Curcumin loaded chitosan nanoparticles impregnated into collagen-alginate scaffolds for diabetic wound healing

Exploring the potential of an Aloe vera and honey extract loaded bi-layered nanofibrous scaffold of PCL-Col and PCL-SBMA mimicking the skin architecture for the treatment of diabetic wounds

Diabetic wounds are often chronic in nature, and issues like elevated blood sugar, bacterial infections, oxidative stress and persistent inflammation impede the healing process. To ensure the appropriate healing of wounds, scaffolds should promote complete tissue regeneration in wounds, both functionally and structurally. However, the available scaffolds lack the explicit architecture and functionality that could match those of native skin, thus failing to carry out the scar-free skin regeneration in diabetic wounds. This study deals with the synthesis of a bi-layered nanofibrous scaffold mimicking the native skin architecture in terms of porosity and hydrophobic-hydrophilic gradients. In addition, herbal extracts of Aloe vera and litchi honey were added in consecutive layers to manage the high blood glucose level, inflammation, and increased ROS level associated with diabetic wounds. In vitro studies confirmed that the prepared scaffold with herbal extracts showed enhanced proliferation of skin cells with good mechanical strength, degradability, anti-bacterial and anti-diabetic properties. The scaffold also demonstrated superior wound healing in vivo with quicker scar-free wound recovery and appropriate skin regeneration, compared to conventional treatment. Altogether, the synthesized herbal extract loaded bi-layered nanofibrous scaffold can be used as a regenerative template for hard-to-heal diabetic wounds, offering a new strategy for the management of chronic wounds.

Formulation and evaluation of n-acetyl cysteine loaded bi-polymeric physically crosslinked hydrogel with antibacterial and antioxidant activity for diabetic wound dressing

Diabetic wounds have become a serious global health concern, with a growing number of patients each year. Diabetic altered wound healing physiology, as well as resulting complications, make therapy difficult. Hence, diabetic wound healing necessitates a multidisciplinary strategy. This study focused on the formulation, statistical optimization, ex vivo, and in vitro evaluation of a diabetic wound healing by n-acetyl cysteine (NAC) loaded hydrogel. The objective of the study is to formulate n-acetyl loaded hydrogel with different ratio (1:1, 1:2, 1:3, 2:1) of sodium alginate and guar gum. The antibacterial and antifungal assessment against the viability of Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S.aureus) and Candida albicans (C. albicans) was conducted after determining the in vitro drug release profile. The results of the experiment demonstrated that the formulation F3 was an optimal formulation on triplicate measurement with a pH of 6.2 ± 0.168, and a density of 1.026 ± 0.21. In vitro cell line study exhibited F3 has potential role in cell adhesion and proliferation might be beneficial to tissue regeneration and wound healing. The results imply that F3 may be helpful for the quick healing of diabetic wounds by promoting angiogenesis and also by scavenging free oxygen radicals.

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

Mechanism and application of fibrous proteins in diabetic wound healing: a literature review

Diabetic wounds are more complex than normal chronic wounds because of factors such as hypoxia, reduced local angiogenesis, and prolonged inflammation phase. Fibrous proteins, including collagen, fibrin, laminin, fibronectin, elastin etc., possess excellent inherent properties that make them highly advantageous in the area of wound healing. Accumulating evidence suggests that they contribute to the healing process of diabetic wounds by facilitating the repair and remodel of extracellular matrix, stimulating the development of vascular and granulation tissue, and so on. However, there is currently a lack of a comprehensive review of the application of these proteins in diabetes wounds. An overview of fibrous protein characteristics and the alterations linked to diabetic wounds is given in this article's initial section. Next is a summary of the advanced applications of fibrous proteins in the last five years, including acellular dermal matrix, hydrogel, foam, scaffold, and electrospun nanofibrous membrane. These dressings have the ability to actively promote healing in addition to just covering wounds compared to traditional wound dressings like gauze or bandage. Research on fibrous proteins and their role in diabetic wound healing may result in novel therapeutic modalities that lower the incidence of diabetic wounds and thereby enhance the health of diabetic patients.

Eco-friendly and safe alternatives for the valorization of shrimp farming waste

The seafood industry generates waste, including shells, bones, intestines, and wastewater. The discards are nutrient-rich, containing varying concentrations of carotenoids, proteins, chitin, and other minerals. Thus, it is imperative to subject seafood waste, including shrimp waste (SW), to secondary processing and valorization for demineralization and deproteination to retrieve industrially essential compounds. Although several chemical processes are available for SW processing, most of them are inherently ecotoxic. Bioconversion of SW is cost-effective, ecofriendly, and safe. Microbial fermentation and the action of exogenous enzymes are among the significant SW bioconversion processes that transform seafood waste into valuable products. SW is a potential raw material for agrochemicals, microbial culture media, adsorbents, therapeutics, nutraceuticals, and bio-nanomaterials. This review comprehensively elucidates the valorization approaches of SW, addressing the drawbacks of chemically mediated methods for SW treatments. It is a broad overview of the applications associated with nutrient-rich SW, besides highlighting the role of major shrimp-producing countries in exploring SW to achieve safe, ecofriendly, and efficient bio-products.

In vitro and in vivo assessment of curcumin-quercetin loaded multi-layered 3D-nanofibroporous matrix prepared by solution blow-spinning for full-thickness burn wound healing

Burn wounds (BWs) cause impairment of native skin tissue and may cause significant microbial infections that demand immediate care. Curcumin (Cur) and quercetin (Que) exhibit antimicrobial, hemocompatibility, ROS-scavenging, and anti-inflammatory properties. However, its instability, water insolubility, and low biological fluid absorption render it challenging to sustain local Cur and Que doses at the wound site. Therefore, to combat these limitations, we employed blow-spinning and freeze-drying to develop a multi-layered, Cur/Que-loaded gelatin/chitosan/PCL (GCP-Q/C) nanofibroporous (NFP) matrix. Morphological analysis of the NFP-matrix using SEM revealed a well-formed multi-layered structure. The FTIR and XRD plots demonstrated dual-bioactive incorporation and scaffold polymer interaction. Additionally, the GCP-Q/C matrix displayed high porosity (82.7 ± 2.07 %), adequate pore size (∼121 μm), enhanced water-uptake ability (∼675 % within 24 h), and satisfactory biodegradation. The scaffolds with bioactives had a long-term release, increased antioxidant activity, and were more effective against gram-positive (S. aureus) and gram-negative (E. coli) bacteria than the unloaded scaffolds. The in vitro findings of GCP-Q/C scaffolds showed promoted L929 cell growth and hemocompatibility. Additionally, an in vivo full-thickness BW investigation found that an implanted GCP-Q/C matrix stimulates rapid recuperation and tissue regeneration. In accordance with the findings, the Gel/Ch/PCL-Que/Cur NFP-matrix could represent an effective wound-healing dressing for BWs.

Chitosan-2D Nanomaterial-Based Scaffolds for Biomedical Applications

Chitosan (CS) and two-dimensional nanomaterial (2D nanomaterials)-based scaffolds have received widespread attention in recent times in biomedical applications due to their excellent synergistic potential. CS has garnered much attention as a biomedical scaffold material either alone or in combination with some other material due to its favorable physiochemical properties. The emerging 2D nanomaterials, such as black phosphorus (BP), molybdenum disulfide (MoS2), etc., have taken huge steps towards varying biomedical applications. However, the implementation of a CS-2D nanomaterial-based scaffold for clinical applications remains challenging for different reasons such as toxicity, stability, etc. Here, we reviewed different types of CS scaffold materials and discussed their advantages in biomedical applications. In addition, a different CS nanostructure, instead of a scaffold, has been described. After that, the importance of 2D nanomaterials has been elaborated on in terms of physiochemical properties. In the next section, the biomedical applications of CS with different 2D nanomaterial scaffolds have been highlighted. Finally, we highlighted the existing challenges and future perspectives of using CS-2D nanomaterial scaffolds for biomedical applications. We hope that this review will encourage a more synergistic biomedical application of the CS-2D nanomaterial scaffolds and their utilization clinical applications.

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.

Advancements in 3D-printable polysaccharides, proteins, and synthetic polymers for wound dressing and skin scaffolding - A review

This review investigates the most recent advances in personalized 3D-printed wound dressings and skin scaffolding. Skin is the largest and most vulnerable organ in the human body. The human body has natural mechanisms to restore damaged skin through several overlapping stages. However, the natural wound healing process can be rendered insufficient due to severe wounds or disturbances in the healing process. Wound dressings are crucial in providing a protective barrier against the external environment, accelerating healing. Although used for many years, conventional wound dressings are neither tailored to individual circumstances nor specific to wound conditions. To address the shortcomings of conventional dressings, skin scaffolding can be used for skin regeneration and wound healing. This review thoroughly investigates polysaccharides (e.g., chitosan, Hyaluronic acid (HA)), proteins (e.g., collagen, silk), synthetic polymers (e.g., Polycaprolactone (PCL), Poly lactide-co-glycolic acid (PLGA), Polylactic acid (PLA)), as well as nanocomposites (e.g., silver nano particles and clay materials) for wound healing applications and successfully 3D printed wound dressings. It discusses the importance of combining various biomaterials to enhance their beneficial characteristics and mitigate their drawbacks. Different 3D printing fabrication techniques used in developing personalized wound dressings are reviewed, highlighting the advantages and limitations of each method. This paper emphasizes the exceptional versatility of 3D printing techniques in advancing wound healing treatments. Finally, the review provides recommendations and future directions for further research in wound dressings.

Curcumin-loaded mesoporous polydopamine nanoparticles modified by quaternized chitosan against bacterial infection through synergistic effect

Clinically, open wounds caused by accidental trauma and surgical lesion resection are easily infected by external bacteria, hindering wound healing. Antibacterial photodynamic therapy has become a promising treatment strategy for wound infection. In this study, a novel antibacterial nanocomposite material (QMC NPs) was synthesized by curcumin, quaternized chitosan and mesoporous polydopamine nanoparticles. The results showed that 150 μg/mL QMC NPs had good biocompatibility and exerted excellent antibacterial activity against Staphylococcus aureus and Escherichia coli after blue laser irradiation (450 nm, 1 W/cm2). In vivo, QMC NPs effectively treated bacterial infection and accelerated the healing of infected wounds in mice.

Design and in vitro evaluation of curcumin-loaded PLGA nanoparticle-embedded sodium alginate/gelatin 3D printed scaffolds for Alzheimer's disease

BACKGROUND

Targeted nanoparticles (NPs) are aimed at improving clinical outcomes by enhancing the diagnostic and therapeutic efficacy of drugs in the treatment of Alzheimer's disease (AD).

METHODS

Curcumin (CUR)-loaded poly-lactic-co-glycolic acid (PLGA) NPs (CNPs) were produced to demonstrate a prolonged release and successfully embedded into 3D printed sodium alginate (SA)/gelatin (GEL) scaffolds that can dissolve rapidly sublingually. Characterization and in vitro activity of the NPs and scaffolds were evaluated.

RESULTS

Based on the in vitro drug release studies, 99.6 % of the encapsulated CUR was released in a controlled manner within 18 days for the CNPs. In vitro cell culture studies showed that all samples exhibited cell viability above 84.2 % and no significant cytotoxic effect on SH-SY5Y cells. The samples were analyzed through 2 different pathways by PCR analysis. Real-time PCR results indicated that CNP and CNP-embedded SA/GEL scaffolds (CNPSGS) may show neuroprotective effects by modulating the Wnt/β-catenin pathway. The gene expression level of β-catenin slightly increased compared to the gene expression levels of other proteins and enzymes with these treatments. However, the PI3K/Akt/GSK-3β signaling pathway was regulated at the same time because of the crosstalk between these 2 pathways.

CONCLUSION

CNPSGS might be an effective therapeutic alternative for AD treatment.

Influences of Polyphenols on the Properties of Crosslinked Acellular Fish Swim Bladders: Experiments and Molecular Dynamic Simulations

Acellular fish swim bladders (AFSBs) are a promising biomaterial in tissue engineering, however, they may suffer from rapid degradation due to enzyme invasion. In this work, natural polyphenols, including epigallocatechin gallate (EGCG), proanthocyanidin (PC), tannic acid (TA) and protocatechuic acid (PCA), were utilized to improve the properties of AFSBs through crosslinking modifications. Fourier transform infrared (FTIR) results indicate that the triple helix of the collagen in AFSBs is well preserved after crosslinking. The differential scanning calorimetry (DSC), water contact angle (WCA) and in vitro degradation tests indicate that the polyphenol-crosslinked AFSBs exhibit improved thermal stability, enzymatic stability, hydrophilicity and mechanical properties. Among them, EGCG with multiple phenolic hydroxyl groups and low potential resistance is more favorable for the improvement of the mechanical properties and enzymatic stability of AFSBs, as well as their biocompatibility and integrity with the collagen triple helix. Moreover, the crosslinking mechanism was demonstrated to be due to the hydrogen bonds between polyphenols and AFSBs, and was affected by the molecular size, molecular weight and the hydroxyl groups activity of polyphenol molecules, as clarified by molecular dynamic (MD) simulations. The approach presented in this work paves a path for improving the properties of collagen materials.

3D Printing of Alginate/Chitosan-Based Scaffold Empowered by Tyrosol-Loaded Niosome for Wound Healing Applications: In Vitro and In Vivo Performances

This study introduces a tyrosol-loaded niosome integrated into a chitosan-alginate scaffold (Nio-Tyro@CS-AL), employing advanced electrospinning and 3D printing techniques for wound healing applications. The niosomes, measuring 185.40 ± 6.40 nm with a polydispersity index of 0.168 ± 0.012, encapsulated tyrosol with an efficiency of 77.54 ± 1.25%. The scaffold's microsized porous structure (600-900 μm) enhances water absorption, promoting cell adhesion, migration, and proliferation. Mechanical property assessments revealed the scaffold's enhanced resilience, with niosomes increasing the compressive strength, modulus, and strain to failure, indicative of its suitability for wound healing. Controlled tyrosol release was demonstrated in vitro, essential for therapeutic efficacy. The scaffold exhibited significant antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, with substantial biofilm inhibition and downregulation of bacterial genes (ndvb and icab). A wound healing assay highlighted a notable increase in MMP-2 and MMP-9 mRNA expression and the wound closure area (69.35 ± 2.21%) in HFF cells treated with Nio-Tyro@CS-AL. In vivo studies in mice confirmed the scaffold's biocompatibility, showing no significant inflammatory response, hypertrophic scarring, or foreign body reaction. Histological evaluations revealed increased fibroblast and macrophage activity, enhanced re-epithelialization, and angiogenesis in wounds treated with Nio-Tyro@CS-AL, indicating effective tissue integration and repair. Overall, the Nio-Tyro@CS-AL scaffold presents a significant advancement in wound-healing materials, combining antibacterial properties with enhanced tissue regeneration, and holds promising potential for clinical applications in wound management.

Understanding fenpropathrin-induced pulmonary toxicity: What apoptosis, inflammation, and pyreptosis reveal analyzing cross-links at the molecular, immunohistochemical, and immunofluorescent levels

Fenpropathrin (FN), a pyrethroid has been linked to potential pulmonary toxic effects to humans via incident direct or indirect ingestion. Thus, we aimed to the investigate the underlying mechanisms of lung toxicity upon exposure to FN in the rat model, besides studying whether curcumin (CCM) and curcumin-loaded chitosan nanoformulation (CCM-Chs) can mitigate FN-induced lung damage. Six distinct groups, namely, control, CCM, CCM-Chs, FN, and CCM + FN, CCM-Chs + FN were assigned separately. The inflammatory, apoptotic, and oxidative stress states, histological, immunohistochemical, and immunofluorescence examination of different markers within the pulmonary tissue were applied. The results revealed that the FN-induced tissue damage might be caused by the oxidative stress induction and depressed antioxidant glutathione system in the lungs of rats. Furthermore, FN upregulated the expression of genes related to inflammation, and pyroptosis, and elevated the immunoreactivity of Caspase-3, tumor necrosis factor-α, vimentin, and 4-Hydroxynonenal in pulmonary tissues of FN-exposed rats compared to the control. CCM and CCM-Chs mitigated the FN-induced disturbances, while remarkably, CCM-Chs showed better potency than CCM in mitigating the FN-induced toxicity. In conclusion, this study shows the prominent preventive ability of CCM-Chs more than CCM in combatting the pulmonary toxicity induced by FN. This may be beneficial in developing therapeutic and preventive strategies against FN-induced pulmonary toxicity.

Collagen-Based Scaffolds for Chronic Skin Wound Treatment

Chronic wounds, commonly known as ulcers, represent a significant challenge to public health, impacting millions of individuals every year and imposing a significant financial burden on the global health system. Chronic wounds result from the interruption of the natural wound-healing process due to internal and/or external factors, resulting in slow or nonexistent recovery. Conventional medical approaches are often inadequate to deal with chronic wounds, necessitating the exploration of new methods to facilitate rapid and effective healing. In recent years, regenerative medicine and tissue engineering have emerged as promising avenues to encourage tissue regeneration. These approaches aim to achieve anatomical and functional restoration of the affected area through polymeric components, such as scaffolds or hydrogels. This review explores collagen-based biomaterials as potential therapeutic interventions for skin chronic wounds, specifically focusing on infective and diabetic ulcers. Hence, the different approaches described are classified on an action-mechanism basis. Understanding the issues preventing chronic wound healing and identifying effective therapeutic alternatives could indicate the best way to optimize therapeutic units and to promote more direct and efficient healing.

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.

Creation of Chitosan-Based Nanocapsule-in-Nanofiber Structures for Hydrophobic/Hydrophilic Drug Co-Delivery and Their Dressing Applications in Diabetic Wounds

Nanofiber meshes (NFMs) loaded with therapeutic agents are very often employed to treat hard-to-heal wounds such as diabetic wounds. However, most of the NFMs have limited capability to load multiple or hydrophilicity distinctive-therapeutic agents. The therapy strategy is therefore significantly hampered. To tackle the innate drawback associated with the drug loading versatility, a chitosan-based nanocapsule-in-nanofiber (NC-in-NF) structural NFM system is developed for simultaneous loading of hydrophobic and hydrophilic drugs. Oleic acid-modified chitosan is first converted into NCs by the developed mini-emulsion interfacial cross-linking procedure, followed by loading a hydrophobic anti-inflammatory agent Curcumin (Cur) into the NCs. Sequentially, the Cur-loaded NCs are successfully introduced into reductant-responsive maleoyl functional chitosan/polyvinyl alcohol NFMs containing a hydrophilic antibiotic Tetracycline hydrochloride. Having a co-loading capability for hydrophilicity distinctive agents, biocompatibility, and a controlled release property, the resulting NFMs have demonstrated the efficacy on promoting wound healing either in normal or diabetic rats.

Thermo-Responsive Hydrogels Encapsulating Targeted Core-Shell Nanoparticles as Injectable Drug Delivery Systems

As therapeutic agents that allow for minimally invasive administration, injectable biomaterials stand out as effective tools with tunable properties. Furthermore, hydrogels with responsive features present potential platforms for delivering therapeutics to desired sites in the body. Herein, temperature-responsive hydrogel scaffolds with embedded targeted nanoparticles were utilized to achieve controlled drug delivery via local drug administration. Poly(N-isopropylacrylamide) (pNIPAM) hydrogels, prepared with an ethylene-glycol-based cross-linker, demonstrated thermo-sensitive gelation ability upon injection into environments at body temperature. This hydrogel network was engineered to provide a slow and controlled drug release profile by being incorporated with curcumin-loaded nanoparticles bearing high encapsulation efficiency. A core (alginate)-shell (chitosan) nanoparticle design was preferred to ensure the stability of the drug molecules encapsulated in the core and to provide slower drug release. Nanoparticle-embedded hydrogels were shown to release curcumin at least four times slower compared to the free nanoparticle itself and to possess high water uptake capacity and more mechanically stable viscoelastic behavior. Moreover, this therapy has the potential to specifically address tumor tissues over-expressing folate receptors like ovaries, as the nanoparticles target the receptors by folic acid conjugation to the periphery. Together with its temperature-driven injectability, it can be concluded that this hydrogel scaffold with drug-loaded and embedded folate-targeting nanoparticles would provide effective therapy for tumor tissues accessible via minimally invasive routes and be beneficial for post-operative drug administration after tumor resection.

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.

Bio-based polymers containing traditional medicinal fillers for wound healing applications - An evaluation of neoteric development and future perspectives

In recent years, health-care providers have seen more patients with difficult-to-treat wounds and burns. The biopolymer-based wound dressing protects the wounded area while assisting in the recovery of dermal and epithelial tissues throughout the healing process. The overall number of patients with chronic lesions has been expanding due to developing society, over weight, and cardiovascular illness. For the treatment of chronic wounds, there is an increasing demand for the development of ideal wound dressing materials with excellent properties such as antibacterial activity, biocompatibility, free radical scavenging capacity, non-adherent property, hydrophilicity, and so on. Nevertheless, owing to the above mention properties, natural polymers are being used for several key functions of biomedicine like narcotic distribution systems, tissue manufacturing, bandages, and so on. Accordingly, the significance of these bio-based polymers interfered with healing functions that lead to informing and inspiring youth and scientist researchers worldwide to grab with these far-reaching areas of medicine and biology. The review highlights the physiochemical properties of natural polymers, the biological evaluation of various materials as wound dressings, their synthesis and mechanical properties, clinical status, challenges, and future perspectives.

A novel hydrogel containing 4-methylcatechol for skin regeneration: in vitro and in vivo study

Skin damages are usual physical injuries and different studies have been done to improve wound healing. Hydrogel due to its properties like a moist environment and cooling wound site is a good option for wound treatment. In this study, we evaluated the consequence of using alginate/chitosan hydrogel contained various dosages of 4-Methylcatechol (0, 0.1, 1% (W/W)) on wound healing. After hydrogel fabrication, different tests like SEM, swelling, release, weight loss, and hemo- and cytocompatibility were done to characterize fabricated hydrogels. Finally, the rat model was used to assess Alginate/Chitosan hydrogel's therapeutic function containing 0.1 and 1% of 4-Methylcatechol. The pore size of hydrogel was between 24.5 ± 9 and 62.1 ± 11.63 µm and about 90% of hydrogel was lost after 14 days in the weight loss test. Blood compatibility and MTT assay showed that hydrogels were nontoxic and improved cell proliferation. In vivo test showed that Alginate/Chitosan/0.1%4-Methylcatechol improved wound healing and the results were significantly better than the gauze-treated wound. Our results showed dose depending effect of 4-Methylcatechol on wound healing. This study shows the treatment effect of 4-Methylcatechol on wound healing and the possibility of using it for treating skin injuries.

Two-Stage Supramolecular Self-Assembly-Directed Collagen-Peptide-Decorated Liposomal Complexes of Curcumin Microspheres with Enhanced Solubility and Bioavailability

Green formulations of phytonutrients with enhanced solubility and bioavailability are of great significance in nutrition therapy. In the present contribution, we hypothesized that the collagen peptides could be a safe, natural, food-grade, and cost-effective functional agent for the surface decoration and stabilization of liposomes in powder form and hence a "green" solution for the oral delivery of phytonutrients. The present study reports a two-stage supramolecular self-assembly-directed process for the preparation of collagen peptide-decorated liposomal complexes of curcumin (CCL) [10% (w/w)] as microspheres (125 ± 25 μm) with improved solubility (1.46 × 10⁵-fold) and sustained-release properties under gastrointestinal pH conditions. The molecular self-assembly of collagen peptides around the lipid bilayers and the various noncovalent interactions and conformational changes leading to the supramolecular assembly to act as a matrix for the encapsulation of lipid vesicles of curcumin were clear from the spectroscopic studies (UV-vis, fluorescence, FTIR, and circular dichroism). Further investigation of pharmacokinetics following a randomized double-blinded controlled trial on healthy volunteers (n = 15) demonstrated that the oral administration of 2.5 g of CCL sachet (250 mg of curcumin) enhanced the plasma concentration (C_max: 118 vs. 4.3 ng/mL), the elimination half-life (4.2 vs. 0.7 h), and bioavailability as per the area under the curve over 12 h [AUC_0-12h (CCL) = 506·8 vs. AUC_0-12h (C95) = 9.47 (53-fold)], when the plasma concentration of curcumin was estimated with triple quadruple tandem mass spectrometry (UPLC-ESI-MS/MS).

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.

Eco-friendly chitosan-based nanostructures in diabetes mellitus therapy: Promising bioplatforms with versatile therapeutic perspectives

Nature-derived polymers, or biopolymers, are among the most employed materials for the development of nanocarriers. Chitosan (CS) is derived from the acetylation of chitin, and this biopolymer displays features such as biocompatibility, biodegradability, low toxicity, and ease of modification. CS-based nano-scale delivery systems have been demonstrated to be promising carriers for drug and gene delivery, and they can provide site-specific delivery of cargo. Owing to the high biocompatibility of CS-based nanocarriers, they can be used in the future in clinical trials. On the other hand, diabetes mellitus (DM) is a chronic disease that can develop due to a lack of insulin secretion or insulin sensitivity. Recently, CS-based nanocarriers have been extensively applied for DM therapy. Oral delivery of insulin is the most common use of CS nanoparticles in DM therapy, and they improve the pharmacological bioavailability of insulin. Moreover, CS-based nanostructures with mucoadhesive features can improve oral bioavailability of insulin. CS-based hydrogels have been developed for the sustained release of drugs and the treatment of DM complications such as wound healing. Furthermore, CS-based nanoparticles can mediate delivery of phytochemicals and other therapeutic agents in DM therapy, and they are promising compounds for the treatment of DM complications, including nephropathy, neuropathy, and cardiovascular diseases, among others. The surface modification of nanostructures with CS can improve their properties in terms of drug delivery and release, biocompatibility, and others, causing high attention to these nanocarriers in DM therapy.

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.

A bio-polymeric scaffold incorporated with p-Coumaric acid enhances diabetic wound healing by modulating MMP-9 and TGF-β3 expression

Diabetic wounds lead to severe health complications as the tissue regeneration process fails predominantly due to prolonged inflammation, reactive oxygen species generation, and imbalance in collagen turnover. Modern wound dressings that can aid in wound management thus improving the public healthcare system, is the present need. This study aims to fabricate an effective wound dressing using plant polyphenol to treat chronic wounds as polyphenols possess excellent wound-healing ability. The collagen scaffold enriched with the polyphenol, p-Coumaric acid, was fabricated by freeze-drying method (Col-OxP3-Ca) and examined for its wound-healing ability by in vitro and in vivo analyses. Col-OxP3-Ca scaffold exhibited 85% antioxidant activity, biocompatibility in fibroblast cells, enhanced cell proliferation and migration rate. The diabetic excision wound treated with Col-OxP3-Ca scaffold healed within 21 days and a well-developed epidermis, blood vessels, hair follicle formation, fewer inflammatory cells and collagen deposition was observed in histological analysis. The immunohistochemical results depicted the enhanced expression of TGF-β3 and lessened expression of the MMP-9 in Col-OxP3-Ca scaffold treatment group. p-Coumaric acid shortened the inflammatory stage, enhanced angiogenesis, tissue regeneration and balanced collagen turnover during healing. From this, we can accomplish that the Col-OxP3-Ca wound dressing could be an outstanding alternative to treat chronic wounds.

In vitro and in vivo effect of novel GA-CSNPs loaded col-fibrin nanocomposite scaffold on diabetic wound healing

A non-healing wound is a common problem associated with diabetes mellitus. Chronic inflammation, challenging re-epithelization, unusual growth factors, and impaired angiogenesis are the multifactorial events that contribute to impaired wounds. Hence, in the present work, an innovative GA-CSNPs nanocomposite scaffold has been fabricated by integrating Gallic acid (GA) loaded chitosan nanoparticles (GA-CSNPs) into a genipin crosslinked collagen-fibrin (Col-fibrin) scaffold as wound dressing material. The in vitro RT-PCR study carried out using NIH/3T3 mouse fibroblast cells showed that treatment with GA-CSNPs nanocomposite scaffold aids in an upsurge in the expression of Col-I, III, and VEGF, which further supports the synthesis of extracellular matrix, increases neovascularization and development of the established vascular system. In vivo wound contraction study results revealed that diabetic wounds treated with GA-CSNPs nanocomposite scaffold show a faster rate of wound closure (p < .001), histopathology results showed accelerated fibroblast cell migration, reduction of the inflammatory cells, enhanced collagen along with hexosamine synthesis. In addition, immunohistochemistry results showed increased vascularization, a significant decrease in macrophage recruitment, and reduced expression of MMP-9 compared to the Col-fibrin scaffold and Control groups. Overall data suggest that the fabricated GA-CSNPs nanocomposite porous 3-D scaffold can be a hopeful therapeutic choice for diabetic wound management.

Proline conjugated chitosan as wound healing material: In vitro studies on the influence of the scaffold on collagen production and wound healing

The present study reports the development of L-proline conjugated chitosan scaffold for wound healing application. Proline plays a beneficial role in collagen synthesis, and as a biochemical, it has the potential to modulate wound healing. In this regard, amino acid L-proline was conjugated onto chitosan, and the scaffolds were synthesised. FTIR and NMR analysis confirmed amino acid conjugation. The prepared scaffold was characterized by studies such as swelling, dissolution, tensile strength, porosity, water-vapor transmission rate and in-vitro healing properties. Cell viability assay showed that the scaffold has no cytotoxicity against the L929 and HaCaT cells. The in-vitro wound healing potential of the scaffold by scratch wound assay on the L929 cell line showed 53.35 ± 2.3 %, 72.96 ± 2.2 %, and 50.89 ± 0.3 % wound closure for CS-P 200, CS-P 400 and CS-P 600, respectively when compared to native CS scaffold (38.86 ± 1.6 %). A similar observation was found with HaCaT cells too. The studies showed that the modified scaffold promotes collagen deposition from fibroblast cells. These findings suggest that scaffold cues remodel the wound microenvironment for a better wound-healing state, and the L-proline conjugated scaffold may have considerable potential as a wound dressing to improve wound healing.

A review on polysaccharides mediated electrospun nanofibers for diabetic wound healing: Their current status with regulatory perspective

The current treatment strategies for diabetic wound care provide only moderate degree of effectiveness; hence new and improved therapeutic techniques are in great demand. Diabetic wound healing is a complex physiological process that involves synchronisation of various biological events such as haemostasis, inflammation, and remodelling. Nanomaterials like polymeric nanofibers (NFs) offer a promising approach for the treatment of diabetic wounds and have emerged as viable options for wound management. Electrospinning is a powerful and cost-effective method to fabricate versatile NFs with a wide array of raw materials for different biological applications. The electrospun NFs have unique advantages in the development of wound dressings due to their high specific surface area and porosity. The electrospun NFs possess a unique porous structure and biological function similar to the natural extracellular matrix (ECM), and are known to accelerate wound healing. Compared to traditional dressings, the electrospun NFs are more effective in healing wounds owing to their distinct characteristics, good surface functionalisation, better biocompatibility and biodegradability. This review provides a comprehensive overview of the electrospinning procedure and its operating principle, with special emphasis on the role of electrospun NFs in the treatment of diabetic wounds. This review discusses the present techniques applied in the fabrication of NF dressings, and highlights the future prospects of electrospun NFs in medicinal applications.

Zinc oxide loaded chitosan-elastin-sodium alginate nanocomposite gel using freeze gelation for enhanced adipose stem cell proliferation and antibacterial properties

Hydrogels have been the material of choice for regenerative medicine applications due to their biocompatibility that can facilitate cellular attachment and proliferation. The present study aimed at constructing a porous hydrogel composite scaffold (chitosan, sodium alginate and elastin) for the repair of chronic skin wounds. Chitosan-based hydrogel incorporating varying concentrations of zinc oxide nanoparticles i.e. ZnO-NPs (0, 0.001, 0.01, 0.1 and 1 % w/w) as the antimicrobial agent tested against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) exhibited good antibacterial activities. ZnO-NPs were characterized by UV visible spectroscopy, Scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Fabricated gels were characterized by SEM analysis, FTIR, XRD, swelling ratio, degradation behavior and controlled release kinetics of ZnO-NPs. In vitro cytocompatibility of the composite was investigated using human adipose stem cells (ADSCs) by MTT and lactate dehydrogenase (LDH) assay, further assessed by SEM analysis and PKH26 staining. The SEM and XRD analysis confirmed the successful loading of ZnO-NPs into these scaffolds. Fluorescence PKH26 stained images and SEM analysis of ADSCs seeded scaffolds revealed biocompatible nature. The findings suggested that the developed composite gels have potential clinically for tissue engineering and chronic wound treatment.

Curcumin-loaded alginate hydrogels for cancer therapy and wound healing applications: A review

Hydrogels have emerged as a versatile platform for a numerous biomedical application due to their ability to absorb a huge quantity of biofluids. In order to design hydrogels, natural polymers are an attractive option owing to their biocompatibility and biodegradability. Due to abundance in occurrence, cost effectiveness, and facile crosslinking approaches, alginate has been extensively investigated to fabricate hydrogel matrix. Management of cancer and chronic wounds have always been a challenge for pharmaceutical and healthcare sector. In both cases, curcumin have been shown significant improvement and effectiveness. However, the innate restraints like poor bioavailability, hydrophobicity, and rapid systemic clearance associated with curcumin have restricted its clinical translations. The current review explores the cascade of research around curcumin encapsulated alginate hydrogel matrix for wound healing and cancer therapy. The focus of the review is to emphasize the mechanistic effects of curcumin with its fate inside the cells. Further, the review discusses different approaches to designed curcumin loaded alginate hydrogels along with the parameters that regulates their release behavior. Finally, the review is concluded with emphasize on some key aspect on increasing the efficacy of these hydrogels along with novel strategies to further develop curcumin loaded alginate hydrogel matrix with multifacet applications.

Effect of PCL nanofiber mats coated with chitosan microcapsules containing cinnamon essential oil for wound healing

INTRODUCTION

Cinnamon is one of the most common spices that has been studied for its anti-inflammatory, antioxidant, and antibacterial properties in wound healing. The purpose of this study was to evaluate the effectiveness of polycaprolactone nanofiber mats coated with chitosan microcapsules loaded with cinnamon essential oil in wound healing.

MATERIAL AND METHODS

For this purpose, chitosan microcapsules containing cinnamon essential oil (µCS-CiZ) were prepared by ion gelation and PCL nanofibers by electrospinning. The size of the µCS-CiZ and the morphology of nanofibers were evaluated by DLS and FESEM methods. In order to evaluate wound healing, 48 rats in 4 groups of Control, µCS-CiZ, PCL, and PCL + µCS-CiZ and were examined on days 7, 14, and 21 in terms of macroscopy (wound closure rate) and histology (edema, inflammation, vascularity, fibrotic tissue, and re-epithelialization).

RESULTS

The particle size of the µCS-CiZ and the diameter of the nanofibers were estimated at about 6.33 ± 1.27 μm and 228 ± 33 nm, respectively. On day 21, both µCS-CiZ and PCL groups showed a significant decrease in wound size compared to the control group (P < 0.001). The PCL + µCS-CiZ group also showed a significant decrease compared to the µCS-CiZ (P < 0.05) and PCL groups (P < 0.05). Histological results showed further reduction of edema, inflammation, and vascularity in granulation tissue and appearance of moderate to marked fibrotic tissue in PCL + µCS-CiZ group compared with the other groups.

CONCLUSION

The results of the study showed that the combined use of PCL + µCS-CiZ indicates a synergistic effect on improving wound healing.

Human beta defensin-2 loaded PLGA nanoparticles impregnated in collagen-chitosan composite scaffold for the management of diabetic wounds

Diabetic wound (DW) is the most devastating complication resulting in significant mortality and morbidity in diabetic patients. The standard treatment of DW care fails to address the prerequisites of treating DW owing to its multifactorial pathophysiology. Henceforth, developing a single treatment strategy to handle all the loopholes may effectively manage DW. The objective of the current study was to formulate Human beta defensin-2 (HBD-2) loaded Poly (lactic-co-glycolic acid) (PLGA) nanoparticle impregnated in collagen/chitosan (COL-CS) composite scaffolds for the accelerated healing of DW. Upon investigation, the developed biodegradable crosslinked scaffold possesses low matrix degradation, optimum porosity, and sustained drug release than the non-crosslinked scaffold. In vitro studies revealed that the HBD-2 COL-CS scaffold was biocompatible and accelerated cell migration and angiogenesis. The HBD-2 COL-CS scaffold showed significant antimicrobial activity in S. aureus, E. coli, and P. aeruginosa. The in vivo studies revealed that the HBD-2 COL-CS treated group accelerated healing compared to those in COL-CS and control groups. The ELISA results indicated a significant decrease in MMP-9, TNF-α, MPO, NAG, and NO with an increase in IL-10 in HBD-2 COL-CS treated group. The accelerated healing in HBD-2 COL-CS treated group might be due to the synergistic effects of PLGA (collagen synthesis and deposition and positive angiogenic effect), HBD-2 (anti-inflammatory, antibacterial, positive angiogenic effect, cell proliferation, and migration), COL (established wound healer and stabilizer) and CS (antibacterial, controlled drug release).

Accelular nanofibrous bilayer scaffold intrapenetrated with polydopamine network and implemented into a full-thickness wound of a white-pig model affects inflammation and healing process

Treatment of complete loss of skin thickness requires expensive cellular materials and limited skin grafts used as temporary coverage. This paper presents an acellular bilayer scaffold modified with polydopamine (PDA), which is designed to mimic a missing dermis and a basement membrane (BM). The alternate dermis is made from freeze-dried collagen and chitosan (Coll/Chit) or collagen and a calcium salt of oxidized cellulose (Coll/CaOC). Alternate BM is made from electrospun gelatin (Gel), polycaprolactone (PCL), and CaOC. Morphological and mechanical analyzes have shown that PDA significantly improved the elasticity and strength of collagen microfibrils, which favorably affected swelling capacity and porosity. PDA significantly supported and maintained metabolic activity, proliferation, and viability of the murine fibroblast cell lines. The in vivo experiment carried out in a domestic Large white pig model resulted in the expression of pro-inflammatory cytokines in the first 1-2 weeks, giving the idea that PDA and/or CaOC trigger the early stages of inflammation. Otherwise, in later stages, PDA caused a reduction in inflammation with the expression of the anti-inflammatory molecule IL10 and the transforming growth factor β (TGFβ1), which could support the formation of fibroblasts. Similarities in treatment with native porcine skin suggested that the bilayer can be used as an implant for full-thickness skin wounds and thus eliminate the use of skin grafts.

Application of Collagen-Based Hydrogel in Skin Wound Healing

The repair of skin injury has always been a concern in the medical field. As a kind of biopolymer material with a special network structure and function, collagen-based hydrogel has been widely used in the field of skin injury repair. In this paper, the current research and application status of primal hydrogels in the field of skin repair in recent years are comprehensively reviewed. Starting from the structure and properties of collagen, the preparation, structural properties, and application of collagen-based hydrogels in skin injury repair are emphatically described. Meanwhile, the influences of collagen types, preparation methods, and crosslinking methods on the structural properties of hydrogels are emphatically discussed. The future and development of collagen-based hydrogels are prospected, which is expected to provide reference for the research and application of collagen-based hydrogels for skin repair in the future.

Polymeric Nanoparticles as Tunable Nanocarriers for Targeted Delivery of Drugs to Skin Tissues for Treatment of Topical Skin Diseases

The topical route is the most appropriate route for the targeted delivery of drugs to skin tissues for the treatment of local skin diseases; however, the stratum corneum (SC), the foremost layer of the skin, acts as a major barrier. Numerous passive and active drug delivery techniques have been exploited to overcome this barrier; however, these modalities are associated with several detrimental effects which restrict their clinical applicability. Alternatively, nanotechnology-aided interventions have been extensively investigated for the topical administration of a wide range of therapeutics. In this review, we have mainly focused on the biopharmaceutical significance of polymeric nanoparticles (PNPs) (made from natural polymers) for the treatment of various topical skin diseases such as psoriasis, atopic dermatitis (AD), skin infection, skin cancer, acute-to-chronic wounds, and acne. The encapsulation of drug(s) into the inner core or adsorption onto the shell of PNPs has shown a marked improvement in their physicochemical properties, avoiding premature degradation and controlling the release kinetics, permeation through the SC, and retention in the skin layers. Furthermore, functionalization techniques such as PEGylation, conjugation with targeting ligand, and pH/thermo-responsiveness have shown further success in optimizing the therapeutic efficacy of PNPs for the treatment of skin diseases. Despite enormous progress in the development of PNPs, their clinical translation is still lacking, which could be a potential future perspective for researchers working in this field.

Particles-based medicated wound dressings: a comprehensive review

Wound healing is a dynamic process that is controlled by many factors. The interest in developing wound dressings capable of providing the required environment for the proper wound healing process is ever expanding, and particles occupy a sizable share of the research area. This comprehensive review reports 10 years of research in terms of current advances, delivery system evaluation, outcomes and future directions. The review follows a clearly defined method of article search and screening. Retrieved papers are reviewed regarding the materials, formulation development, and in vitro/in vivo testing of particles-based wound dressings. The review summarized the current status of medicated wound dressing research, identifies gaps to be addressed, and represents a reference for researchers working on wound dressings.

Novel PLCL nanofibrous/keratin hydrogel bilayer wound dressing for skin wound repair

In this study, a novel poly(L-lactate-caprolactone) copolymer (PLCL) nanofibrous/keratin hydrogel bilayer wound dressing loaded with fibroblast growth factor (FGF-2) was prepared by the low-pressure filtration-assisted method. The ability of the keratin hydrogel in the bilayer dressing to mimic the dermis and that of the nanofibrous PLCL to mimic the epidermis were discussed. Keratin hydrogel exhibited good porosity and maximum water absorption of 874.09%. Compared with that of the dressing prepared by the coating method, the interface of the bilayer dressing manufactured by the low-pressure filtration-assisted method (filtration time: 20 min) was tightly bonded, and its bilayer dressing interface could not be easily peeled off. The elastic modulus of hydrogel was about 44 kPa, which was similar to the elastic modulus of the dermis (2-80 kPa). Additionally, PLCL nanofibers had certain toughness and flexibility suitable for simulating the epidermal structures. In vitro studies showed that the bilayer dressing was biocompatible and biodegradable. In vivo studies indicated that PLCL/keratin-FGF-2 bilayer dressing could promote re-epithelialization, collagen deposition, skin appendages (hair follicles) regeneration, microangiogenesis construction, and adipose-derived stem cells (ADSCs) recruitment. The introduction of FGF-2 resulted in a better repair effect. The bilayer dressing also solved the problems of poor interface adhesion of hydrogel/electrospinning nanofibers. This paper also explored the preliminary role and mechanism of bilayer dressing in promoting skin healing, showing that its potential applications as a biomedical wound dressing in the field of skin tissue engineering.

Controlled release of protein from gelatin/chitosan hydrogel containing platelet-rich fibrin encapsulated in chitosan nanoparticles for accelerated wound healing in an animal model

The physiological healing process is disrupted in many cases using the current wound healing procedures, resulting in delayed wound healing. Hydrogel wound dressings provide a moist environment to enhance granulation tissue and epithelium formation in the wound area. However, exudate accumulation, bacterial proliferation, and reduced levels of growth factors are difficulties of hydrogel dressings. Here, we loaded platelet-rich fibrin-chitosan (CH-PRF) nanoparticles into the gelatin-chitosan hydrogel (Gel-CH/CH-PRF) by solvent mixing method. Our goal was to evaluate the characteristics of hydrogel dressings, sustained release of proteins from the hydrogel dressing containing PRF, and reduction in the risk of infection by the bacteria in the wound area. The Gel-CH/CH-PRF hydrogel showed excellent swelling behavior, good porosity, proper specific surface area, high absorption of wound exudates, and proper vapor permeability rate (2023 g/m ².day), which provided requisite moisture without dehydration around the wound area. Thermal behavior and the protein release from the hydrogels were investigated using simultaneous thermal analysis and the Bradford test, respectively. Most importantly, an excellent ability to control the release of proteins from the hydrogel dressings was observed. The high antimicrobial activity of hydrogel was confirmed using Gram-positive and Gram-negative bacteria. Due to the presence of chitosan in the hydrogels, the lowest scavenging capacity-50 value (5.82 μgmL^-1) and the highest DPPH radical scavenging activity (83 %) at a concentration 25 μgmL^-1 for Gel-CH/CH-PRF hydrogel were observed. Also, the hydrogels revealed excellent cell viability and proliferation. The wound healing process was studied using an in vivo model of the full-thickness wound. The wound closure was significantly higher on Gel-CH/CH-PRF hydrogel compared to the control group, indicating the highest epidermis thickness, and enhancing the formation of new granulation tissue. Our findings demonstrated that Gel-CH/CH-PRF hydrogel can provide an ideal wound dressing for accelerated wound healing.

Herbal Products and Their Active Constituents for Diabetic Wound Healing-Preclinical and Clinical Studies: A Systematic Review

The purpose of this review is to provide verified data on the current knowledge acquired in preclinical and clinical studies regarding topically used herbal products and their active constituents (formulations and dressings) with diabetic wound healing activity. Moreover, herbal products and their active constituents used for diabetic wound infections, and various cellular and molecular mechanisms of their actions will also be described. The electronic databases were searched for articles published from 2012 to 2022. Publications with oral or systemic administration of herbal products in diabetic wound healing, published before 2012, available only as an abstract, or in languages other than English were excluded from the study. The 59 articles comparing topically used herbal products in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. Herbal products through different mechanisms of action, including antimicrobial, anti-inflammatory, antioxidant activity, stimulation of angiogenesis, production of cytokines and growth factors, keratinocytes, and fibroblast migration and proliferation may be considered as an important support during conventional therapy or even as a substitute for synthetic drugs used for diabetic wound treatment.

Growth Factor Loaded Thermo-Responsive Injectable Hydrogel for Enhancing Diabetic Wound Healing

Background: Diabetic wound (DW) is the most devastating complication resulting in significant mortality and morbidity in diabetic patients. The objective of the current study was to formulate Epidermal Growth Factor loaded Chitosan nanoparticle impregnated with thermos-responsive injectable hydrogel with protease inhibitor. EGF, shown in all stages of wound healing from inflammation to proliferation and remodelling, combined with Doxycycline, a well-known anti-inflammatory and anti-bacterial drug, could be a better strategy in diabetic wound healing. However, EGF's low stability makes it difficult to use. Methodology: The nanoparticles were prepared using the ionic gelation method. The prepared nanoparticles were evaluated for particle size, zeta potential, entrapment efficiency, and SEM studies. Further, the optimized nanoparticle batch was loaded into hydrogel with a protease inhibitor. The hydrogel was evaluated for morphology, protease degradation, in vitro drug release, anti-bacterial activity, cell migration, in vitro cell biocompatibility, and in vivo wound healing studies. Results and Conclusion: The particle size analysis of nanoparticles revealed the size (203 ± 1.236 nm), Zeta potential (+28.5 ± 1.0 mV), and entrapment efficiency of 83.430 ± 1.8%, respectively. The hydrogel showed good porous morphology, injectability, thermo-responsive, biocompatibility, and controlled drug release. In vitro anti-bacterial studies revealed the potential anti-bacterial activity of doxycycline against various microbes. In vivo data indicated that combining EGF and DOX considerably reduced inflammation time-dependent than single-agent treatment. Furthermore, histological studies corroborated these findings. After topical application of hydrogel, histopathology studies revealed significant collagen synthesis and a fully regenerated epithelial layer and advancement in all three stages (proliferation, remodelling, and maturation), which are required to improve the diabetic wound healing process by any dressing. These findings demonstrated that hydrogel promoted cutaneous wound healing in STZ-induced rats by suppressing inflammation at the wound site. Furthermore, histological studies corroborated these findings. After topical application of hydrogel, histopathology studies revealed significant collagen synthesis, a fully regenerated epithelial layer, and advancement in all three stages (proliferation, remodelling, and maturation), which are required to improve the diabetic wound healing process by any dressing. These findings demonstrated that hydrogel promoted cutaneous wound healing in STZ-induced rats by suppressing inflammation at the wound site.

Fabrication of Biodegradable and Biocompatible Functional Polymers for Anti-Infection and Augmenting Wound Repair

The problem of bacteria-induced infections threatens the lives of many patients. Meanwhile, the misuse of antibiotics has led to a significant increase in bacterial resistance. There are two main ways to alleviate the issue: one is to introduce antimicrobial agents to medical devices to get local drug releasing and alleviating systemic toxicity and resistance, and the other is to develop new antimicrobial methods to kill bacteria. New antimicrobial methods include cationic polymers, metal ions, hydrophobic structures to prevent bacterial adhesion, photothermal sterilization, new biocides, etc. Biodegradable biocompatible synthetic polymers have been widely used in the medical field. They are often used in tissue engineering scaffolds as well as wound dressings, where bacterial infections in these medical devices can be serious or even fatal. However, such materials usually do not have inherent antimicrobial properties. They can be used as carriers for drug delivery or compounded with other antimicrobial materials to achieve antimicrobial effects. This review focuses on the antimicrobial behavior, preparation methods, and biocompatibility testing of biodegradable biocompatible synthetic polymers. Degradable biocompatible natural polymers with antimicrobial properties are also briefly described. Finally, the medical applications of these polymeric materials are presented.

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.

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.

Fabrication of bio-engineered chitosan nanoformulations to inhibition of bacterial infection and to improve therapeutic potential of intestinal microflora, intestinal morphology, and immune response in infection induced rat model

Overdosage of antibiotics used to prevent bacterial infections in the human and animal gastrointestinal tract would result in disturbing of intestinal barrier, significant misbalancing effects of intestinal microflora and persuading bacterial resistance. The main objective of the present investigation is to design and develop novel combinations of organic curcumin (Cur) and antimicrobial peptide (Amp) loaded chitosan nanoformulations (Cur/Amp@CS NPs) to improve significant effects on antibacterial action, immune response, intestine morphology, and intentional microflora. The antibacterial efficiency of the prepared nanoformulations was evaluated using Escherichia coli (E. coli) induced bacterial infections in GUT of Rat models. Further, we studied the cytocompatibility, inflammatory responses, α-diversity, intestinal morphology, and immune responses of treated nanoformulations in rat GUT models. The results indicated that Cur/Amp@CS NPs are greatly beneficial for intestinal microflora and could be a prodigious alternative of antibiotics.

Collagen fabricated delivery systems for wound healing: A new roadmap

Collagen is a biopolymer found in the animal body. It is one of the most abundant proteins in the extracellular matrix that provides strength to the skin, joints, and bones in the human body. It is an important source of elasticity and strength in the extracellular matrix and contributes to the structural and physiological integrity of tissues. Collagen plays an important role in regulating the wound healing process. It helps in wound healing by attracting fibroblasts and encouraging new collagen formation in the wound bed. Therefore, it can be used as a supplementary aid for wound treatment to accelerate the healing process. A prominent benefit of incorporating collagen in wound dressings is its ability to enhance the healing process for critical wounds. Not only collagen but various collagen-containing systems are being prepared to boost its efficacy in wound healing. Different strategies like nanoscale reductions, biopolymers, and incorporating anti-inflammatory and antimicrobial drugs with collagen have been reported. This review article emphasizes the use of collagen for wound healing and various collagen fabricated delivery systems such as nanofibres, nanoparticles, hydrogels, films, and sponges that aid in the healing of wounds.

Smart biomaterials and their potential applications in tissue engineering

Smart biomaterials have been rapidly advancing ever since the concept of tissue engineering was proposed. Interacting with human cells, smart biomaterials can play a key role in novel tissue morphogenesis. Various aspects of biomaterials utilized in or being sought for the goal of encouraging bone regeneration, skin graft engineering, and nerve conduits are discussed in this review. Beginning with bone, this study summarizes all the available bioceramics and materials along with their properties used singly or in conjunction with each other to create scaffolds for bone tissue engineering. A quick overview of the skin-based nanocomposite biomaterials possessing antibacterial properties for wound healing is outlined along with skin regeneration therapies using infrared radiation, electrospinning, and piezoelectricity, which aid in wound healing. Furthermore, a brief overview of bioengineered artificial skin grafts made of various natural and synthetic polymers has been presented. Finally, by examining the interactions between natural and synthetic-based biomaterials and the biological environment, their strengths and drawbacks for constructing peripheral nerve conduits are highlighted. The description of the preclinical outcome of nerve regeneration in injury healed with various natural-based conduits receives special attention. The organic and synthetic worlds collide at the interface of nanomaterials and biological systems, producing a new scientific field including nanomaterial design for tissue engineering.