitating, resulting in high morbidity and mortality rates around the world. The risk of infection escalates in correlation with impairment of skin integrity, creating a barrier to healing and possibly leading to sepsis. With its numerous advantages over traditional treatment methods, nanomaterial-based wound healing has immense capability for treating and preventing wound infections. Carbon-based nanomaterials (CNMs) owing to their distinctive physicochemical and biological properties have emerged as promising platform for biomedical applications. Carbon nanotubes, graphene, fullerenes, and their nanocomposites have demonstrated broad antimicrobial activity against invasive bacteria, fungi, and viruses causing burn wound infection. The specific mechanisms that govern the antimicrobial activity of CNMs must be understood in order to ensure the safe and effective incorporation of these structures into biomaterials. However, it is challenging to decouple individual and synergistic contributions of physical, chemical, and electrical effects of CNMs on cells. This review reported on significant advances in the application of CNMs in burn wound infection and wound healing, with brief discussion on the interaction between different families of CNMs and microorganisms to assess antimicrobial performance.

Advanced drug delivery systems containing herbal components for wound healing

Management of chronic wound has an immense impact on social and economic conditions in the world. Healthcare costs, aging population, physical trauma, and comorbidities of diabetes and obesity seem to be the major factors of this increasing incidence of chronic wounds. Conditions of chronic wound could not restore functional epidermis; thus, delaying the closure of the wound opening in an expected manner. Failures in restoration of skin integrity delay healing due to changes in skin pathology, such as chronic ulceration or nonhealing. The role of different traditional medicines has been explored for use in the healing of cutaneous wounds, where several phytochemicals, such as flavonoids, alkaloids, phenolic acids, tannins are known to provide potential wound healing properties. However, the delivery of plant-based therapeutics could be improved by the novel platform of nanotechnology. Thus, the objectives of novel delivery strategies of principal bioactive from plant sources are to accelerate the wound healing process, avoid wound complications and enhance patient compliance. Therefore, the opportunities of nanotechnology-based drug delivery of natural wound healing therapeutics have been included in the present discussion with special emphasis on nanofibers, vesicular structures, nanoparticles, nanoemulsion, and nanogels.

Nanomaterials for application in wound Healing: current state-of-the-art and future perspectives

Nanoparticles are the gateway to the new era in drug delivery of biocompatible agents. Several products have emerged from nanomaterials in quest of developing practical wound healing dressings that are nonantigenic, antishear stress, and gas-exchange permeable. Numerous studies have isolated and characterised various wound healing nanomaterials and nanoproducts. The electrospinning of natural and synthetic materials produces fine products that can be mixed with other wound healing medications and herbs. Various produced nanomaterials are highly influential in wound healing experimental models and can be used commercially as well. This article reviewed the current state-of-the-art and briefly specified the future concerns regarding the different systems of nanomaterials in wound healing (i.e., inorganic nanomaterials, organic and hybrid nanomaterials, and nanofibers). This review may be a comprehensive guidance to help health care professionals identify the proper wound healing materials to avoid the usual wound complications.

Potential Use of Tailored Citicoline Chitosan-Coated Liposomes for Effective Wound Healing in Diabetic Rat Model

Purpose

This study aimed to formulate citicoline-loaded chitosan-coated liposomes (CT-CS-LPs) for topical administration and evaluated for wound healing in a diabetic animal model.

Methods

CT-LPs were formulated via a thin-film hydration approach and coated with chitosan (CS). Box-Behnken statistical design investigated the effects of lipid amount, chitosan concentration, and cholesterol amount on vesicle diameter, surface charge, and entrapment efficiency. The potential of the optimized CT-CS-LPs gel for wound healing was further evaluated in streptozocin-induced diabetic rats. The different healing stages were evaluated by several techniques, including general and special staining techniques, in addition to antibody immunohistochemistry.

Results

The optimized CT-CS-LPs obtained had a mean size of 211.6 nm, a 50.7% entrapment efficiency, and a positive surface charge of 32.1 mV. In addition, the optimized CT-CS-LPs exhibited in vitro sustained release behavior. The in vivo experiments revealed that treatment with the optimized CT-CS-LPs boosts the healing process of the skin wound in diabetic rats by reducing inflammation, accelerating re-epithelization, angiogenesis, fibroblast proliferation, and connective tissue remodeling, leading to rapid wound closure.

Conclusion

Chitosan-coated liposomes containing citicoline have emerged as a potential approach for promoting the healing process in diabetic rats. However, the therapeutic effectiveness of the suggested approach in diabetic patients needs to be investigated.

Role of copper nanoparticles in wound healing for chronic wounds: literature review

Chronic wounds are defined as wounds that fail to proceed through the normal phases of wound healing in an orderly and timely manner. The most common and inevitable impairment to wound healing is the installation of an infection, usually in the case of chronic wounds. Therefore, the objective of the present review was to identify the importance of copper nanoparticles in dressings for wound healing. Nanoparticles such as silver, gold and copper combat infectious processes through the inhibition of protein synthesis, peroxidation of the cell membrane and destroying the nucleic acids of bacteria and viruses. Among bioactive nanoparticles, copper plays a complex role in various cells, it modulates several cytokines and growth factor mechanisms of action and is essentially involved in all stages of the wound healing process. More importantly, copper plays a key role in skin regeneration and angiogenesis and accelerates the healing process through induction of vascular endothelial growth factor (VEGF) and angiogenesis by hypoxia-induced factor-1-alpha (HIF-1α) action where copper enhances HIF-1α expression and HIF-1α binding to the critical motifs in the promoter and putative enhancer regions of HIF-1-regulated genes.

Ionic liquids enable the preparation of a copper-loaded gel with transdermal delivery function for wound dressings

Antibacterial hydrogel dressings play an important role in wound healing and infection treatment. The majority of hydrogels are obtained through chemical cross-linking and complex synthesis or processing. Copper ions (Cu²⁺) have been involved in sterilization; however, their direct use may lead to high local concentrations and heavy metal toxic side effects. Herein, dopamine (DA) was polymerized in situ along a polyvinyl alcohol (PVA) chain and chelated copper ions (Cu²⁺) to form a mixture. Ionic liquid (IL) choline-glycolate (CGLY) was added to the mixture to form an ionic gel. CGLY promotes gel formation through intermolecular hydrogen bonds with the polymer chains and avoids the use of toxic chemical crosslinking agents. Meanwhile, CGLY can also promote the release of Cu²⁺ and generate hydrogel free radicals (˙OH) in the wound through chemodynamic therapy to kill drug-resistant bacteria. In addition, the excellent transdermal property of CGLY enables the released Cu²⁺ to stimulate cell migration and accelerate wound healing. The gel exhibits favorable biocompatibility and its use has been demonstrated in skin infection therapy of mice.