Nanoceutical Adjuvants as Wound Healing Material: Precepts and Prospects

Emerging Nanotherapeutic Approaches for Diabetic Wound Healing

Diabetic wounds pose a significant challenge in modern healthcare due to their chronic and complex nature, often resulting in delayed healing, infections, and, in severe cases, amputations. In recent years, nanotherapeutic approaches have emerged as promising strategies to address the unique pathophysiological characteristics of diabetic wounds. This review paper provides a comprehensive overview of the latest advancements in nanotherapeutics for diabetic wound treatment. We discuss various nanomaterials and delivery systems employed in these emerging therapies. Furthermore, we explore the integration of biomaterials to enhance the efficacy of nanotherapeutic interventions. By examining the current state-of-the-art research, challenges, and prospects, this review aims to offer valuable insights for researchers, clinicians, and healthcare professionals working in the field of diabetic wound care.

A critical overview of challenging roles of medicinal plants in improvement of wound healing technology

PURPOSE

Chronic diseases often hinder the natural healing process, making wound infections a prevalent clinical concern. In severe cases, complications can arise, potentially leading to fatal outcomes. While allopathic treatments offer numerous options for wound repair and management, the enduring popularity of herbal medications may be attributed to their perceived minimal side effects. Hence, this review aims to investigate the potential of herbal remedies in efficiently treating wounds, presenting a promising alternative for consideration.

METHODS

A literature search was done including research, reviews, systematic literature review, meta-analysis, and clinical trials considered. Search engines such as Pubmed, Google Scholar, and Scopus were used while retrieving data. Keywords like Wound healing 'Wound healing and herbal combinations', 'Herbal wound dressing', Nanotechnology and Wound dressing were used.

RESULT

This review provides valuable insights into the role of natural products and technology-based formulations in the treatment of wound infections. It evaluates the use of herbal remedies as an effective approach. Various active principles from herbs, categorized as flavonoids, glycosides, saponins, and phenolic compounds, have shown effectiveness in promoting wound closure. A multitude of herbal remedies have demonstrated significant efficacy in wound management, offering an additional avenue for care. The review encompasses a total of 72 studies, involving 127 distinct herbs (excluding any common herbs shared between studies), primarily belonging to the families Asteraceae, Fabaceae, and Apiaceae. In research, rat models were predominantly utilized to assess wound healing activities. Furthermore, advancements in herbal-based formulations using nanotechnology-based wound dressing materials, such as nanofibers, nanoemulsions, nanofiber mats, polymeric fibers, and hydrogel-based microneedles, are underway. These innovations aim to enhance targeted drug delivery and expedite recovery. Several clinical-based experimental studies have already been documented, evaluating the efficacy of various natural products for wound care and management. This signifies a promising direction in the field of wound treatment.

CONCLUSION

In recent years, scientists have increasingly utilized evidence-based medicine and advanced scientific techniques to validate the efficacy of herbal medicines and delve into the underlying mechanisms of their actions. However, there remains a critical need for further research to thoroughly understand how isolated chemicals extracted from herbs contribute to the healing process of intricate wounds, which may have life-threatening consequences. This ongoing research endeavor holds great promise in not only advancing our understanding but also in the development of innovative formulations that expedite the recovery process.

Metal-based nanoparticles: an alternative treatment for biofilm infection in hard-to-heal wounds

Metal-based nanoparticles (MNPs) are promoted as effective compounds in the treatment of bacterial infections and as possible alternatives to antibiotics. These MNPs are known to affect a broad spectrum of microorganisms using a multitude of strategies, including the induction of reactive oxygen species and interaction with the inner structures of the bacterial cells. The aim of this review was to summarise the latest studies about the effect of metal-based nanoparticles on pathogenic bacterial biofilm formed in wounds, using the examples of Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Pseudomonas aeruginosa, as well as provide an overview of possible clinical applications.

Deciphering the crosstalk between inflammation and biofilm in chronic wound healing: Phytocompounds loaded bionanomaterials as therapeutics

In terms of the economics and public health, chronic wounds exert a significant detrimental impact on the health care system. Bacterial infections, which cause the formation of highly resistant biofilms that elude standard antibiotics, are the main cause of chronic, non-healing wounds. Numerous studies have shown that phytochemicals are effective in treating a variety of diseases, and traditional medicinal plants often include important chemical groups such alkaloids, phenolics, tannins, terpenes, steroids, flavonoids, glycosides, and fatty acids. These substances are essential for scavenging free radicals which helps in reducing inflammation, fending off infections, and hastening the healing of wounds. Bacterial species can survive in chronic wound conditions because biofilms employ quorum sensing as a communication technique which regulates the expression of virulence components. Fortunately, several phytochemicals have anti-QS characteristics that efficiently block QS pathways, prevent drug-resistant strains, and reduce biofilm development in chronic wounds. This review emphasizes the potential of phytocompounds as crucial agents for alleviating bacterial infections and promoting wound healing by reducing the inflammation in chronic wounds, exhibiting potential avenues for future therapeutic approaches to mitigate the healthcare burden provided by these challenging conditions.

Accelerated Wound Healing with a Diminutive Scar through Cocrystal Engineered Curcumin

Pharmaceutical cocrystals ( Regulatory Classification of Pharmaceutical Co-Crystals Guidance for Industry; Food and Drug Administration, 2018) are crystalline solids produced through supramolecular chemistry to modulate the physicochemical properties of active pharmaceutical ingredients (APIs). Despite their extensive development in interdisciplinary sciences, this is a pioneering study on the efficacy of pharmaceutical cocrystals in wound healing and scar reducing. Curcumin-pyrogallol cocrystal (CUR-PYR) was accordingly cherry-picked since its superior physicochemical properties adequately compensate for limitative drawbacks of curcumin (CUR). CUR-PYR has been synthesized by a liquid-assisted grinding (LAG) method and characterized via FT-IR, DSC, and PXRD analyses. In vitro antibacterial study indicated that CUR-PYR cocrystal, CUR+PYR physical mixture (PM), and PYR are more effective against both Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria in comparison with CUR. In vitro results also demonstrated that the viability of HDF and NIH-3T3 cells treated with CUR-PYR were improved more than those received CUR which is attributed to the effect of PYR in the form of cocrystal. The wound healing process has been monitored through a 15 day in vivo experiment on 75 male rats stratified into six groups: five groups treated by CUR-PYR+Vaseline (CUR-PYR.ung), CUR+PYR+Vaseline (CUR+PYR.ung), CUR+Vaseline (CUR.ung), PYR+Vaseline (PYR.ung), and Vaseline (VAS) ointments and a negative control group of 0.9% sodium chloride solution (NS). It was revealed that the wounds under CUR-PYR.ung treatment closed by day 12 postsurgery, while the wounds in other groups failed to reach the complete closure end point until the end of the experiment. Surprisingly, a diminutive scar (3.89 ± 0.97% of initial wound size) was observed in the CUR-PYR.ung treated wounds by day 15 after injury, followed by corresponding values for PYR.ung (12.08 ± 2.75%), CUR+PYR.ung (13.89 ± 5.02%), CUR.ung (16.24 ± 6.39%), VAS (18.97 ± 6.89%), and NS (20.33 ± 5.77%). Besides, investigating histopathological parameters including inflammation, granulation tissue, re-epithelialization, and collagen deposition signified outstandingly higher ability of CUR-PYR cocrystal in wound healing than either of its two constituents separately or their simple PM. It was concluded that desired solubility of the prepared cocrystal was essentially responsible for accelerating wound closure and promoting tissue regeneration which yielded minimal scarring. This prototype research suggests a promising application of pharmaceutical cocrystals for the purpose of wound healing.

Pyroelectric Janus nanomotors for synergistic electrodynamic-photothermal-antibiotic therapies of bacterial infections

Antibacterial electrotherapy is currently activated by external electric field or self-powered generators, but usually needs complicated power management circuits. Herein, near-infrared illumination (NIR) of pyroelectric nanoparticles (NPs) produces a built-in electric field to address the effectiveness and safety concerns in the antibacterial treatment. Janus tBT@PDA NPs were obtained by capping polydopamine (PDA) on tetragonal BaTiO₃ (tBT) NPs through defining the polymerization time, followed by ciprofloxacin (CIP) loading on the PDA caps to fabricate Janus tBT@PDA-Cip NPs. NIR illumination of PDA caps creates temperature variations on tBT NPs to generate photothermal and pyroelectric effects. Finite element simulation reveals a pyroelectric potential of over 1 V and sufficient reactive oxygen species (ROS) are produced to exhibit pyroelectric dynamic therapy (PEDT). The elevated temperature on one side of the Janus NPs produces thermophoretic force to drive NP motion, which enhances interactions with bacteria and overcomes limitations in the short action distance and lifespan of ROS. The pyroelectric field accelerates CIP release through weakening the π-π stacking and electrostatic interaction with PDA and also interrupts membrane potentials of bacteria to enhance CIP invasion into bacteria. The synergistic antibacterial effect of pyroelectric tBT@PDA-Cip NPs causes the fully recovery of S. aureus-infected skin wounds and regeneration of intact epidermis, blood vessels and hair follicles, while no obvious pathological change or inflammatory lesion is detected in the major organs. Thus, the pyroelectric Janus nanomotors demonstrate synergistic PEDT/photothermal/antibiotic effects to enhance antibacterial efficacy while avoiding the necessity of excessive heat, ROS and antibiotic doses. STATEMENT OF SIGNIFICANCE: Antibacterial treatment is challenged by antibiotics-derived side effects and the evolution of resistant strains. Phototherapy is commonly associated with excessive heat and oxidative stress, and their combinations with other agents are especially encouraged to strengthen antibacterial efficacy while alleviating the associated side effects. Electric field is another activator to generate antibacterial abilities, but usually requires complicated power management and bulk electrodes, making it inconvenient in a biological setup. To address these challenges, we propose a strategy to generate microelectric field on nanoparticles themselves and achieve synergistic electrodynamic-photothermal-antibiotic therapies. The pyroelectric effect weakens interactions between nanoparticles and antibiotics to accelerate drug release, and the built-in pyroelectric field increases membrane fluidity to enhance bacterial uptake of antibiotics.

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

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

Application of Stichopus hermanni Nanoparticle Gel in the Healing of Traumatic Ulcers

OBJECTIVE

 The aim of this research was to investigate the use of Stichopus herrmanni nanoparticle gel on the ulcer healing process by observing blood vessels, fibroblasts, and Collagen type-I (COL-1) expression on the 4 and 7th days after trauma.

MATERIALS AND METHODS

 Gold sea cucumber (Stichopus herrmanni) powder was processed by freeze-drying method, then by high-energy milling to form nanoparticle size, and then with CMC 2% to make hydrogel. Traumatic ulcers were formed by induction using a burner. Five groups of male Wistar rats, each consisting of six tails, were divided into a negative control group that was given a placebo, the positive control group was given 0.2% hyaluronic acid, and the treatment group was given gold sea cucumbers with concentrations of 0.135, 0.27, and 0.54% (SH1-SH2-SH3). Fibroblast and blood vessels were examined with hematoxylin-eosin on day 3 and 7, while COL-1 expression was examined with immunohistochemistry on day 7. The rats' mucosa was taken on the 3rd and 7th days after the traumatic ulcer was formed.

STATISTICAL ANALYSIS

 The data were analyzed using a one-way analysis of variance followed by a post-hoc test with a p less than 0.05.

RESULTS

 Nanoparticles gel freeze-drying of Stichopus herrmanni increased blood vessels on day 3. Angiogenesis continued to occur, which resulted in increased fibroblast and COL-1 expression on day 7.

CONCLUSIONS

 The application of Stichopus herrmanni nanoparticle gel at 0.27% effectively increased the number of blood vessels, fibroblasts, and COL-1 expression in healing traumatic ulcers.

Characterization of an ablative fractional CO2 laser-induced wound-healing model based on in vitro 3D reconstructed skin

OBJECTIVE

This study describes the development and characterization of a novel in vitro wound-healing model based on a full-thickness reconstructed skin by exposing the tissue to fractional ablative laser treatment.

METHOD

A 3D full-thickness skin model was fabricated and treated with fractional ablative CO₂ laser. Wound-healing process was characterized by HE staining, noninvasive OCT imaging, immunostaining, as well as transepidermal water loss measurement. Cytokines and proteins involved in the inflammatory and dermal remodeling process were studied by ELISA and protein array assays.

RESULTS

Fractional ablative CO₂ treatment induced a wound zone of 9 mm in diameter, containing 56 micro-wounds with 200 μm diameter and 500-700 μm in depth on reconstructed full-thickness skin model. HE staining revealed a typical wound morphology and healing process with migration of keratinocytes, formation and extrusion of necrotic tissue, and cell inclusion in dermis, which correlates with clinical observations. Based on OCT and TEWL measurements, the re-epithelialization took place over 2 days. Laser-triggered keratinocytes proliferation and differentiation were demonstrated by activated Ki67 and Filaggrin expression respectively. Injury-invoked cytokine ICAM-1 showed instant upregulation on Day 1. Decreased epidermis thickness and depression of IGFBP-2 protein level synergistically indicated the unavoidable thermal side effects from laser treatment. Downregulated DKK-1 protein level and upregulation of α-SMA together implicated the risk of potential fibrosis post-laser treatment.

CONCLUSION

This in vitro laser wounded reconstructed skin model captured the key events of wound-healing process, could be used to investigate the mechanisms of wound-healing triggered by a commonly used beauty procedure, and also provides a valuable tool for evaluating the efficacy of novel actives for the post-procedure application.

Microenvironment-Based Diabetic Foot Ulcer Nanomedicine

Diabetic foot ulcers (DFU), one of the most serious complications of diabetes, are essentially chronic, nonhealing wounds caused by diabetic neuropathy, vascular disease, and bacterial infection. Given its pathogenesis, the DFU microenvironment is rather complicated and characterized by hyperglycemia, ischemia, hypoxia, hyperinflammation, and persistent infection. However, the current clinical therapies for DFU are dissatisfactory, which drives researchers to turn attention to advanced nanotechnology to address DFU therapeutic bottlenecks. In the last decade, a large number of multifunctional nanosystems based on the microenvironment of DFU have been developed with positive effects in DFU therapy, forming a novel concept of "DFU nanomedicine". However, a systematic overview of DFU nanomedicine is still unavailable in the literature. This review summarizes the microenvironmental characteristics of DFU, presents the main progress of wound healing, and summaries the state-of-the-art therapeutic strategies for DFU. Furthermore, the main challenges and future perspectives in this field are discussed and prospected, aiming to fuel and foster the development of DFU nanomedicines successfully.

Nano-Enabled Chronic Wound Healing Strategies: Burn and Diabetic Ulcer Wounds

The human skin serves as the body’s first line of defense against the environment. Diabetes mellitus (DM) and 2nd–4th degree burns, on the other hand, affect the skin’s protective barrier features. Burn wounds, hypermetabolic state, and hyperglycemia compromise the immune system leading to chronic wound healing. Unlike acute wound healing processes, chronic wounds are affected by reinfections which can lead to limb amputation or death. The conventional wound dressing techniques used to protect the wound and provide an optimal environment for repair have their limitations. Various nanomaterials have been produced that exhibit distinct features to tackle issues affecting wound repair mechanisms. This review discusses the emerging technologies that have been designed to improve wound care upon skin injury. To ensure rapid healing and possibly prevent scarring, different nanomaterials can be applied at different stages of healing (hemostasis, inflammation, proliferation, remodeling).

Self-redox reaction driven in situ formation of Cu2O/Ti3C2Tx nanosheets boost the photocatalytic eradication of multi-drug resistant bacteria from infected wound

BACKGROUND

MXenes with interesting optical and electrical properties have been attractive in biomedical applications such as antibacterial and anticancer agents, but their low photogeneration efficiency of reactive oxygen species (ROS) and poor stability are major concerns against microbial resistance.

METHODS

Water-dispersible single layer Ti₃C₂T_x-based MXene through etching tightly stacked MAX phase precursor using a minimally intensive layer delamination method. After addition of Cu(II) ions, the adsorbed Cu(II) ions underwent self-redox reactions with the surface oxygenated moieties of MXene, leading to in situ formation of Cu₂O species to yield Cu₂O/Ti₃C₂T_x nanosheets (heterostructures).

RESULTS

Under NIR irradiation, the Cu₂O enhanced generation of electron-hole pairs, which boosted the photocatalytic production of superoxide and subsequent transformation into hydrogen peroxide. Broad-spectrum antimicrobial performance of Cu₂O/Ti₃C₂T_x nanosheets with sharp edges is attributed to the direct contact-induced membrane disruption, localized photothermal therapy, and in situ generated cytotoxic free radicals. The minimum inhibitory concentration of Cu₂O/Ti₃C₂T_x nanosheets reduced at least tenfold upon NIR laser irradiation compared to pristine Cu₂O/Ti₃C₂T_x nanosheets. The Cu₂O/Ti₃C₂T_x nanosheets were topically administrated on the methicillin-resistant Staphylococcus aureus (MRSA) infected wounds on diabetic mice.

CONCLUSION

Upon NIR illumination, Cu₂O/Ti₃C₂T_x nanosheets eradicated MRSA and their associated biofilm to promote wound healing. The Cu₂O/Ti₃C₂T_x nanosheets with superior catalytic and photothermal properties have a great scope as an effective antimicrobial modality for the treatment of infected wounds.

Aloe vera and Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus is defined as prolonged hyperglycemia, which can harm the eyes, kidneys, and cardiovascular and neurological systems. Herbal agents and their derived supplements have been used for treatment of diabetes mellitus as a part of integrated complementary medicine for centuries. Numerous studies have considered Aloe vera (L.) Burm.f, Xanthorrhoeaceae, as an alternative medicine due to its abundant bioactive chemicals, such as alkaloids, anthraquinones, and enthrones, with therapeutical properties including antioxidant, anti-inflammatory, neuro-protective, and anti-diabetic effects. Aloe vera has received considerable attention in traditional medicine for the treatment of several diseases including diabetes mellitus. Numerous studies have investigated the effects of herbal agents on diabetes mellitus using a streptozotocin-induced diabetic model. Thereby, this article reviews the effects of Aloe vera prescription on streptozotocin-induced diabetes mellitus to provide a clear insight into the role of this medicinal plant in several biological functions, such as antioxidant, wound healing, anti-inflammatory, anti-hyperglycemic, and anti-hyperlipidemic in diabetic models.

Cold-atmospheric plasma augments functionalities of hybrid polymeric carriers regenerating chronic wounds: In vivo experiments

The skin possesses an epithelial barrier. Delivering growth factors to deeper wounds is usually rather challenging, and these typically restrict the therapeutic efficacy for chronic wound healing. Efficient healing of chronic wounds also requires abundant blood flow. Therefore, addressing these concerns is crucial. Among presently accessible biomedical materials, tailored hydrogels are favorable for translational medicine. However, these hydrogels display insufficient mechanical properties, hampering their biomedical uses. Cold-atmospheric plasma (CAP) has potent cross-linking/polymerizing abilities. The CAP was characterized spectroscopically to identify excited radiation and species (hydroxyl and UV). CAP was used to polymerize pyrrole (creating Ppy) and crosslink hybrid polymers (Ppy, hyaluronic acid (HA), and gelatin (GEL)) as a multimodal dressing for chronic wounds (CAP-Ppy/GEL/HA), which were used to incorporate therapeutic platelet proteins (PPs). Herein, the physicochemical and biological features of the developed CAP-Ppy/GEL/HA/PP complex were assessed. CAP-Ppy/GEL/HA/PPs had positive impacts on wound healing in vitro. In addition, the CAP-Ppy/GEL/HA complex has improved mechanical aspects, therapeutics sustained-release/retention effect, and near-infrared (NIR)-driven photothermal-hyperthermic effects on lesions that drive the expression of heat-shock protein (HSP) with anti-inflammatory properties for boosted restoration of diabetic wounds in vivo. These in vitro and in vivo outcomes support the use of CAP-Ppy/GEL/HA/PPs for diabetic wound regeneration.

Eugenol-acacia gum-based bifunctional nanofibers as a potent antifungal transdermal substitute

Aim: Fungal biofilms interfere with the wound healing processes. Henceforth, the study aims to fabricate a biomaterial-based nano-scaffold with the dual functionalities of wound healing and antibiofilm activity. Methods: Nanofibers comprising acacia gum, polyvinyl alcohol and inclusion complex of eugenol in β-cyclodextrin (EG-NF) were synthesized using electrospinning. Antibiofilm studies were performed on Candida species, and the wound-healing activity was evaluated through an in vivo excision wound rat model. Results: The EG-NF potentially eradicated the mature biofilm of Candida species and their clinical isolates. Further, EG-NF also enhanced the re-epithelization and speed of wound healing in in vivo rat experiments. Conclusion: The study established the bifunctional applications of eugenol nanofibers as a transdermal substitute with antifungal potency.