Curcumin-loaded chitosan nanoparticles promote diabetic wound healing via attenuating inflammation in a diabetic rat model

Phytoconstituents as modulators of NF-κB signalling: Investigating therapeutic potential for diabetic wound healing

The NF-κB pathway plays a pivotal role in impeding the diabetic wound healing process, contributing to prolonged inflammation, diminished angiogenesis, and reduced proliferation. In contrast to modern synthetic therapies, naturally occurring phytoconstituents are well-studied inhibitors of the NF-κB pathway that are now attracting increased attention in the context of diabetic wound healing because of lower toxicity, better safety and efficacy, and cost-effectiveness. This study explores recent research on phytoconstituent-based therapies and delve into their action mechanisms targeting the NF-κB pathway and potential for assisting effective healing of diabetic wounds. For this purpose, we have carried out surveys of recent literature and analyzed studies from prominent databases such as Science Direct, Scopus, PubMed, Google Scholar, EMBASE, and Web of Science. The classification of phytoconstituents into various categorie such as: alkaloids, triterpenoids, phenolics, polyphenols, flavonoids, monoterpene glycosides, naphthoquinones and tocopherols. Noteworthy phytoconstituents, including Neferine, Plumbagin, Boswellic acid, Genistein, Luteolin, Kirenol, Rutin, Vicenin-2, Gamma-tocopherol, Icariin, Resveratrol, Mangiferin, Betulinic acid, Berberine, Syringic acid, Gallocatechin, Curcumin, Loureirin-A, Loureirin-B, Lupeol, Paeoniflorin, and Puerarin emerge from these studies as promising agents for diabetic wound healing through the inhibition of the NF-κB pathway. Extensive research on various phytoconstituents has revealed how they modulate signalling pathways, including NF-κB, studies that demonstrate the potential for development of therapeutic phytoconstituents to assist healing of chronic diabetic wounds.

Dermal derived matrix hydrogel loaded with curcumin improved wound healing in a diabetic rat model

There is a need in clinical practice for new wound healing techniques to address full thickness skin injuries, particularly in individuals with diabetes. Herein we investigated whether dermal derived matrix hydrogel (DMH) loaded with curcumin (Cur) could promote healing in diabetic rats. Sixty diabetic rats were randomly assigned into the non-treated group, DMH group, Cur group, and DMH+Cur group. According to the phases of wound healing, sampling was done on days 7, 14, and 21 for further assessments. Our results indicated that the wound contraction rate, new epidermal length and thickness, number of fibroblasts and vascular length, collagen deposition, and strength properties of the healed wounds were meaningfully increased in the treatment groups than in the non-treated group, and these changes were more obvious in the DMH+Cur ones. In addition, the expression of VEGF and IL-10 genes were meaningfully upregulated in all treatment groups compared to the non-treated group and were greater in the DMH+Cur group. This is while the number of neutrophils and expression levels of TNF-α and IL-1β genes decreased more significantly in the DMH+Cur group compared to the other groups. In conclusion, it was found that using both DMH and curcumin has a greater impact on diabetic wound healing.

Triboelectric-Responsive Drug Delivery Hydrogel for Accelerating Infected Wound Healing

Electrotherapy is of great interest in the field of tissue repair as an effective, well-tolerated, and noninvasive treatment. Triboelectric nanogenerator (TENG) has shown advantages in promoting wound healing due to its peak output characteristic and low Joule heating effect. However, it is limited in infected wound healing due to poor antimicrobial capacity. Here, a wearable triboelectric stimulator (WTS) is developed that consists of a flexible TENG (F-TENG) and a triboelectric-responsive drug delivery hydrogel (TR-DDH) for healing of bacterium-infected wounds. F-TENG can generate pulsed current to wounds by converting mechanical energy from body movements. Polypyrrole is prone to reduction and volume contraction under electrical stimulation, resulting in desorption of curcumin nanoparticles (CUR NPs) from the polypyrrole in TR-DDH. Therefore, the highly efficient and controllable release of CUR NPs can be achieved by triboelectric stimulation. According to the in vitro and in vivo experiments, WTS has the greatest antimicrobial effect and the fastest promotion of infected wound healing compared to treatment with electrical stimulation or curcumin. Finally, the safety assessment demonstrates that the WTS has excellent tissue safety for chronic wound healing. Synergistic therapy with WTS provides an efficient strategy for chronic wound healing and smart-responsive drug delivery systems.

Biopolymer based nanoparticles and their therapeutic potential in wound healing - A review

Nanoparticles (NPs) have been extensively investigated for their potential in nanomedicine. There is a significant level of enthusiasm about the potential of NPs to bring out a transformative impact on modern healthcare. NPs can serve as effective wound dressings or delivery vehicles due to their antibacterial and pro-wound-healing properties. Biopolymer-based NPs can be manufactured using various food-grade biopolymers, such as proteins, polysaccharides, and synthetic polymers, each offering distinct properties suitable for different applications which include collagen, polycaprolactone, chitosan, alginate, and polylactic acid, etc. Their biodegradable and biocompatible nature renders them ideal nanomaterials for applications in wound healing. Additionally, the nanofibers containing biopolymer-based NPs have shown excellent anti-bacterial and wound healing activity like silver NPs. These NPs represent a paradigm shift in wound healing therapies, offering targeted and personalized solutions for enhanced tissue regeneration and accelerated wound closure. The current review focuses on biopolymer NPs with their applications in wound healing.

Gelatin Microspheres Based on H8-Loaded Macrophage Membrane Vesicles to Promote Wound Healing in Diabetic Mice

Diabetic wound healing remains a worldwide challenge for both clinicians and researchers. The high expression of matrix metalloproteinase 9 (MMP9) and a high inflammatory response are indicative of poor diabetic wound healing. H8, a curcumin analogue, is able to treat diabetes and is anti-inflammatory, and our pretest showed that it has the potential to treat diabetic wound healing. However, H8 is highly expressed in organs such as the liver and kidney, resulting in its unfocused use in diabetic wound targeting. (These data were not published, see Table S1 in the Supporting Information.) Accordingly, it is important to pursue effective carrier vehicles to facilitate the therapeutic uses of H8. The use of H8 delivered by macrophage membrane-derived nanovesicles provides a potential strategy for repairing diabetic wounds with improved drug efficacy and fast healing. In this study, we fabricated an injectable gelatin microsphere (GM) with sustained MMP9-responsive H8 macrophage membrane-derived nanovesicles (H8NVs) with a targeted release to promote angiogenesis that also reduces oxidative stress damage and inflammation, promoting diabetic wound healing. Gelatin microspheres loaded with H8NV (GMH8NV) stimulated by MMP9 can significantly facilitate the migration of NIH-3T3 cells and facilitate the development of tubular structures by HUVEC in vitro. In addition, our results demonstrated that GMH8NV stimulated by MMP9 protected cells from oxidative damage and polarized macrophages to the M2 phenotype, leading to an inflammation inhibition. By stimulating angiogenesis and collagen deposition, inhibiting inflammation, and reducing MMP9 expression, GMH8NV accelerated wound healing. This study showed that GMH8NVs were targeted to release H8NV after MMP9 stimulation, suggesting promising potential in achieving satisfactory healing in diabetic treatment.

Preparation and characterization of 3D bioprinted gelatin methacrylate hydrogel incorporated with curcumin loaded chitosan nanoparticles for in vivo wound healing application

This study developed a biomimetic composite bioink consisting of gelatin methacrylate (GelMA) /chitosan nanoparticles (CSNPs) for extrusion-based 3D bioprinting. Additionally, curcumin(Cur)-loaded nanoparticles were incorporated which increased the proliferation and antibacterial activity of biomimetic skin constructs. The hydrogel, curcumin-loaded NPs, and the biocomposite was characterized chemically and physically. The results indicated proper modified gelatin with tunable physical characteristics, e.g., swelling ratio and biodegradability up to 1200 % and 25 days, respectively. In addition, the characterized CSNPs showed good distribution with a size of 370 nm and a zeta potential of 41.1 mV. We investigated the mechanical and cytocompatibility properties of chitosan nanoparticles encapsulated in hydrogel for emulating an extracellular matrix suitable for skin tissue engineering. CSNPs entrapped in GelMA (15 % w/v) exhibited controlled drug release during 5 days, which was fitted into various kinetic models to study the mass transfer mechanism behavior. Also, the composite hydrogels were effective as a barrier against both gram-positive and gram-negative bacteria at a concentration of 50 μg/ml nanoparticles in GelMA 15 %. Furthermore, the biocomposite was applied on Wistar rats for wound healing. As a result, this study provides a GelMA-NP50-Cur3 scaffold that promotes cell proliferation and decreases microbial infections in wounds.

Enhanced drug delivery and wound healing potential of berberine-loaded chitosan-alginate nanocomposite gel: characterization and in vivo assessment

Berberine-encapsulated polyelectrolyte nanocomposite (BR-PolyET-NC) gel was developed as a long-acting improved wound healing therapy. BR-PolyET-NC was developed using an ionic gelation/complexation method and thereafter loaded into Carbopol gel. Formulation was optimized using Design-Expert® software implementing a three-level, three-factor Box Behnken design (BBD). The concentrations of polymers, namely, chitosan and alginate, and calcium chloride were investigated based on particle size and %EE. Moreover, formulation characterized in vitro for biopharmaceutical performances and their wound healing potency was evaluated in vivo in adult BALB/c mice. The particle distribution analysis showed a nanocomposite size of 71 ± 3.5 nm, polydispersity index (PDI) of 0.45, ζ-potential of +22 mV, BR entrapment of 91 ± 1.6%, and loading efficiency of 12.5 ± 0.91%. Percentage drug release was recorded as 89.50 ± 6.9% with pH 6.8, thereby simulating the wound microenvironment. The in vitro investigation of the nanocomposite gel revealed uniform consistency, well spreadability, and extrudability, which are ideal for topical wound use. The analytical estimation executed using FT-IR, DSC, and X-ray diffraction (XRD) indicated successful formulation with no drug excipients and without the amorphous state. The colony count of microbes was greatly reduced in the BR-PolyET-NC treated group on the 15th day from up to 6 CFU compared to 20 CFU observed in the BR gel treated group. The numbers of monocytes and lymphocytes counts were significantly reduced following healing progression, which reached to a peak level and vanished on the 15th day. The observed experimental characterization and in vivo study indicated the effectiveness of the developed BR-PolyET-NC gel toward wound closure and healing process, and it was found that >99% of the wound closed by 15th day, stimulated via various anti-inflammatory and angiogenic factors.

Molecular pathways of NF-ĸB and NLRP3 inflammasome as potential targets in the treatment of inflammation in diabetic wounds: A review

Diabetic wounds are slow healing wounds characterized by disordered healing processes and frequently take longer than three months to heal. One of the defining characteristics of impaired diabetic wound healing is an abnormal and unresolved inflammatory response, which is primarily brought on by abnormal macrophage innate immune signaling activation. The persistent inflammatory state in a diabetic wound may be attributed to inflammatory pathways such as nuclear factor kappa B (NF-ĸB) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, which have long been associated with inflammatory diseases. Despite the available treatments for diabetic foot ulcers (DFUs) that include debridement, growth factor therapy, and topical anti-bacterial agents, successful wound healing is still hampered. Further understanding of the molecular mechanism of these pathways could be useful in designing potential therapeutic targets for diabetic wound healing. This review provides an update and novel insights into the roles of NF-ĸB and NLRP3 pathways in the molecular mechanism of diabetic wound inflammation and their potential as therapeutic targets in diabetic wound healing.

Curcumin-loaded chitosan nanoparticles alleviate fenpropathrin-induced hepatotoxicity by regulating lipogenesis and pyroptosis in rats

In this study, the probable alleviative role of curcumin (CMN) (50 mg/kg b.wt) or curcumin-loaded chitosan nanoparticle (CLC-NP) (50 mg/kg b.wt) was assessed against the hepatotoxic effect of a widely used pyrethroid insecticide, fenpropathrin (FEN) (15 mg/kg b.wt) in rats in a 60-day experiment. The results revealed that CMN and CLC-NP significantly suppressed the FEN-induced increment in serum hepatic enzyme activities (ALT, AST, and ALP) and hyperbilirubinemia. Moreover, FEN-associated dyslipidemia, hepatic oxidative stress, and altered hepatic histology were significantly rescued by CMN and CLC-NP. Furthermore, the increased TNF-α and Caspase-3 immunoexpression in hepatic tissues of FEN-exposed rats was significantly reduced in CMN and CLC-NP-treated ones. FEN exposure significantly upregulated the pyroptosis-related genes, including GSDMD, Casp-1, Casp-3, Casp-8, IL-18, TNF-α, IL-1β, and NF-κB and altered the expression of lipogenesis-related genes including SREBP-1c, PPAR-α, MCP1, and FAS in the hepatic tissues. Nevertheless, the earlier disturbances in gene expression were corrected in CMN and CLC-NP-treated groups. Of note, compared to CMN, CLC-NP was more effective at inhibiting oxidative damage and controlling lipogenesis and pyroptosis in the hepatic tissues of FEN-exposed rats. Conclusively, the current study findings proved the superior and useful role of CLC-NP in combating pollutants associated with hepatic dysfunction.

Chitosan Particles Complexed with CA5-HIF-1α Plasmids Increase Angiogenesis and Improve Wound Healing

Wound therapies involving gene delivery to the skin have significant potential due to the advantage and ease of local treatment. However, choosing the appropriate vector to enable successful gene expression while also ensuring that the treatment's immediate material components are conducive to healing itself is critical. In this study, we utilized a particulate formulation of the polymer chitosan (chitosan particles, CPs) as a non-viral vector for the delivery of a plasmid encoding human CA5-HIF-1α, a degradation resistant form of HIF-1α, to enhance wound healing. We also compared the angiogenic potential of our treatment (HIF/CPs) to that of chitosan particles containing only the plasmid backbone (bb/CPs) and the chitosan particle vector alone (CPs). Our results indicate that chitosan particles exert angiogenic effects that are enhanced with the human CA5-HIF-1α-encoded plasmid. Moreover, HIF/CPs enhanced wound healing in diabetic db/db mice (p < 0.01), and healed tissue was found to contain a significantly increased number of blood vessels compared to bb/CPs (p < 0.01), CPs (p < 0.05) and no-treatment groups (p < 0.01). Thus, this study represents a method of gene delivery to the skin that utilizes an inherently pro-wound-healing polymer as a vector for plasmid DNA that has broad application for the expression of other therapeutic genes.

Biological macromolecules-based nanoformulation in improving wound healing and bacterial biofilm-associated infection: A review

A chronic wound is a serious complication associated with diabetes mellitus and is difficult to heal due to high glucose levels, oxidative stress, and biofilm-associated microbial infection. The structural complexity of microbial biofilm makes it impossible for antibiotics to penetrate the matrix, hence conventional antibiotic therapies became ineffective in clinical settings. This demonstrates an urgent need to find safer alternatives to reduce the prevalence of chronic wound infection associated with microbial biofilm. A novel approach to address these concerns is to inhibit biofilm formation using biological-macromolecule based nano-delivery system. Higher drug loading efficiency, sustained drug release, enhanced drug stability, and improved bioavailability are advantages of employing nano-drug delivery systems to prevent microbial colonization and biofilm formation in chronic wounds. This review covers the pathogenesis, microbial biofilm formation, and immune response to chronic wounds. Furthermore, we also focus on macromolecule-based nanoparticles as wound healing therapies to reduce the increased mortality associated with chronic wound infections.

Application of combined photobiomodulation and curcumin-loaded iron oxide nanoparticles considerably enhanced repair in an infected, delayed-repair wound model in diabetic rats compared to either treatment alone

Herein, we attempted to evaluate the therapeutic potential of photobiomodulation (PBM) and curcumin-loaded iron nanoparticles (CUR), alone and in combination, on wound closure rate (WCR), microbial flora by measuring colony-forming units (CFUs), the stereological and biomechanical properties of repairing wounds in the maturation stage of the wound healing course in an ischemic infected delayed healing wound model (IIDHWM) of type I diabetic (TIDM) rats. There were four groups: group 1 was the control, group 2 received CUR, rats in group 3 were exposed to PBM (80 Hz, 890 nm, and 0.2 J/cm2), and rats in group 4 received both PBM and CUR (PBM + CUR). We found CFU was decreased in groups 2, 3, and 4 compared to group 1 (p = 0.000 for all). Groups 2, 3, and 4 showed a considerable escalation in WCR compared to group 1 (p = 0.000 for all). In terms of wound strength parameters, substantial increases in bending stiffness and high-stress load were observed in groups 2, 3, and 4 compared to group 1 (p = 0.000 for all). Stereological examinations revealed decreases in neutrophil and macrophage counts and increases in fibroblast counts in groups 2, 3, and 4compared  to group 1 (p = 0.000 for all). Blood vessel counts were more dominant in the PBM and PBM + CUR groups over group 1 (p = 0.000 for all). CFU and wound strength as well as macrophage, neutrophil, and fibroblast counts were found to be improved in the PBM + CUR and PBM groups compared to the CUR group (ranging from p = 0.000 to p < 0.05). Better results were achieved in the PBM + CUR  treatment  over the PBM therapy. We determined therapy with PBM + CUR, PBM alone, and CUR alone substantially accelerated diabetic wound healing in an IIDHWM of TIDM rats compared to control  group. Concomitantly, the PBM + CUR and PBM groups attained significantly enhanced results for WCR, stereological parameters, and wound strength than the CUR group, with the PBM + CUR results being superior to those of the PBM group.

Curcumin in exfoliated layered double hydroxide nanoparticles: Pre-clinical evaluation as lung cancer nanomedicine

Rationally designed ∼ 100 nm sized curcumin (CRC) loaded exfoliated layered double hydroxide nanoparticles (X-LDH/CRC-NPs) have been tested for its suitability as nanomedicine in non-small cell lung cancer (NSCLC) cell lines (A549 and NCI-H460) resulting enhanced apoptosis. Preclinical evaluation on A549 tumor bearing nude mouse model confirmed that such a well-designed X-LDH/CRC NPs would be highly advantageous for treating lung cancers.

Curcumin-based nanoformulations alleviate wounds and related disorders: A comprehensive review

Despite numerous advantages, curcumin's (CUR) low solubility and low bioavailability limit its employment as a free drug. CUR-incorporated nanoformulation enhances the bioavailability and angiogenesis, collagen deposition, fibroblast proliferation, reepithelization, collagen synthesis, neovascularization, and granulation tissue formation in different wounds. Designing nanoformulations with controlled-release properties ensure the presence of CUR in the defective area during treatment. Different nanoformulations encompassing nanofibers, nanoparticles (NPs), nanospray, nanoemulsion, nanosuspension, nanoliposome, nanovesicle, and nanomicelle were described in the present study comprehensively. Moreover, for some other systems which contain nano-CUR or CUR nanoformulations, including some nanofibers, films, composites, scaffolds, gel, and hydrogels seems the CUR-loaded NPs incorporation has better control of the sustained release, and thereby, the presence of CUR until the final stages of wound healing is more possible. Incorporating CUR-loaded chitosan NPs into nanofiber increased the release time, while 80% of CUR was released during 240 h (10 days). Therefore, this system can guarantee the presence of CUR during the entire healing period. Furthermore, porous structures such as sponges, aerogels, some hydrogels, and scaffolds disclosed promising performance. These architectures with interconnected pores can mimic the native extracellular matrix, thereby facilitating attachment and infiltration of cells at the wound site, besides maintaining a free flow of nutrients and oxygen within the three-dimensional structure essential for rapid and proper wound healing, as well as enhancing mechanical strength.

Recent advances in curcumin-based nanoformulations in diabetes

Diabetes is predicted to affect 700 million people by the year 2045. Despite the potential benefits for diabetics, curcumin's low bioavailability significantly reduces its utility. However, newer formulation methods of decreasing particle size, such as through nanotechnological advances, may improve curcumin's bioavailability and cell-absorption properties. Various curcumin nanoformulations such as nanofibers, nanoparticles-like nanostructured lipid carriers (NLCs), Solid Self-Nanoemulsifying Drug Delivery Systems (S-SNEDDS), and nanohydrogels have been evaluated. These studies reported increased bioavailability of nanoformulated curcumin compared to free curcumin. Here, we provide a detailed review of the antidiabetic effects of nanocurcumin compounds and subsequent effects on diabetic complications. Overall, various nanocurcumin formulations highly increase curcumin water-solubility and bioavailability, and these safe formulations can positively affect managing some diabetes-related manifestations and complications. Moreover, nanocurcumin efficacy in various diabetes complications is discussed. These complications included inflammation, neuropathy, depression, anxiety, keratopathy, cataract, cardiomyopathy, myocardial infarction (MI), nephropathy, erectile dysfunction, and diabetic wound. Moreover, several nanocurcumin formulations improved wound healing in the diabetic. However, few studies have been performed in humans, and most results have been reported from cellular and animal studies. Therefore, more human studies are needed to prove the antidiabetic effects of nanocurcumin.

Pathology and Treatment of Psoriasis Using Nanoformulations

Psoriasis (PSO) is an inflammatory skin condition that causes a variety of diseases and significantly decreases the life characteristics of patients, and substantially diminishes patients' quality of life. PSO usually impairs the skin and is linked to various disorders. Inflammation pathology does not only damage psoriatic skin; it shows how PSO impinges other body parts. Many variables interact with one another and can impact the etiology of psoriasis directly or indirectly. PSO has an effect on approximately 2% of the world's population, and significant progress has been made in comprehending and treating the alternative PSO by novel drug delivery systems. Topical, systemic, biological, biomaterials, and phototherapy are some of the useful therapies for PSO. Nonetheless, topical treatments remain the gold standard for treating moderate PSO. The applicability of several nanocarrier systems, such as lipid nanoparticles, metallic nanoparticles, and certain phytocompounds, has been briefly explored. The present review focuses mainly on traditional therapeutic strategies as well as on breakthroughs in nanoformulations and drug delivery methods for several anti-psoriatic drugs.

Antiangiogenic Potential of Troxerutin and Chitosan Loaded Troxerutin on Chorioallantoic Membrane Model

Angiogenesis is crucial to the development of cancer because it allows the transport of oxygen, nutrients, and growth factors as well as the spread of tumors to distant organs. Inhibitors of angiogenesis prevent the formation of blood vessels that allow tumor cells to shrink, rather than promote tumor growth. Chitosan acts as a carrier for many drugs, since the compound has various properties such as biodegradable, less toxicity, more stable, simple, easy to prepare, and biocompatible. The aim of the current study was to evaluate the efficacy of chitosan nanoparticles encapsulated with troxerutin (Chi-Trox NPs) against angiogenesis and cancer in ova chick chorioallantoic membrane (CAM) model. Chi-Trox NPs were synthesized using a nanoprecipitation method and were characterized by various analyses. 24 hours' fertilized eggs (6 eggs/group) were treated with native Trox and Chi-Trox NPs for 5 days. The antiangiogenic activity was evaluated by morphometric, histopathological, immunohistochemical (CD104 and vimentin), and mRNA expression of MMP and FGF2 using RT-PCR. The anticancer activity was evaluated by histopathological, immunohistochmical (CD44), and mRNA expression of FGF2 and MMP. The synthesized chitosan NPs were successfully encapsulated with troxerutin, and the loading efficiency of chitosan NPs was found to be 86.4 ± 0.12% and 13.2 ± 0.16% respectively. Morphometric analysis of Chi-Trox NPs showed a considerable decrease in the number of blood vessels compared with control and native Trox. The histopathological observation of CAM confirmed that Chi-Trox NPs induce a significant reduction in inflammatory cells and the thickness of blood capillaries compared to control and native Trox. The immunohistochemical evaluation of CAM revealed Chi-Trox decreased CD104, vimentin and CD44 protein levels were compared with control and native Trox. Furthermore, the mRNA expression levels of FGF2 and MMP were significantly downregulated compared to their native forms. From the obtained results, Chi-Trox NPs possess significant inhibition of angiogenesis and can be used as therapeutic agents for cancer in the future.

Why traditional herbal medicine promotes wound healing: Research from immune response, wound microbiome to controlled delivery

Impaired wound healing in chronic wounds has been a significant challenge for clinicians and researchers for decades. Traditional herbal medicine (THM) has a long history of promoting wound healing, making them culturally accepted and trusted by a great number of people in the world. However, for a long time, the understanding of herbal medicine has been limited and incomplete, particularly in the allopathic medicine-dominated research system. The therapeutic effects of individual components isolated from THM are found less pronounced compared to synthetic chemical medicine, and the clinical efficacy is always inferior to herbs. In the present article, we review and discuss underlying mechanisms of the skin microbiome involved in the wound healing process; THM in regulating immune responses and commensal microbiome. We additionally propose few pioneer ideas and studies in the development of therapeutic strategies for controlled delivery of herbal medicine. This review aims to promote wound care with a focus on wound microbiome, immune response, and topical drug delivery systems. Finally, future development trends, challenges, and research directions are discussed.

A Comprehensive Review of the Application of Nanoparticles in Diabetic Wound Healing: Therapeutic Potential and Future Perspectives

Diabetic wounds are one of the most challenging public health issues of the 21st century due to their inadequate vascular supply, bacterial infections, high levels of oxidative stress, and abnormalities in antioxidant defenses, whereas there is no effective treatment for diabetic wounds. Due to the distinct properties of nanoparticles, such as their small particle size, elevated cellular uptake, low cytotoxicity, antibacterial activity, good biocompatibility, and biodegradability. The application of nanoparticles has been widely used in the treatment of diabetic wound healing due to their superior anti-inflammatory, antibacterial, and antioxidant activities. These nanoparticles can also be loaded with various agents, such as organic molecules (eg, exosomes, small molecule compounds, etc.), inorganic molecules (metals, nonmetals, etc.), or complexed with various biomaterials, such as smart hydrogels (HG), chitosan (CS), and hyaluronic acid (HA), to augment their therapeutic potential in diabetic wounds. This paper reviews the therapeutic potential and future perspective of nanoparticles in the treatment of diabetic wounds. Together, nanoparticles represent a promising strategy in the treatment of diabetic wound healing. The future direction may be to develop novel nanoparticles with multiple effects that not only act in wound healing at all stages of diabetes but also provide a stable physiological environment throughout the wound-healing process.

Protective effects of curcumin on ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is a term used to describe phenomena connected to the dysfunction of various tissue damage due to reperfusion after ischemic injury. While I/R may result in systemic inflammatory response syndrome or multiple organ dysfunction syndrome, there is still a long way to improve therapeutic outcomes. A number of cellular metabolic and ultrastructural alterations occur by prolonged ischemia. Ischemia increases the expression of proinflammatory gene products and bioactive substances within the endothelium, such as cytokines, leukocytes, and adhesion molecules, even as suppressing the expression of other "protective" gene products and substances, such as thrombomodulin and constitutive nitric oxide synthase (e.g., prostacyclin, nitric oxide [NO]). Curcumin is the primary phenolic pigment derived from turmeric, the powdered rhizome of Curcuma longa. Numerous studies have shown that curcumin has strong antiinflammatory and antioxidant characteristics. It also prevents lipid peroxidation and scavenges free radicals like superoxide anion, singlet oxygen, NO, and hydroxyl. In our study, we highlight the mechanisms of protective effects of curcumin against I/R injury in various organs.

Wound-Healing Effects of Curcumin and Its Nanoformulations: A Comprehensive Review

Wound healing is an intricate process of tissue repair or remodeling that occurs in response to injury. Plants and plant-derived bioactive constituents are well explored in the treatment of various types of wounds. Curcumin is a natural polyphenolic substance that has been used since ancient times in Ayurveda for its healing properties, as it reduces inflammation and acts on several healing stages. Several research studies for curcumin delivery at the wound site reported the effectiveness of curcumin in eradicating reactive oxygen species and its ability to enhance the deposition of collagen, granulation tissue formation, and finally, expedite wound contraction. Curcumin has been widely investigated for its wound healing potential but its lower solubility and rapid metabolism, in addition to its shorter plasma half-life, have limited its applications in wound healing. As nanotechnology has proven to be an effective technique to accelerate wound healing by stimulating appropriate mobility through various healing phases, curcumin-loaded nanocarriers are used for targeted delivery at the wound sites. This review highlights the potential of curcumin and its nanoformulations, such as liposomes, nanoparticles, and nano-emulsions, etc. in wound healing. This paper emphasizes the numerous biomedical applications of curcumin which collectively prepare a base for its antibiofilm and wound-healing action.

Demystifying phytoconstituent-derived nanomedicines in their immunoregulatory and therapeutic roles in inflammatory diseases

In the past decades, phytoconstituents have appeared as critical mediators for immune regulations among various diseases, both in eukaryotes and prokaryotes. These bioactive molecules, showing a broad range of biological functions, would hold tremendous promise for developing new therapeutics. The discovery of phytoconstituents' capability of functionally regulating immune cells and associating cytokines, suppressing systemic inflammation, and remodeling immunity have rapidly promoted the idea of their employment as anti-inflammatory agents. In this review, we discuss various roles of phyto-derived medicines in the field of inflammatory diseases, including chronic inflammation, autoimmune diseases, and acute inflammatory disease such as COVID-19. Nevertheless, traditional phyto-derived medicines often concurred with their clinical administration limitations, such as their lack of cell specificity, inefficient cytoplasmic delivery, and rapid clearance by the immune system. As alternatives, phyto-derived nano-approaches may provide significant benefits. Both unmodified and engineered nanocarriers present the potential to serve as phytoconstituent delivery systems to improve therapeutic physio-chemical properties and pharmacokinetic profiles. Thus, the development of phytoconstituents' nano-delivery designs, their new and perspective approaches for therapeutical applications are elaborated herein.

How Curcumin Targets Inflammatory Mediators in Diabetes: Therapeutic Insights and Possible Solutions

Diabetes mellitus is a multifactorial chronic metabolic disorder, characterized by altered metabolism of macro-nutrients, such as fats, proteins, and carbohydrates. Diabetic retinopathy, diabetic cardiomyopathy, diabetic encephalopathy, diabetic periodontitis, and diabetic nephropathy are the prominent complications of diabetes. Inflammatory mediators are primarily responsible for these complications. Curcumin, a polyphenol derived from turmeric, is well known for its anti-oxidant, anti-inflammatory, and anti-apoptotic properties. The regulation of several signaling pathways effectively targets inflammatory mediators in diabetes. Curcumin’s anti-inflammatory and anti-oxidative activities against a wide range of molecular targets have been shown to have therapeutic potential for a variety of chronic inflammatory disorders, including diabetes. Curcumin’s biological examination has shown that it is a powerful anti-oxidant that stops cells from growing by releasing active free thiol groups at the target location. Curcumin is a powerful anti-inflammatory agent that targets inflammatory mediators in diabetes, and its resistant form leads to better therapeutic outcomes in diabetes complications. Moreover, Curcumin is an anti-oxidant and NF-B inhibitor that may be useful in treating diabetes. Curcumin has been shown to inhibit diabetes-related enzymes, such as a-glucosidase, aldose reductase and aldose reductase inhibitors. Through its anti-oxidant and anti-inflammatory effects, and its suppression of vascular endothelial development and nuclear transcription factors, curcumin has the ability to prevent, or reduce, the course of diabetic retinopathy. Curcumin improves insulin sensitivity by suppressing phosphorylation of ERK/JNK in HG-induced insulin-resistant cells and strengthening the PI3K-AKT-GSK3B signaling pathway. In the present article, we aimed to discuss the anti-inflammatory mechanisms of curcumin in diabetes regulated by various molecular signaling pathways.

Properties of the acellular porcine cornea crosslinked with UVA/riboflavin as scaffolds for Boston Keratoprosthesis

The Boston Keratoprosthesis type I (B-KPro) is widely used in the world, but the lack of donor corneas limits its application. This study aims to prepare the acellular porcine cornea (APC) crosslinked with ultraviolet A (UVA)/riboflavin instead of donor corneas as the scaffold for B-KPro. Decellularization of freeze-thaw combined with biological enzymes resulted in approximately 5 ng/mg DNA residue, the a-Gal removal rate of 99%, and glycosaminoglycans retention at a high level of 46.66 ± 2.59 mg/mg. UVA/ riboflavin cross-linking was adopted to induce the formation of new chemical bonds between adjacent collagen chains in the corneal stroma to improve the mechanical properties and resistance to enzymatic hydrolysis. Through comprehensive analysis of the biomechanics, enzyme degradation, immunogenicity and histological structure of the APC crosslinked at different times, CL3 (irradiation conditions, 365 nm, 3 mW/cm, 80 min, both sides) was selected and transplanted into the rabbit cornea model through interlamellar keratoplasty and penetrating keratoplasty as the scaffold of the B-KPro. Compared with the native porcine cornea (NPC) and APC, the experiment of interlamellar pocket indicated that the structure of CL3 was homogeneous without degradation and vascularization in vivo at 12 weeks after surgery. Simultaneously, the results of transplantation of B-KPro showed complete epithelialization of CL3 within 1 week, and neovascularization of the cornea indicated rejection but could be controlled with immunosuppressants. At 3 months postoperatively, the lens of B-KPro remained transparent, and the structure of CL3 was compact and uniform, accompanied by the migration and proliferation of a large number of stromal cells without degradation, suggesting the CL3 could be a promising corneal substitute.

Application of chitosan nanoparticles in skin wound healing

The rising prevalence of impaired wound healing and the consequential healthcare burdens have gained increased attention over recent years. This has prompted research into the development of novel wound dressings with augmented wound healing functions. Nanoparticle (NP)-based delivery systems have become attractive candidates in constructing such wound dressings due to their various favourable attributes. The non-toxicity, biocompatibility and bioactivity of chitosan (CS)-based NPs make them ideal candidates for wound applications. This review focusses on the application of CS-based NP systems for use in wound treatment. An overview of the wound healing process was presented, followed by discussion on the properties and suitability of CS and its NPs in wound healing. The wound healing mechanisms exerted by CS-based NPs were then critically analysed and discussed in sections, namely haemostasis, infection prevention, inflammatory response, oxidative stress, angiogenesis, collagen deposition, and wound closure time. The results of the studies were thoroughly reviewed, and contradicting findings were identified and discussed. Based on the literature, the gap in research and future prospects in this research area were identified and highlighted. Current evidence shows that CS-based NPs possess superior wound healing effects either used on their own, or as drug delivery vehicles to encapsulate wound healing agents. It is concluded that great opportunities and potentials exist surrounding the use of CSNPs in wound healing.

Nanomedicine of Plant Origin for the Treatment of Metabolic Disorders

Metabolic disorders are major clinical challenges of health that are progressing globally. A concurrence of metabolic disorders such as obesity, insulin resistance, atherogenic dyslipidemia, and systematic hypertension leads to metabolic syndrome. Over the past years, the metabolic syndrome leads to a five- and two-fold rise in diabetes mellitus type II and cardiovascular diseases. Natural products specifically plant extracts have insulin-sensitizing, anti-inflammatory, and antioxidant properties and are also considered as an alternative option due to few adverse effects. Nanotechnology is one of the promising strategies, which improves the effectiveness of treatment and limits side effects. This review mainly focuses on plant extract-based nanosystems in the management of the metabolic syndrome. Numerous nano-drug delivery systems, i.e., liposomes, hydrogel nanocomposites, nanoemulsions, micelles, solid lipid, and core–shell nanoparticles, have been designed using plant extracts. It has been found that most of the nano-formulations successfully reduced oxidative stress, insulin resistance, chronic inflammation, and lipid profile in in vitro and in vivo studies as plant extracts interfere with the pathways of metabolic syndrome. Thus, these novel plant-based nanosystems could act as a promising candidate for clinical applications.

Therapeutic Applications of Curcumin in Diabetes: A Review and Perspective

Diabetes is a metabolic disease with multifactorial causes which requires lifelong drug therapy as well as lifestyle changes. There is now growing scientific evidence to support the effectiveness of the use of herbal supplements in the prevention and control of diabetes. Curcumin is one of the most studied bioactive components of traditional medicine, but its physicochemical characteristics are represented by low solubility, poor absorption, and low efficacy. Nanotechnology-based pharmaceutical formulations can help overcome the problems of reduced bioavailability of curcumin and increase its antidiabetic effects. The objectives of this review were to review the effects of nanocurcumin on DM and to search for databases such as PubMed/MEDLINE and ScienceDirect. The results showed that the antidiabetic activity of nanocurcumin is due to complex pharmacological mechanisms by reducing the characteristic hyperglycemia of DM. In light of these results, nanocurcumin may be considered as potential agent in the pharmacotherapeutic management of patients with diabetes.

Nanotechnology-based therapeutic applications: in vitro and in vivo clinical studies for diabetic wound healing

Diabetic wounds often indicate chronic complications that are difficult to treat. Unfortunately, existing conventional treatment modalities often cause unpremeditated side effects, given the need to develop alternative therapeutic phenotypes that are safe or have minimal side effects and risks. Nanotechnology-based platforms, including nanotherapeutics, nanoparticles (NPs), nanofibers, nanohydrogels, and nanoscaffolds, have garnered attention for their groundbreaking potential to decipher the biological environment and offer personalized treatment methods for wound healing. These nanotechnology-based platforms can successfully overcome the impediments posed by drug toxicity, existing treatment modalities, and the physiology and complexity of the wound sites. Furthermore, studies have shown that they play an essential role in influencing angiogenesis, collagen production, and extracellular matrix (ECM) synthesis, which are integral in skin repair mechanisms. In this review, we emphasized the importance of various nanotechnology-based platforms for healing diabetic wounds and report on the innovative preclinical and clinical outcomes of different nanotechnology-based platforms. This review also outlined the limitations of existing conventional treatment modalities and summarized the physiology of acute and chronic diabetic wounds.

Biomimetic silibinin-loaded macrophage-derived exosomes induce dual inhibition of Aβ aggregation and astrocyte activation to alleviate cognitive impairment in a model of Alzheimer's disease

Alzheimer's disease (AD) is a common neurodegenerative disease of the central nervous system. Due to its complex pathogenesis and the difficulty of drugs to cross the blood brain barrier (BBB), no effective clinical drugs are currently available that prevent the development of the course of AD. Silibinin (Slb) is known to exert dual therapeutic effects on reducing amyloid-β (Aβ) aggregation and deactivating astrocytes to improve behaviour and cognitive performance in subjects with Alzheimer's disease (AD). However, the poor brain targeting ability and low bioavailability limit its wide application. We aimed to encapsulate Slb in macrophage-derived exosomes (Exo-Slb) to improve its brain targeting ability. After entering the brain, exosomal Slb selectively interacted with Aβ monomers to reduce its aggregation. At the same time, Exo-Slb was internalized in astrocytes to inhibit their activation and alleviate astrocyte inflammation-mediated neuronal damage. Finally, Exo-Slb potently ameliorated cognitive deficits in AD mice.

Nanosafety vs. nanotoxicology: adequate animal models for testing in vivo toxicity of nanoparticles

Nanotoxicological studies using existing models of normal cells and animals often encounter a paradox: retention of nanoparticles in intracellular compartments for a long time is not accompanied by any significant toxicological effects. Can we expect that the revealed changes will be not harmful after translation to practice, outside of a sterile laboratory and ideally healthy organisms? Age-associated and pathological processes can affect target organs, metabolism, and detoxification in the mononuclear phagocyte system organs and change biodistribution routes, thus making the use of nanomaterial not safe. The potential solution to this issue can be testing the toxic properties of nanoparticles in animal models with chronic diseases. However, current studies of nanotoxicity in animal models with a brain, cardiovascular system, liver, digestive tract, reproductive system, and skin diseases are unsystematic. Even though these studies demonstrate the emergence of new toxic effects that are not present in healthy animals. In this regard, we set the goal of this review as the formulation of the requirements for an animal model capable of assessing the potential toxicity of nanoparticles based on the nanosafety approach.

Lipid-Based Drug Delivery Systems in Regenerative Medicine

The most important goal of regenerative medicine is to repair, restore, and regenerate tissues and organs that have been damaged as a result of an injury, congenital defect or disease, as well as reversing the aging process of the body by utilizing its natural healing potential. Regenerative medicine utilizes products of cell therapy, as well as biomedical or tissue engineering, and is a huge field for development. In regenerative medicine, stem cells and growth factor are mainly used; thus, innovative drug delivery technologies are being studied for improved delivery. Drug delivery systems offer the protection of therapeutic proteins and peptides against proteolytic degradation where controlled delivery is achievable. Similarly, the delivery systems in combination with stem cells offer improvement of cell survival, differentiation, and engraftment. The present review summarizes the significance of biomaterials in tissue engineering and the importance of colloidal drug delivery systems in providing cells with a local environment that enables them to proliferate and differentiate efficiently, resulting in successful tissue regeneration.

Efficacy of curcumin for wound repair in diabetic rats/mice: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Curcumin possesses multiple bioactivities that have beneficial effects on diabetic foot ulcers. Herein, we aimed to conduct a systematic preclinical review of 9 studies including a total of 262 animals, to assess the possible mechanisms of curcumin for wound healing in diabetic animals.

METHODS

Five databases were searched from inception to May 12, 2020; Rev-Man 5.3 software was applied for data analyses. Cochrane Collaboration's tool 10-item checklist was used to evaluate the methodological quality, and data revealed scores of risk of bias ranging from 2 to 5.

RESULTS

Meta-analysis indicated that curcumin had significant effects on wound healing rate and blood vessel density when compared with control (P < 0.05). The wound regeneration properties of curcumin for diabetic wounds are thought to mainly work through the possible mechanisms of antioxidation, enhanced cell proliferation, increased collagen formation, and angiogenesis. However, the anti-inflammatory effect on wounds in diabetic animals remains controversial.

CONCLUSIONS

The findings indicate that more randomized controlled trials should be pursued to obtain more reliable results regarding inflammatory response. Overall, curcumin might be a probable candidate for diabetic foot ulcers and may contribute to future clinical trials.

Systematic Development and Characterization of Novel, High Drug-Loaded, Photostable, Curcumin Solid Lipid Nanoparticle Hydrogel for Wound Healing

The study aims to develop high drug-loaded (about 15% lipid matrix) curcumin solid lipid nanoparticles (CSLNs) for wound healing. CSLNs prepared by hot, high-pressure homogenization, without using organic solvents, were optimized using the Taguchi design followed by the central composite design. The optimized CSLNs exhibited a high assay/drug content (0.6% w/w), solubility (6 × 105 times), and EE (75%) with a particle size < 200 nm (PDI-0.143). The CSLNs were safe (in vitro and in vivo), photostable, autoclavable, stable up to one year at 30 °C and under refrigeration and exhibited a controlled release (zero-order; 5 days). XRD, FTIR, and DSC confirmed solubilization and entrapment of the curcumin within the SLNs. TEM and FESEM revealed a smooth and spherical shape. The CSLNs showed a significant antimicrobial effect (MIC of 64 µg/mL for planktonic cells; 512 µg/mL for biofilm formation; and 2 mg/mL for mature biofilm) against Staphylococcus aureus 9144, while free curcumin dispersion did not exhibit any effect. This is the first report on the disruption of mature biofilms by curcumin solid lipid nanoparticles (CSLNs). The cell proliferation potential of CSLNs was also evaluated in vitro while the wound healing potential of CSLNs (incorporated in a hydrogel) was assessed in vivo. In (i) nitrogen mustard gas and (ii) a full-thickness excision wound model, CSLNs exhibited (a) significantly faster wound closure, (b) histologically and immunohistochemically better healing, (c) lower oxidative stress (LPO) and (d) inflammation (TNFα), and (e) increased angiogenesis (VEGF) and antioxidant enzymes, i.e., catalase and GSH levels. CSLNs thus offer a promising modern wound therapy especially for infected wounds, considering their effects in mature biofilm disruption.

Chitosan-based nanocarriers for encapsulation and delivery of curcumin: A review

To overcome the poor aqueous solubility and bioavailability of curcumin, emphasize its functional features, and broaden its applications in the food and pharmaceutical industries, many nanoscale systems have been widely applied for its encapsulation and delivery. Over many decades, chitosan as a natural biopolymer has been extensively studied due to its polycationic nature, biodegradability, biocompatibility, non-toxicity, and non-allergenic. Various chitosan-based nanocarriers with unique properties for curcumin delivery, including but not limited to, self-assembled nanoparticles, nanocomposites, nanoemulsions, nanotubes, and nanofibers, have been designed. This review focuses on the most-recently reported fabrication techniques of different types of chitosan-based nanocarriers. The functionalities of chitosan in each formulation which determine the physicochemical properties such as surface charge, morphology, encapsulation driving force, and release profile, were discussed in detail. Moreover, the current pharmaceutical applications of curcumin-loaded chitosan nanoparticles were elaborated. The role of chitosan in facilitating the delivery of curcumin and improving the therapeutic effects on many chronic diseases, including cancer, bacterial infection, wound healing, Alzheimer's diseases, inflammatory bowel disease, and hepatitis C virus, were illustrated. Particularly, the recently discovered mechanisms of action of curcumin-loaded chitosan nanoparticles against the abovementioned diseases were highlighted.

Therapeutic effects of EGF-modified curcumin/chitosan nano-spray on wound healing

Dermal injury, including trauma, surgical incisions, and burns, remain the most prevalent socio-economical health care issue in the clinic. Nanomedicine represents a reliable administration strategy that can promote the healing of skin lesions, but the lack of effective drug delivery methods can limit its effectiveness. In this study, we developed a novel nano-drug delivery system to treat skin defects through spraying. We prepared curcumin-loaded chitosan nanoparticles modified with epidermal growth factor (EGF) to develop an aqueous EGF-modified spray (EGF@CCN) for the treatment of dermal wounds. In vitro assays showed that the EGF@CCN displayed low cytotoxicity, and that curcumin was continuously and slowly released from the EGF@CCN. In vivo efficacy on wound healing was then evaluated using full-thickness dermal defect models in Wistar rats, showing that the EGF@CCN had significant advantages in promoting wound healing. On day 12 post-operation, skin defects in the rats of the EGF@CCN group were almost completely restored. These effects were related to the activity of curcumin and EGF on skin healing, and the high compatibility of the nano formulation. We therefore conclude that the prepared nano-scaled EGF@CCN spray represents a promising strategy for the treatment of dermal wounds.

Preparation and Evaluation of Collagen-Based Patches as Curcumin Carriers

Patients with psoriasis are dissatisfied with the standard pharmacological treatments, whether systemic or topical, with many of them showing interest in complementary and alternative medicine. Curcumin (Cur), a natural polyphenol derived from turmeric, has recently gained attention for skin-related diseases because of its proven anti-inflammatory action. However, topical treatment with Cur would be inadequate because of its hydrophobicity, instability, and low bioavailability. In addition, hyperkeratosis and lack of moisture in psoriatic skin result in low penetration that would prevent actives from permeating the stratum corneum. In this work, a polymer-based formulation of Cur for the topical treatment of psoriasis is reported. To improve the physicochemical stability of Cur, it was first encapsulated in chitosan nanoparticles. The Cur-loaded nanoparticles were incorporated in a hydrophilic, biocompatible collagen-based patch. The nanoparticle-containing porous collagen patches were then chemically cross-linked. Morphology, chemical interactions, swelling ratio, enzymatic hydrolysis, and Cur release from the patches were evaluated. All patches showed excellent swelling ratio, up to ~1500%, and after cross-linking, the pore size decreased, and their hydrolysis rates decelerated. The in vitro release of Cur was sustained with an initial burst release, reaching 55% after 24 h. Cur within the scaffolds imparted a proliferation inhibitory effect on psoriatic human keratinocytes in vitro.

Nanotechnology-driven advances in the treatment of diabetic wounds

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

Nanomedicine in Healing Chronic Wounds: Opportunities and Challenges

The poor healing associated with chronic wounds affects millions of people worldwide through high mortality rates and associated costs. Chronic wounds present three main problems: First, the absence of a suitable environment to facilitate cell migration, proliferation, and angiogenesis; second, bacterial infection; and third, unbalanced and prolonged inflammation. Unfortunately, current therapeutic approaches have not been able to overcome these main issues and, therefore, have limited clinical success. Over the past decade, incorporating the unique advantages of nanomedicine into wound healing approaches has yielded promising outcomes. Nanomedicine is capable of stimulating various cellular and molecular mechanisms involved in the wound microenvironment via antibacterial, anti-inflammatory, and angiogenetic effects, potentially reversing the wound microenvironment from nonhealing to healing. This review briefly discusses wound healing mechanisms and pathophysiology and then highlights recent findings regarding the opportunities and challenges of using nanomedicine in chronic wound management.

Silver nanoparticles: Advanced and promising technology in diabetic wound therapy

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

Modified acellular porcine corneal matrix in deep lamellar transplantation of rabbit cornea

This study presents to develop a modified acellular porcine corneal matrix (MAPCM) to maintain high transparency, stability and biocompatibility as a rabbit deep cornea replacement using 1-ethyl-3–(3-dimethylaminopropyl)-carbodiimide crosslinking and a mild decellularization technique. Scaffolds are translucent and remain higher amount of glycosaminoglycans after decellularization than acellular porcine corneal matrix (APCM). Enzymatic degradation kinetics and mechanical properties of scaffolds are regulated by 1-ethyl-3–(3-dimethylaminopropyl)-carbodiimide -crosslinking density. The porous structure and ultrastructure of collagenous lamellae are maintained, and the pore size of MAPCM crosslinked with 0.5% (w/v) 1-ethyl-3–(3-dimethylaminopropyl)-carbodiimide is 13.26 ± 1.65 µm, similar to that of normal porcine cornea. The transmittance of MAPCM gets 79.1 ± 0.45 to 92.7 ± 1.4% in the visible light range. Results from a CCK-8 assay indicate that MAPCM gets higher cell proliferation rate of rabbit corneal stroma cells than APCM. Since collagen fibres structural integrity and regularity of MAPCM are retained after crosslinking, the opacity and stability of MAPCM are better than those of APCM within 4 weeks of animal implantation. In addition, there is no indication of an immune response or neovascularization in or around the transplanted disc. These results reveal that MAPCM may be a more suitable scaffold for corneal substitute construction.