Skin Wound Healing Process and New Emerging Technologies for Skin Wound Care and Regeneration

Herbal micelles-loaded ROS-responsive hydrogel with immunomodulation and microenvironment reconstruction for diabetic wound healing

Persistent inflammation is a major cause of diabetic wounds that are difficult to heal. This is manifested in diabetic wounds with excessive reactive oxygen clusters (ROS), advanced glycation end products (AGE) and other inflammatory factors, and difficulty in polarizing macrophages toward inhibiting inflammation. Berberine is a natural plant molecule that inhibits inflammation; however, its low solubility limits its biological function through cytosis. In this study, we designed F127 micelles to encapsulate berberine with the aim of improving its solubility and bioavailability. Meanwhile, in order to achieve effective drug delivery at the wound site, we designed an injectable ferrocene-cyclodextrin self-assembled oxidation-reactive supramolecular hydrogel drug delivery system. Cellular experiments have shown that the hydrogel can reduce intracellular ROS and AGE production, attenuate cellular damage, promote macrophage polarization toward inhibition of inflammation, and reduce the secretion of inflammatory factors. In an animal model of diabetic mice, this hydrogel dressing reduces the level of inflammation in diabetic wounds, optimizes collagen deposition in diabetic wounds, and ultimately achieves high-quality diabetic wound healing. The work offers a straightforward and effective solution to the challenge of administering hydrophobic anti-inflammatory agents in the context of diabetic wound therapy.

Baicalin loaded monodispersed polycaprolactone (PCL) microspheres preparation by polyvinylidene fluoride (PVDF) membrane emulsification for wound healing in dermal fibroblasts

The development of injectable bio-stimulating polycaprolactone (PCL) microspheres for wound healing has strict requirement on size and morphology control, particularly favoring microspheres within the range between 20-50 µm. PCL microspheres with smaller sizes are phagocyted at rapid rate while larger microspheres could cause inflammation. Homogenization can be regarded as an irreversible process to generate microspheres of particular size range while it still remains as the most common approach for microspheres production. Membrane emulsification technology shows great potential in fine tailoring of microspheres while still holds promising ability for scale-up production. Membranes with uniform large pores and dual hydrophilicity might be capable of the production of large microspheres via emulsification with tailorable size distribution. The aim of this study is to verify the feasibility of PVDF membranes with large pores on the generation of PCL microspheres via the combined crystallization diffusion (CCD) approach. The effect of dope solution concentration and PVDF molecular weights on membrane morphologies and the corresponding microspheres characteristics were investigated. Results showed that concentration of 20 wt% produced microspheres at desirable size of 24.14 µm and the optimal span of 0.53. Microspheres with narrow distribution showed the highest drug loading efficiency of baicalin at 8.42 %. The baicalin loaded PCL microspheres presented gradual release of drug release over 33-day of in vitro testing and significantly improved cell growth rate of 111.67 % as compared to the ones prepared by homogenization approach. The wound healing ability was enhanced after the treatment of baicalin-loaded PCL microspheres as compared to empty loaded PCL microspheres.

Development of ROS-responsive collagen-based hemostatic sponges for the repair of MRSA-infected wounds

Uncontrolled bleeding and infections, particularly from drug-resistant bacteria like Methicillin-Resistant Staphylococcus aureus (MRSA), pose significant challenges in clinical wound management, delaying healing, increasing patient discomfort, and elevating healthcare costs. This study introduces a novel reactive oxygen species (ROS)-responsive collagen-based hemostatic sponge designed to enhance wound healing and minimize blood loss, especially in MRSA-infected wounds. By chemically modifying the carboxyl groups of collagen with amino-rich oligomers, the primary amino content was increased, enhancing drug loading capacity-particularly for vancomycin-while also improving the sponge's mechanical properties, hemostatic performance, and biological stability. The ROS-responsive covalent bonding of vancomycin facilitated controlled vancomycin release in response to ROS, offering superior antibacterial efficacy and specifically targeting MRSA more effectively than conventional non-ROS-responsive approaches. In MRSA-infected full-thickness skin repair models, the ROS-responsive vancomycin-loaded sponge significantly enhanced wound healing and skin regeneration compared to both the physical adsorption group and the non-ROS-responsive release group. These results underscore the potential of the ROS-responsive collagen composite as an advanced hemostatic material with enhanced antibacterial capabilities, providing rapid hemostasis and improved healing outcomes for complex or infected wounds.

Extracellular vesicles and bioactive peptides for regenerative medicine in cosmetology

As life quality improves and the life pressure increases, people's awareness of maintaining healthy skin and hair grows. However, the use of bioactive peptides in regenerative medical aesthetics is often constrained by the high molecular weight, which impedes skin penetration. In contrast, extracellular vesicles not only possess regenerative properties but also serve as effective carriers for bioactive peptides. Given their anti-inflammatory and bactericidal properties, capacity to promote angiogenesis, optimize collagen alignment, facilitate re-epithelialization and stimulate hair growth, extracellular vesicles become an emerging and promising solution for skin regeneration treatments. The combination of peptides and extracellular vesicles enhances therapeutic efficacy and improves the bioavailability of bioactive peptides. In this review, we summarize the functions of bioactive peptides and plant- and animal-derived extracellular vesicles in regenerative medicine with cosmetology, along with examples of their combined applications. Additionally, we provide an overview of peptides and extracellular vesicles currently available on the market and in clinical practice, discussing the challenges and solutions associated with their use.

Starch-Based scaffold produced by FDM 3D printing technique as Innovative and biosustainable wound dressing

Starch is a safe biopolymer, whose use for the production of scaffolds intended for deep wounds treatment is limited, due to its low mechanical and thermal properties. For this reason, until now, it has been used in low amounts and/or in combination with other biopolymers. The aim of the study was to produce thermoplastic filaments (TPS) with high starch content, useful for scaffolds production by Fusion Deposition Modelling 3D printing technique. TPS was obtained by hot melt extrusion from a mixture of starch (70 % w/w) and glycerol (30 % w/w) combined to cationic clay montmorillonite, citric acid and magnesium stearate to improve strength and processability. The prepared scaffold was characterized and compared to other two scaffolds, where the effect of the addition of polycaprolactone (PCL) or methylsulphonylmethane (MSM) (as thermostable model drug) to the blend was evaluated. The mechanical properties were investigated by Brillouin Light Scattering. In vitro studies highlighted that the scaffolds are: i) able to absorb simulated exudates (reaching a hydration of 35 % in 7 days); ii) safe on keratinocytes (viability > 70 %) stimulating their growth; iii) able to inhibit S. pyogenes growth.

Polyurethane/silk fibroin-based electrospun membranes for wound healing and skin substitute applications

The importance of electrospun membranes for biomedical applications has increased, especially when it comes to skin regeneration and wound healing. This review presents the production and applications of electrospun membranes based on polyurethane (PU) and silk fibroin (SF) and highlights their benefits as a skin substitute. This review also highlights the electrospinning technique used to prepare nanofibers for these biomedical applications. Silk, well-known for its excellent biocompatibility, biodegradability, structural properties, and low immunogenic response, is extensively investigated by addressing its molecular structure, composition, and medical uses. PU is a candidate for potential biomedical applications because of its strength, flexibility, biocompatibility, cell-adhesive properties, and high resistance to biodegradation. PU combined with silk offers a number of enhanced properties. The study offers a comprehensive overview of the advanced developments and applications of PU/SF composites, highlighting their significant potential in wound healing. These composite membranes present promising advancements in wound healing and skin regeneration by combining the unique properties of silk and PU, opening up the possibilities for innovative treatments.

Wound Tissue Regeneration by Microfluidic Generated Fibroblast Cell/CuO Nanosheet-Loaded Alginate Hydrogel on an Excisional Full-Thickness Rat Model

Chronic ulcers present numerous challenges in treatment such as prolonged inflammation, infections resistant to drugs, and the formation of scars. In this research, we developed a calcium ion (Ca2+) cross-linked alginate (Alg) hydrogel loaded with CuO nanosheet/fibroblast cells via a microfluidic system with substantial efficiency in accelerating healing and preventing infection. Initially, the soft lithography method was utilized to fabricate the microfluidic system, which was employed to produce alginate hydrogel incorporating nanosheets of copper oxide (CuO) and MEF cells. The properties of hydrogel and copper oxide nanosheets were analyzed by using FE-SEM, EDS/EDX, and elemental mapping to determine their physicochemical characteristics. The viability of mouse embryonic fibroblast cells (MEF) in alginate-CuO hydrogel was explored through cell viability assay, and the antibacterial properties were also studied using colony-forming assay. The healing abilities of the hydrogel were investigated using an excisional, full-thickness wound rat model. Our results revealed proper antimicrobial and angiogenic properties with slight cytotoxicity for CuO nanosheets at a concentration of 25 μg/mL. The alginate-CuO-cell-treated group exhibited a faster wound contraction and healing among all treatments. The results of the in vivo assay along with histology and gene expression indicate a synergistic cooperation between MEF and CuO, leading to enhanced re-epithelialization, angiogenesis, and matrix remodeling. In this research, a therapeutic hydrogel with qualities like microbicidal, angiogenic, immune system modulation, and promotion of ECM and epithelium regeneration, resulting in faster healing, was developed. Moreover, there was a synergic impact noticed between CuO nanosheets and MEF cells as well as improved formation of blood vessels and collagen accumulation. In conclusion, this biocompatible hydrogel offers a promising strategy for effective wound healing without the need for invasive procedures.

Self-Healing Polymeric Puerarin Hydrogel Dressing Promotes Diabetic Wound Healing Through Synergistic Immunomodulation and Tissue-Regenerative Remodeling

Chronic wound healing is a significant challenge in diabetes. Puerarin is an active compound extracted from the traditional Chinese medicine Pueraria lobata. Puerarin has been used in the treatment of diabetes and derives benefits from its antioxidant, anti-inflammatory, antibacterial, and pro-angiogenesis properties, but its efficacy is hampered by poor water solubility and bioavailability. In this study, we designed a polyvinyl alcohol (PVA)-borax-puerarin (BP) hydrogel system that self-assembled via boronic ester bonds. The BP hydrogel exhibited exceptional physical characteristics, including adaptability, injectability, plasticity, self-healing capabilities, and robust compressive strength, as well as good biocompatibility. In the chronic wound diabetic rats model, the BP hydrogel significantly accelerated wound healing, as evidenced by hematoxylin and eosin (HE) staining, as well as Masson and picrosirius red (PSR) staining. RNA-sequencing and multiple immunohistochemistry (mIHC) analyses revealed that the BP hydrogel exerts a therapeutic effect by modulating macrophage polarization, promoting angiogenesis, and regulating collagen remodeling. Our findings suggest that the BP hydrogel represents a promising wound dressing and holds great potential for clinical applications in acute and chronic wound management.

Recent advances in structural and functional design of electrospun nanofibers for wound healing

The global prevalence of acute and chronic wounds has surged, escalating healthcare burdens and necessitating advanced therapeutic strategies for effective wound management. Electrospun nanofibers have emerged as promising biomimetic platforms for tissue engineering and drug delivery, due to their structural resemblance to the native extracellular matrix (ECM), high porosity, and tunable surface-to-volume ratio. Recent advances in structural design have expanded their applications from conventional two-dimensional (2D) wound dressings to multifunctional three-dimensional (3D) architectures, enabling enhanced mechanical adaptability, bioactive molecule loading, and spatiotemporal control over wound microenvironments. These innovations leverage nanofibers' customizable topography and composition to recapitulate critical ECM cues, thereby fostering cell proliferation, angiogenesis, and immunomodulation during tissue regeneration. This review systematically evaluates cutting-edge strategies focusing on optimizing 2D arrangements and the structural design of multilayered and functionally patterned 3D electrospun nanofibers in wound healing applications. We further present the advantages and limitations of various nanofiber structures, along with the key challenges and future directions for advancing electrospun nanofibers specifically designed for enhanced wound healing.

Mechanism underlying the involvement of CXCR4/CXCL12 in diabetic wound healing and prospects for responsive hydrogel-loaded CXCR4 formulations

Diabetes mellitus is a prevalent chronic disease, often leading to complications, with chronic wounds being among the most challenging. Impairment of the CXCR4/CXCL12 signaling pathway, which plays a key role in cell mobilization, migration, and angiogenesis, significantly hampers the wound healing process in diabetic patients. Modulation of this pathway using CXCR4-targeted agents has shown promise in restoring wound repair capabilities. Additionally, the development of responsive hydrogels capable of adapting to external stimuli offers a powerful platform for drug delivery in chronic wound management. These hydrogels, when loaded with CXCR4 agonists or antagonists, enable controlled drug release and real-time therapeutic modulation. Integrating such hydrogels with existing wound healing strategies may provide an innovative and effective solution for overcoming the challenges associated with diabetic wound treatment.

Preclinical Assessment of Living Therapeutic Materials: State-of-Art and Challenges

Living Therapeutic Materials represent a promising technology to tackle therapeutic problems that classical materials cannot address. Despite the advancements on new functions of these devices, new applications, and new fabrication methods, the preclinical evaluation of Living Therapeutic Materials is still very limited and new challenges appear when incorporating the living devices in contact with the host. This is a critical bottleneck in the path to translation to the clinic. Therefore, we have compiled the literature on Living Therapeutic Materials, with a focus on microorganism-based living therapeutic materials, and summarized the investigations carried out to assess their biocompatibility, safety, and efficacy. We have split the investigations in three parts: in vitro, ex vivo, and in vivo assessments, where we describe common practices and remaining challenges.

Cellulose-Based Nanofibers Infused with Biotherapeutics for Enhanced Wound-Healing Applications

Nanofibers fabricated from various materials such as polymers, carbon, and semiconductors have been widely used for wound healing and tissue engineering applications due to their excellent nontoxic, biocompatible, and biodegradable properties. Nanofibers with a diameter in the nanometer range possess a larger surface area per unit mass permitting easier addition of surface functionalities and release of biotherapeutics incorporated compared with conventional polymeric microfibers. Henceforth, nanofibers are a choice for fabricating scaffolds for the management of wound healing. Nanofibrous scaffolds have emerged as a promising method for fabricating wound dressings since they mimic the fibrous dermal extracellular matrix milieu that offers structural support for wound healing and functional signals for guiding tissue regeneration. Cellulose-based nanofibers have gained significant attention among researchers in the fabrication of on-site biodegradable scaffolds fortified with biotherapeutics in the management of wound healing. Cellulose is a linear, stereoregular insoluble polymer built from repeated units of d-glucopyranose linked with 1,4-β glycoside bonds with a complex and multilevel supramolecular architecture. Cellulose is a choice and has been used by various researchers due to its solubility in many solvents and its capacity for self-assembly into nanofibers, facilitating the mimicry of the natural extracellular matrix fibrous architecture and promoting substantial water retention. It is also abundant and demonstrates low immunogenicity in humans due to its nonanimal origins. To this end, cellulose-based nanofibers have been studied for protein delivery, antibacterial activity, and biosensor applications, among others. Taken together, this review delves into an update on cellulose-based nanofibers fused with bioactive compounds that have not been explored considerably in the past few years.

Overcoming drug delivery challenges with lipid-based nanofibers for enhanced wound repair

Wound healing is a dynamic, multi-phase process that includes haemostasis, tissue regeneration, cellular proliferation, and matrix modification. Traditional wound care procedures frequently encounter complications such as delayed healing and infection, demanding new therapeutic approaches. In this context, nanomaterial-based devices provide considerable benefits due to their capacity to improve medication delivery and tissue healing. We suggest a lipid-based nanofiber formulation for wound treatment that overcomes the restricted skin penetration of hydrophilic niacin, a strong wound healing agent. Niacin-loaded nanofibers (NLNFs) were manufactured utilizing glyceryl monostearate (GMS) by a self-assembly process, which included high-pressure homogenization and probe sonication for optimum nanostructure creation. The NLNFs were physicochemically characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, scanning electron microscopy (SEM) and surface profilometry to determine their morphology and homogeneity, and a drop shape analyser was used to determine hydrophobicity. In vitro tests revealed prolonged drug release, great cytocompatibility, and strong antioxidant activity, indicating superior free radical scavenging capacity. Ex vivo tests, such as the Draize skin irritation test, skin permeation test, and drug retention assays, revealed low skin irritation, increased permeability, and efficient drug retention in skin layers. In vivo experiments showed rapid wound closure and positive histological results, which were backed by hemocompatibility tests such as hemolysis and whole blood clot analysis, validating the formulation's safety. ELISA results indicated that the NLNF-treated group had higher levels of critical wound-healing indicators than the controls. Overall, our findings suggest that NLNFs have tremendous potential as a unique and effective treatment alternative for controlling and improving wound healing processes.

Collagen-Based Wound Dressings: Innovations, Mechanisms, and Clinical Applications

Collagen-based wound dressings have developed as an essential component of contemporary wound care, utilizing collagen's inherent properties to promote healing. This review thoroughly analyzes collagen dressing advances, examining different formulations such as hydrogels, films, and foams that enhance wound care. The important processes by which collagen promotes healing (e.g., promoting angiogenesis, encouraging cell proliferation, and offering structural support) are discussed to clarify its function in tissue regeneration. The effectiveness and adaptability of collagen dressings are demonstrated via clinical applications investigated in acute and chronic wounds. Additionally, commercially accessible collagen-based skin healing treatments are discussed, demonstrating their practical use in healthcare settings. Despite the progress, the study discusses the obstacles and restrictions encountered in producing and adopting collagen-based dressings, such as the difficulties of manufacturing and financial concerns. Finally, the current landscape's insights indicate future research possibilities for collagen dressing optimization, bioactive agent integration, and overcoming existing constraints. This analysis highlights the potential of collagen-based innovations to improve wound treatment methods and patient care.

A Non-randomized, Open-label, Multicenter Study to Evaluate the Safety and Tolerability of 10% Aminolevulinic Acid Gel in the Expanded Field-directed Treatment of Actinic Keratosis on the Face and Scalp with Red Light Photodynamic Therapy

Objective

Dermatologists regularly encounter patients having expanded fields with numerous actinic keratosis (AK) lesions on the face and scalp. Field-directed red light photodynamic therapy (PDT) is a well-established treatment, yet published data on the safety of PDT on large areas is scarce. We aimed to evaluate the safety and tolerability of red light PDT in treating expanded AK fields on the face and scalp.

Methods

This was a non-randomized, open-label, multicenter study. After lesion preparation, 6g of 10% aminolevulinic acid (ALA) gel were applied to the treatment field (60 cm2) and incubated for three hours under a light-blocking, occlusive dressing before 10-minute illumination with a red light lamp (~635nm, 37 J/cm2). Safety and tolerability were assessed throughout the study.

Results

All participants (n=100) had adverse reactions. No previously unknown effects, serious adverse events, or deaths were reported. The most frequent application site reactions were pain/burning (96.0%), exfoliation (87.0%), and erythema (86.0%). Most treatment-emergent adverse events were of mild to moderate severity and lasted slightly longer compared to those experienced after treatment of smaller areas. The mean maximum pain during PDT was 7.4±2.1 on an 11-point numeric rating scale. A transient increase in blood pressure on the day that PDT was performed was not clinically significant.

Limitations

Although the allowed use of pain-reducing measures might have influenced evaluation of pain, it reflects how the procedure is managed in current practice.

Concklusion

PDT with 10% ALA gel and red light illumination on an expanded treatment field was generally well tolerated.

Innovating chitosan-based bioinks for dermal wound healing: Current progress and future prospects

The field of three-dimensional (3D) bio/printing, known as additive manufacturing (AM), heavily relies on bioinks possessing suitable mechanical properties and compatibility with living cells. Among the array of potential hydrogel precursor materials, chitosan (CS) has garnered significant attention due to its remarkable physicochemical and biological attributes. These attributes include biodegradability, nontoxicity, antimicrobial properties, wound healing promotion, and immune system activation, making CS a highly appealing hydrogel-based bioink candidate. This review explores the transformative potential of CS-based bioink for enhancing dermal wound healing therapies. We highlight CS's unique qualities that make it an optimal choice for bioink development. Advancements in 3D bio/printing technology for tissue engineering (TE) are discussed, followed by an examination of strategies for CS-based bioink formulation and their impacts on wound healing. To address the progress in translating advanced wound healing from lab to clinic, we highlight the current and ongoing research in CS-based bioink for 3D bio/printing in skin wound healing applications. Finally, we explore current evidence, commercialization prospects, emerging innovations like 4D printing, and the challenges and future directions in this promising field.

Synthesis and Characterization of Antibacterial Poly{2-[(methacryloyloxy)ethyl]trimethylammonium Chloride}/Chitosan Semi-Interpenetrating Networks for Papain Release

Annually, thousands of individuals suffer from skin injuries resulting from trauma, surgeries, or diabetes. Inadequate wound treatment can delay healing and increase the risk of severe infections. In this context, a promising synthetic polymer with potent antimicrobial properties, Poly{2-[(methacryloyloxy)ethyl]trimethylammonium chloride} (PMETAC), is synthesized and crosslinked with N,N'-Methylenebis(acrylamide) (BIS) in the presence of Chitosan (CH), a natural, biocompatible polysaccharide that promotes cell regeneration and provides additional beneficial properties. These semi-interpenetrating (semi-IPN) networks are chosen as a matrix for releasing papain, a proteolytic enzyme with healing and debridement properties. By integrating the properties of the materials, this study evaluates PMETAC-based hydrogels with different CH concentrations (5%, 10%, and 25%) to understand their physicochemical and biological performance, including antibacterial activity and cytocompatibility. By incorporating 25% CH led to a 19% increase in pore size and a 48% increase in maximum pore volume compared to the control PMETAC hydrogel. Additionally, all formulations demonstrate ≈100% reduction of E. coli and S. aureus, showcasing their remarkable antibacterial efficacy. The inclusion of CH also significantly improves fibroblast viability, with 25% CH formulation standing out as the most promising candidate for multifunctional dressings, highlighting their potential in the treatment of hard-to-heal wounds in regenerative medicine.

Peptide-Based Functional Amyloid Hydrogel Enhances Wound Healing in Normal and Diabetic Rat Models

The inability to heal on time is a key component of chronic wounds, which can result in economic, psychological, and physiological burdens. Hydrogels based on amyloid can imitate the extracellular matrix and function as scaffolds for healing wounds. In this direction, a wound dressing inspired by peptide-based amyloid hydrogel is fabricated here. The results demonstrate that the amyloid hydrogel improves the three essential components of skin tissue regeneration: cell migration, proliferation, and collagen remodeling, both in vitro and in vivo. Furthermore, the amyloid hydrogel accelerates wound healing and promotes wound closure within 9 and 15 d in normal and diabetic rats, respectively. Microscopic evaluation of the wound region demonstrates the ultimate stages of regeneration and skin reformation toward normal skin compared to the untreated wound. Hematoxylin and eosin-stained hydrogel-treated wound sites reveal faster dermal bridging, angiogenesis, and epidermal repair in both acute and chronic conditions. The hydrogel creates an environment that encourages the growth of dermal fibroblasts and the release of cytokines, decreasing inflammation with concomitant enhancement of collagen production at the site of injury. Thus, these findings suggest that amyloid-based hydrogel can be a promising candidate for application in acute and chronic wound healing.

Black raspberry seed oil - Chemical composition, antioxidant/antimicrobial activities and in vitro wound-healing potential

This study aimed to perform chemical characterization of black raspberry seed oil (Rubus occidentalis L., Rosaceae) from Serbia in terms of fatty acids and tocols composition, total carotenoid content, as well as to investigate its antioxidant/antimicrobial activities and in vitro wound-healing potential. GC/MS analysis revealed that linoleic (39.30 %), α-linolenic (30.49 %) and oleic (18.94 %) acid were dominant fatty acids. HPLC analysis highlighted γ-tocopherol as the prevailing tocopherol isomer (166.80 mg/100 g). Spectrophotometric method determined a total carotenoid content of 1.20 mg/100 g. Appreciable antiradical activity (DPPH - IC50 3.02 mg/mL; ABTS - IC50 1.33 mg/mL) and a high level of reducing ability (FRAP value of 393.74 μmol Fe2+/100 g) were observed. Significant antibacterial activity against Salmonella Typhimurium, Escherichia coli and Bacillus cereus, in addition to antifungal activity against strains from Aspergillus and Trichoderma genera, was demonstrated. By cell viability assay, no cytotoxicity (IC50 > 401 μg/mL) was established on human keratinocytes (HaCaT cells). The wound-healing activity, evaluated by scratch assay, was found to be 2.41-fold higher in HaCaT cells treated with 100 μg/mL of black raspberry seed oil (41.77 %) than in non-treated cells (17.34 %). Taken together, black raspberry seed oil holds promising health potential.

Biomimetic gradient hydrogel with fibroblast spheroids for full-thickness skin regeneration

Hydrogel-based scaffolds have been widely investigated for their use in tissue engineering to accelerate tissue regeneration. However, replicating the physiological microenvironments of tissues with appropriate biological cues remains challenging. Recent advances in gradient hydrogels have transformed tissue-engineering research by providing precise structures that mimic the extracellular matrix of natural tissues. Unlike conventional homogeneously structured hydrogels, gradient hydrogels provide a better bio-mimicking microenvironment for combined cell therapies in chronic wound treatment by regulating various cell behaviors, such as proliferation, migration, and differentiation. Here, we present the integration of L929 mouse fibroblast spheroids into gradient hydrogels to mimic the dermal stiffness microenvironment and we investigated their impact on full-thickness skin regeneration. A stiffness gradient was achieved by modulating the concentration of methacrylated hyaluronic acid (HA-MA) with varying degrees of methacrylation, using a dual-syringe pump system. The encapsulation of L929 spheroids with gradient hydrogel facilitated skin cell organization in a hierarchically ordered configuration, leading to full-thickness wound healing that was 1.53 times faster than the untreated group in a rat model. This study provides a method for investigating the potential role of gradient hydrogels in various tissue engineering and regeneration applications.

PVA and PVP nanofibers combined with Helichrysum italicum oil preserve skin cell interactions, elasticity and proliferation

Development of electrospun nanofibers with suitable properties to promote wound healing is an advantage in developing non-invasive skin treatments. We showed the potential application of Polyvinyl acetate (PVA) and Polyvinylpyrrolidone (PVP) combined with Helichrysum italicum oil (HO) in wound healing. During this process, Tight junctions (TJs) play a crucial role in maintaining skin integrity. TJs are intercellular junctions composed of a variety of transmembrane proteins, including Occludin (OCLN), observed also in migrating epithelial cells. Changes in OCLN expression affect epidermal permeability, indicating an active role in the healing process. Within this context, we studied the OCLN expression during healing after scratch assay on Keratinocytes (HaCaT), by a confocal microscopic analysis. In addition, we evaluated the effect of treatment after scratch on cell elasticity by Atomic Force Microscopy (AFM) analysis. All results show a positive trend in cell proliferation and viability on HaCaT treated with functionalized nanofibers. These results were confirmed by the expression of genes involved in the early stages of the regenerative process. Understanding the cell mechanisms involved in skin changes during repair process would allow future application of nanomaterials combined with HO in vivo.

Insights into Liposomal and Gel-Based Formulations for Dermatological Treatments

Dermatological diseases pose a significant challenge due to their chronic nature, complex pathophysiology, and the need for effective, patient-friendly treatments. Recent advancements in liposomal and gel-based formulations have played a crucial role in improving drug delivery, therapeutic efficacy, and patient compliance. Liposomal formulations have garnered considerable attention in dermatology due to their ability to encapsulate both hydrophilic and lipophilic compounds, enabling controlled drug release and enhanced skin penetration. However, challenges such as formulation complexity, stability issues, and regulatory constraints remain. Similarly, gel-based formulations are widely used due to their ease of application, biocompatibility, and ability to retain active ingredients. However, they also face limitations, including restricted penetration depth, susceptibility to microbial contamination, and challenges in achieving sustained drug release. The integration of liposomal and gel-based technologies offers a promising strategy to overcome current challenges and optimize dermatological drug delivery. This review explores both well-established therapies and recent innovations, offering a comprehensive overview of their applications in the treatment of prevalent dermatological conditions. Ultimately, continued research is essential to refine these formulations, expanding their clinical utility and enhancing therapeutic effectiveness in dermatology.

Fabrication and biological properties of electrospun chitosan/polyethylene oxide nanofibrous scaffolds loaded with the Arctium lappa L. extract

Chitosan (CS)/polyethylene oxide (PEO)/Arctium lappa L. (A. lappa) scaffolds can be extensively used as wound dressings. Therefore, in this study, electrospinning and cross-linked with glutaraldehyde vapor fabricated CS/PEO scaffolds with a weight ratio (2:1) containing different extract concentrations (15, 25, and 35 wt%). The scaffolds were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), Gas chromatography mass spectrometry (GC-MS), tensile strength test, thermogravimetric analysis (TGA), antibacterial activity, and biocompatibility evaluations. The analysis of variance (ANOVA) was used to confirm the results of the experiments. From FE-SEM images, it was observed that smooth, uniform, and defect-free scaffolds were obtained at 20 kV applied voltage, 15 cm needle-to-collector distance, and 0.5 ml/h flow with an average diameter ranging from 221 to 345 nm. The ultimate tensile strength and Young's modulus of the CS/PEO/35 wt% extract cross-linked scaffold improved by 225 and 381 %, respectively, compared to CS/PEO nanofiber. Adding the 35 wt% extract into the polymer demonstrated that the gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) had a better zone of inhibition test than the gram-positive bacteria (Staphylococcus aureus). Finally, the biocompatibility assay confirmed the proliferative potential of 35 wt% extract within 48 h.

A Poly-γ-Glutamic Acid/ε-Polylysine Hydrogel: Synthesis, Characterization, and Its Role in Accelerated Wound Healing

Wound healing is a complex biological process involving inflammation, proliferation, and remodeling phases. Effective healing is essential for maintaining skin integrity, driving the need for advanced materials like hydrogels, known for their high water retention and tunable mechanical properties. In this study, we synthesized a biocompatible composite hydrogel composed of γ-polyglutamic acid (γ-PGA) and ε-polylysine (ε-PL) through a Schiff base reaction, forming a stable crosslinked network. Its physicochemical properties, including rheological behavior and swelling capacity, were systematically evaluated. Biocompatibility was assessed via in vitro hemolysis and cytotoxicity assays, and in vivo testing was performed using a full-thickness skin defect model in Sprague Dawley (SD) rats to evaluate wound-healing efficacy. The PGA-PL hydrogel demonstrated excellent physicochemical properties, with a maximum swelling ratio of 65.6%, and biocompatibility as evidenced by low hemolysis rates (<5%) and high cell viability (>80%). It promoted wound healing by inhibiting the inflammatory response, reducing levels of the inflammatory cytokine IL-6, enhancing angiogenesis, and accelerating collagen deposition. The hydrogel showed complete biodegradation within 21 days in vivo without inducing a significant inflammatory response and significantly accelerated wound healing, achieving an 86% healing rate within 7 days compared to 67% in the control group. The PGA-PL composite hydrogel exhibits excellent mechanical strength and biocompatibility, and its effective wound-healing capabilities lay the groundwork for future development and optimization in various tissue engineering applications.

Rapid in situ formation of a double cross-linked network hydrogels for wound healing promotion

The persistent challenge lies in accelerating wound healing. Bioactive hydrogels with in situ formation properties ensure that the dressing completely adheres to the wound and isolates it from external bacteria and microorganisms in order to meet the needs of damaged skin tissue for rapid hemostasis and wound healing. In this paper, hydrogel dressing that Polyacrylamide/Sodium alginate grafted with dopamine/Gelatin grafted with glycidyl methacrylate doped with Angelica sinensis polysaccharide was prepared (PDGA). Chemical cross-linking of PAAM by adding cross-linking agent to initiate free radical polymerization and photocross-linking by free radical polymerization of GMA-GEL under UV light irradiation are two cross-linking modes to construct dual-cross-linking network of PDGA hydrogel dressing. The hydrogel remains fluid when placed in a sealed syringe and solidify rapidly by photocross-linking when placed on the wound. Furthermore, the hydrogel demonstrated excellent biocompatibility and hematological safety. The interaction between angelica polysaccharides and integrins on the platelet surface facilitated an augmentation in platelet adhesion, activation, and aggregation, ultimately inducing rapid coagulation of the blood within 130 s in a mouse tail vein hemorrhage model. ASP can promote tissue healing by promoting cell proliferation around wounds and accelerating the formation of new blood vessels. In a mouse skin defect model, collagen deposition, blood vessel formation, hair follicle regeneration, and granulation tissue formation were observed due to the presence of angelica polysaccharides, showing significantly superior wound healing properties when compared to Tegaderm™ film. In addition, the expression of CD31 in skin wounds treated with PDGA was significantly upregulated. Consequently, PDGA multifunctional dressings exhibit considerable potential for in vitro hemostasis and skin wound repair applications.

Advancement of Nanomaterials- and Biomaterials-Based Technologies for Wound Healing and Tissue Regenerative Applications

Patients and healthcare systems face significant social and financial challenges due to the increasing number of individuals with chronic external and internal wounds that fail to heal. The complexity of the healing process remains a serious health concern, despite the effectiveness of conventional wound dressings in promoting healing. Recent advancements in materials science and fabrication techniques have led to the development of innovative dressings that enhance wound healing. To further expedite the healing process, novel approaches such as nanoparticles, 3D-printed wound dressings, and biomolecule-infused dressings have emerged, along with cell-based methods. Additionally, gene therapy technologies are being harnessed to generate stem cell derivatives that are more functional, selective, and responsive than their natural counterparts. This review highlights the significant potential of biomaterials, nanoparticles, 3D bioprinting, and gene- and cell-based therapies in wound healing. However, it also underscores the necessity for further research to address the existing challenges and integrate these strategies into standard clinical practice.

Poloxamer 407-Based Hydrogels Containing Rutin Increase the In Vitro and In Vivo Wound Healing Phenomena

Rutin is a flavonoid glycoside found in many plants, known for its various pharmacological properties. However, its therapeutic potential is limited by its low water solubility, which restricts its bioavailability. Poloxamer 407 (P407) is a multifunctional excipient, which has proven effective in delivering poorly water-soluble drugs and promoting the healing process. Based on this information, this study investigates the wound healing potential of rutin-loaded P407 hydrogels, as an innovative pharmaceutical formulation. In vitro scratch assays on human keratinocytes revealed that combining rutin with P407 significantly enhances cell proliferation as compared to the single components. Moreover, the proposed hydrogel improved wound healing more effectively in rats than the free drug or the commercial wound dressing DuoDERM. Histological analyses confirmed that the formulation increased epithelialization and collagen synthesis in injured epidermises. These findings provide a strong rationale for the use of rutin-loaded P407 hydrogels for the treatment of skin injuries.

Nanomanaging Chronic Wounds with Targeted Exosome Therapeutics

Chronic wounds pose a significant healthcare challenge, impacting millions of patients worldwide and burdening healthcare systems substantially. These wounds often occur as comorbidities and are prone to infections. Such infections hinder the healing process, complicating clinical management and proving recalcitrant to therapy. The environment within the wound itself poses challenges such as lack of oxygen, restricted blood flow, oxidative stress, ongoing inflammation, and bacterial presence. Traditional systemic treatment for such chronic peripheral wounds may not be effective due to inadequate blood supply, resulting in unintended side effects. Furthermore, topical applications are often impervious to persistent biofilm infections. A growing clinical concern is the lack of effective therapeutic modalities for treating chronic wounds. Additionally, the chemically harsh wound microenvironment can reduce the effectiveness of treatments, highlighting the need for drug delivery systems that can deliver therapies precisely where needed with optimal dosages. Compared to cell-based therapies, exosome-based therapies offer distinct advantages as a cell-free approach for chronic wound treatment. Exosomes are of endosomal origin and enable cell-to-cell communications, and they possess benefits, including biocompatibility and decreased immunogenicity, making them ideal vehicles for efficient targeting and minimizing off-target damage. However, exosomes are rapidly cleared from the body, making it difficult to maintain optimal therapeutic concentrations at wound sites. The hydrogel-based approach and development of biocompatible scaffolds for exosome-based therapies can be beneficial for sustained release and prolong the presence of these therapeutic exosomes at chronic wound sites. Engineered exosomes have been shown to possess stability and effectiveness in promoting wound healing compared to their unmodified counterparts. Significant progress has been made in this field, but further research is essential to unlock their clinical potential. This review seeks to explore the benefits and opportunities of exosome-based therapies in chronic wounds, ensuring sustained efficacy and precise delivery despite the obstacles posed by the wound environment.

A Comprehensive Review of Honey-Containing Hydrogel for Wound Healing Applications

Honey has long been recognized for its medicinal properties, particularly in wound healing. Recent advancements in material science have led to the development of honey-containing hydrogels, combining the natural healing properties of honey with the versatile characteristics of hydrogel matrices. These hydrogels offer numerous advantages, including high moisture retention, biocompatibility, and the controlled release of bioactive compounds, making them highly effective for wound healing applications. Hydrogels hold significant potential in advancing medical applications, particularly for cutaneous injuries. The diverse properties of honey, including antimicrobial, anti-inflammatory, and anti-eschar effects, have shown promise in accelerating tissue regeneration. According to studies, they are effective in maintaining a good swelling ratio index, Water Vapour Transmission Rate (WVTR), contact angle, tensile and elongation at break, in vitro biodegradation rate, viscosity and porosity analysis, lowering bacterial infections, and encouraging rapid tissue regeneration with notable FTIR peaks and SEM average pore sizes. However, limitations such as low bioavailability and inefficiencies in direct application reduce their therapeutic effectiveness at the wound site. Integrating honey into hydrogels can help preserve its wound healing mechanisms while enhancing its ability to facilitate skin tissue recovery. This review explores the underlying mechanisms of honey in wound healing management and presents an extensive analysis of honey-containing hydrogels reported in the literature over the past eight years. It emphasizes the physicochemical and mechanical effectiveness and advancements of honey-incorporated hydrogels in promoting skin wound healing and tissue regeneration, supported by evidence from both in vitro and in vivo studies. While honey-based therapies for wound healing have demonstrated promising outcomes in numerous in vitro and animal studies, clinical studies remain limited. Despite that, honey's incorporation into hydrogel systems, however, offers a potent fusion of contemporary material technology and natural healing qualities, marking a substantial breakthrough in wound treatment.

Development and Characterization of Biocompatible Chitosan-Aloe Vera Films Functionalized with Gluconolactone and Sorbitol for Advanced Wound Healing Applications

Chitosan (CTS) has emerged as a promising biopolymer for wound healing due to its biocompatibility, biodegradability, and intrinsic bioactive properties. This study explores the development and characterization of CTS-based films enhanced with natural bioactive agents, aloe vera (A), gluconolactone (GL), and sorbitol (S), to improve their mechanical, antimicrobial, and regenerative performance for potential use in advanced wound care. A series of CTS-based films were fabricated with varying concentrations of A, GL, and S, and their physicochemical, mechanical, and biological properties were comprehensively evaluated. Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) analysis revealed modifications in the film structure attributable to these additives, influencing the surface roughness, hydrophilicity, and thermal stability. Biocidal assays confirmed enhanced antimicrobial activity, particularly in films containing GL and A. Biodegradation studies demonstrated a significant enhancement in microbial decomposition of the films, while cytocompatibility tests confirmed minimal cytotoxic effects and improved cellular response. This research underscores the potential of combining CS with A, GL, and S to engineer multifunctional biomaterials tailored for effectively tackling different phases of the wound healing process, offering a sustainable and biocompatible alternative for clinical applications.

Advancements, functionalization techniques, and multifunctional applications in biomedical and industrial fields of electrospun pectin nanofibers: A review

Electrospun pectin nanofibers have emerged as a transformative advancement in biomaterials, offering remarkable potential across diverse biomedical and industrial applications. This review explores the synthesis, optimization, and versatile applications of electrospun pectin nanofibers, highlighting their unique properties, including biocompatibility, biodegradability, and adaptability for functionalization. Pectin's structural diversity, coupled with its ability to form hydrogels and interact with biological systems, makes it a promising candidate for wound healing, drug delivery, tissue engineering, and smart packaging. Electrospinning has enabled the fabrication of pectin nanofibers with tunable morphology and functionality, overcoming traditional limitations such as poor mechanical strength. Advances in blending pectin with other polymers and incorporating bioactive agents have further enhanced their mechanical, biological, and therapeutic properties. In wound healing, pectin nanofibers mimic the extracellular matrix, promote angiogenesis, and deliver bioactive compounds to accelerate tissue regeneration. Challenges such as scalability, regulatory compliance, and mechanical limitations remain barriers to widespread adoption. This review underscores the need for interdisciplinary research to address these challenges and advance the clinical and commercial translation of pectin nanofibers. By critically analyzing recent advancements and outlining future directions, this review highlights the transformative potential of electrospun pectin nanofibers as sustainable, high-performance biomaterials for modern biomedical and industrial applications.

Tissue macrophages: origin, heterogenity, biological functions, diseases and therapeutic targets

Macrophages are immune cells belonging to the mononuclear phagocyte system. They play crucial roles in immune defense, surveillance, and homeostasis. This review systematically discusses the types of hematopoietic progenitors that give rise to macrophages, including primitive hematopoietic progenitors, erythro-myeloid progenitors, and hematopoietic stem cells. These progenitors have distinct genetic backgrounds and developmental processes. Accordingly, macrophages exhibit complex and diverse functions in the body, including phagocytosis and clearance of cellular debris, antigen presentation, and immune response, regulation of inflammation and cytokine production, tissue remodeling and repair, and multi-level regulatory signaling pathways/crosstalk involved in homeostasis and physiology. Besides, tumor-associated macrophages are a key component of the TME, exhibiting both anti-tumor and pro-tumor properties. Furthermore, the functional status of macrophages is closely linked to the development of various diseases, including cancer, autoimmune disorders, cardiovascular disease, neurodegenerative diseases, metabolic conditions, and trauma. Targeting macrophages has emerged as a promising therapeutic strategy in these contexts. Clinical trials of macrophage-based targeted drugs, macrophage-based immunotherapies, and nanoparticle-based therapy were comprehensively summarized. Potential challenges and future directions in targeting macrophages have also been discussed. Overall, our review highlights the significance of this versatile immune cell in human health and disease, which is expected to inform future research and clinical practice.

Biomacromolecule chitosan carrying meglumine antimoniate coated on a silver/polyurethane nanocomposite as a wound dressing: Therapeutic efficacy on cutaneous leishmaniasis caused by Leishmania major in BALB/c mice

The high drug-carrying capacity and biocompatibility of chitosan (CS), a versatile biomacromolecule, have received special attention in recent years. This study focused on CS containing meglumine antimoniate (MA) for treating leishmaniasis, which was coated onto a silver/polyurethane (Ag.MA.CS/PUF). The newly synthesized nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma (ICP), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, field emission scanning electron microscope/energy dispersive spectroscopy (FESEM/EDS), and transmission electron microscopy (TEM). To confirm the in vivo results, we administered the Ag.MA.CS/PUF nanocomposite topically to skin lesions caused by L. major (MRHO/IR/75/ER) in 56 inbred BALB/c mice in intervention (n = 42) and control (n = 14) groups, once daily for four weeks. Skin lesion sizes and amastigote counts were measured before treatment and four weeks post-treatment. At these intervals, the average size of skin lesions in the Ag.MA.CS/PUF group decreased by 28 %, from 3.02 ± 0.98 to 2.17 ± 0.33 mm2. In contrast, the average size of lesions in the negative control group significantly increased from 3.58 ± 2.05 to 8.73 ± 5.15 mm2 (p < 0.05). Furthermore, the parasite load in the Ag.MA.CS/PUF nanocomposite group was significantly reduced by 80 % compared to the negative control group (p = 0.001). These findings suggest promising prospects for improving treatment outcomes in the future.

Using Three-Dimensional Bioprinting to Generate Realistic Models of Wound Healing

Significance: The skin serves as the primary defense against external stimuli, making it vulnerable to damage. Injuries can cause a dysregulated environment, resulting in chronic inflammation and inhibition of cell proliferation and migration, which delays recovery. Innovative approaches, such as three-dimensional (3D) bioprinting, can foster a controlled healing environment by promoting synergy between the skin microbiome and cells. Recent Advances: Traditional approaches to wound healing have focused on fostering an environment conducive to the interplay between cells, extracellular proteins, and growth factors. 3D bioprinting, a manufacturing technology with applications in tissue engineering, deposits biomaterial-based bioink containing living cells to fabricate custom-designed tissue scaffolds in a layer-by-layer fashion. This process controls the architecture and composition of a construct, producing multilayered and complex structures such as skin. Critical Issues: The selection of biomaterials for scaffolds has been a challenge when 3D skin tissue engineering. While prioritizing mechanical properties, current biomaterials often lack the ability to interact with environmental stimuli such as pH, temperature, or oxygen levels. Employing smart biomaterials that integrate bioactive molecules and adapt to external conditions could overcome these limitations. This innovation would enable scaffolds to create a sustainable wound-healing environment, fostering microbiome balance, reducing inflammation, and facilitating cellular recovery and tissue restoration, addressing critical gaps in existing wound care solutions. Future Directions: Novel bioink formulations for skin injury recovery are focused on improving long-term cell viability, proliferation, vascularization, and immune integration. Efficient recovery of the skin microbiome using bioactive molecules has the potential to create microenriched environments that support the recovery of the skin microbiome and restore immune regulation. This promising direction for future research aims to improve patient outcomes in wound care.

Decellularized Persian walnut leaf (Juglans regia) as a potential wound dressing scaffold: an experimental study

Introduction

Wound dressings often fall short of providing the multifunctional capabilities required for optimal wound healing, such as promoting cell migration, proliferation, and tissue regeneration. Decellularization of plant tissues has gained attention as a potential source of biomaterials for tissue engineering applications due to their favorable characteristics, including pre-existing vascular networks, interconnected porous structure, efficient water transport and retention, high surface area, and a diverse range of mechanical properties.

Methods

This study investigates the feasibility of using decellularized walnut leaves (DWL) as a novel scaffold for wound dressing in a mice model of excisional wounds. The decellularization and bleaching processes were carried out using various chemical agents. DNA and protein quantification and hematoxylin and eosin staining were performed to reveal the successful removal of cells in DWL. Scanning electron microscopy (SEM) was used to indicate that the normal structure of walnut leaves was preserved after chemical decellularization. Chemical characterization was conducted using Fourier-transform infrared (FTIR) and Raman spectroscopy to show the remaining bioactive molecules and components in the structure of DWL.

Results

Comparing tensile strength and surface roughness parameters, surface wettability, swelling, and porosity properties of native and DWL indicated no statistical differences between them. SEM analysis demonstrated that human mesenchymal stem cells excellently attach and proliferate on the DWL. Additionally, the biocompatibility and potential of DWL scaffolds to accelerate wound closure and enhance histopathological scores, collagen deposition, and epithelial thickness were observed in a mice model of excisional wounds.

Discussion

In conclusion, DWL shows promising potential for application as a skin wound dressing due to its biocompatibility, ability to promote cell attachment and proliferation, and efficacy in accelerating wound healing.

Biomimetic Hydrogels - Tools for Regenerative Medicine, Oncology, and Understanding Medical Gas Plasma Therapy

Biomimetic hydrogels enable biochemical, cell biology, and tissue-like studies in the third dimension. Smart hydrogels are also frequently used in tissue engineering and as drug carriers for intra- or extracutaneous regenerative medicine. They have also been studied in bio-sensor development, 3D cell culture, and organoid growth optimization. Yet, many hydrogel types, adjuvant components, and cross-linking methods have emerged over decades, diversifying and complexifying such studies. Here, an evaluative overview is provided, mapping potential applications to the corresponding hydrogel tuning. Strikingly, hydrogels are ideal for studying locoregional therapy modalities, such as cold medical gas plasma technology. These partially ionized gases produce various reactive oxygen species (ROS) types along with other physico-chemical components such as ions and electric fields, and the spatio-temporal effects of these components delivered to diseased tissues remain largely elusive to date. Hence, this work outlines the promising applications of hydrogels in biomedical research in general and cold plasma science in particular and underlines the great potential of these smart scaffolds for current and future research and therapy.

Polyphenols in wound healing: unlocking prospects with clinical applications

Wound healing is a multifaceted, complex process that factors like aging, metabolic diseases, and infections may influence. The potentiality of polyphenols, natural compounds, has shown anti-inflammatory and antimicrobial properties in promoting wound healing and their potential applications in wound management. The studies reviewed indicate that polyphenols have multiple mechanisms that promote wound healing. This involves enhancing antioxidant defenses, reducing oxidative stress, modulating inflammatory responses, improving healing times, reducing infection rates, and enhancing tissue regeneration in clinical trials and in vivo and in vitro studies. Polyphenols have been proven to be effective in managing hard-to-heal wounds, especially in diabetic and elderly populations. Polyphenols have shown significant benefits in promoting angiogenesis and stimulating collagen synthesis. Polyphenol treatment has been demonstrated to have therapeutic effects in wound healing and chronic wound management. Their ability to regulate key healing processes makes them suitable for new wound care products and treatments. Future research should enhance formulations and delivery methods to optimize polyphenols' bioavailability and therapeutic efficacy in wound management approaches.

Comparative effects of various extracellular vesicle subpopulations derived from clonal mesenchymal stromal cells on cultured fibroblasts in wound healing-related process

INTRODUCTION

Non-healing wounds pose significant challenges and require effective therapeutic interventions. Extracellular vesicles (EVs) have emerged as promising cell-free therapeutic agents in tissue regeneration. However, the functional differences between different subpopulations of EVs in wound healing remain understudied. This study aimed to evaluate the effects of two distinct subpopulations of clonal mesenchymal stromal cells (cMSC)-derived EVs (cMSC-EVs), namely 20 K and 110K-cMSC-EVs, primarily on in vitro wound healing process, providing fast and cost-effective alternatives to animal models.

METHODS

In vitro assays were conducted to compare the effects of 20 K and 110K-cMSC-EVs, isolated through high-speed centrifugation and differential ultracentrifugation, respectively. For evaluation the main mechanisms of wound healing, including cell proliferation, cell migration, angiogenesis, and contraction. Human dermal fibroblasts (HDF) were considered as the main cells for analysis of these procedures. Moreover, gene expression analysis was performed to assess the impact of these EV subpopulations on the related process of wound healing on HDF.

RESULTS

The results demonstrated that both 20 K and 110K-cMSC-EVs exhibited beneficial effects on cell proliferation, cell migration, angiogenesis, and gel contraction. RT-qPCR revealed that both EV types downregulated interleukin 6 (IL6), induced proliferation by upregulating proliferating cell nuclear antigen (PCNA), and regulated remodeling by upregulating matrix metallopeptidase 1 (MMP1) and downregulating collagen type 1 (COL1).

DISCUSSION

This study highlights the effects of both 20 K and 110K-cMSC-EVs on the potency of HDFs in wound healing-related process. As the notable finding, 20K-cMSC-EVs offer a more feasible and cost-effective subpopulation for isolation and follow the GMP standard, recommended to utilize this fraction for therapeutic application.

Skin Deep and Beyond: Unravelling B Cell Extracellular Matrix Interactions in Cutaneous Immunity and Disease

The extracellular matrix (ECM) is a crucial component in multicellular organisms, serving as both a structural scaffold and active signalling units. While the role of the ECM, namely, to maintain homeostasis and steer adaptive immunity, is well described in secondary lymphoid organs, it is underappreciated in the skin-despite remarkable molecular similarity. Here, we examine how the specialised organisation of the ECM influences B cell development and function in both skin and secondary lymphoid organs with a special focus on ECM-integrin signalling. We discuss the presence and function of B cells in healthy and diseased skin, including their role in wound healing, autoimmune responses and inflammatory conditions. Additionally, we explore the formation of tertiary lymphoid structures in chronic skin diseases as a window into studying B cell-ECM interactions. By integrating fundamental immunology with skin biology, we aim to identify key knowledge gaps and explore potential clinical implications of B cell-ECM interactions in dermatology and beyond.

Functional Properties of Gelatin-Alginate Hydrogels for Use in Chronic Wound Healing Applications

In this study, a hydrogel material based on porcine gelatin and sodium alginate was synthesized for use as a dressing for chronic wound treatment. The hydrogels were covalently cross-linked using polyethylene glycol diglycidyl ether (PEGDE 500), and the interaction between the components was confirmed via FTIR. The properties of the resulting hydrogels were examined, including gel-fraction volume, swelling degree in different media, mechanical properties, pore size, cytotoxicity, and the ability to absorb and release analgesics (lidocaine, novocaine, sodium diclofenac). The hydrogel's resistance to enzymatic action by protease was enhanced both through chemical cross-linking and physical interactions between gelatin and alginate. The absorption capacity of the hydrogels, reaching 90 g per dm2 of the hydrogel dressing, indicates their potential for absorbing wound exudates. It was demonstrated that the antiseptic (chlorhexidine) contained in the structured gelatin-alginate hydrogels can be released into an infected substrate, resulting in a significant inhibition of pathogenic microorganisms (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus niger). These results clearly demonstrate that the obtained hydrogel materials can serve as non-traumatic dressings for the treatment of chronic and/or infected wounds.

Engineering Gas-Releasing Nanomaterials for Efficient Wound Healing

The escalating prevalence of tissue damage and its associated complications has elicited global apprehension. While nanomaterial-based wound healing exhibits significant potential in terms of curbing infections and surpassing conventional methods, unresolved concerns regarding nanomaterial controllability and precision remain unresolved, jeopardizing its practical applications. In recent years, a unique strategy for creating gas-releasing nanomaterials for wound repair has been proposed, involving the creation of gas-releasing nanomaterials to facilitate wound repair by generating gas donor moieties. The operational spatiotemporal responsiveness and broad-spectrum antibacterial properties of these gases, combined with their inability to generate bacterial resistance like traditional antibiotics, establish their efficacy in addressing chronic non-healing wounds, specifically diabetic foot ulcers (DFUs). In this review, we delve into the intricacies of wound healing process, emphasizing the chemical design, functionality, bactericidal activity, and potential of gas-release materials, encompassing NO, CO, H2S, O2, CO2, and H2, for effective wound healing. Furthermore, we explore the advancements in synergistic therapy utilizing these gases, aiming to enhance our overall comprehension of this field. The insights gleaned from this review will undoubtedly aid researchers and developers in the creation of promising gas-releasing nanomaterials, thus propelling efficient wound healing in the future.

Vitamin C: A Comprehensive Review of Its Role in Health, Disease Prevention, and Therapeutic Potential

Since Albert Szent-Györgyi discovered it and it became used in treating scurvy, vitamin C has attracted interest in many studies due to its unique properties. It is an important cofactor in the synthesis of collagen and hormones, and it is involved in immunity, iron absorption, and processes requiring antioxidants. Thus, this review aims to emphasize the importance and usefulness of vitamin C in improving quality of life and preventing various diseases (e.g., chronic diseases, cardiovascular diseases, cancer) but also for its use in treatments against infections, neurodegenerative diseases, and cancer. Although the studies presented provide essential information about the properties of VIC and its beneficial effect on health, some studies contradict these theories. In this respect, further studies on larger samples and over a longer period are needed to demonstrate the therapeutic potential of this nutrient. However, VIC remains a necessary vitamin that should be consumed daily to maintain optimal health and prevent deficiencies that can lead to scurvy and its associated complications.

HEALS-A and GRADES: Novel Histological and Clinical Scales for Assessing Skin Regeneration in Murine Wound Healing Models

Background: Wounds affect approximately 15 out of every 1000 individuals, representing a significant healthcare challenge. The preclinical evaluation of novel wound treatments is important for advancing therapies that promote effective skin regeneration and improve healing outcomes. Methods: In this study, we integrated existing knowledge from the literature on murine wound healing models, histological features of the skin, and clinical scores described in humans to propose two complementary assessment tools: the HEALS-A histological score (healing, epithelialization, angiogenesis, leukocytes, scar tissue, appendages) and the GRADES clinical score (granulation tissue, redness/edema, appearance of wound, devitalized tissue). Results: These scales combine real-time clinical observation with detailed histological analysis, providing a practical and comprehensive approach to assessing wound healing. Unlike existing wound assessing approaches, HEALS-A does not require specialized software and considers regenerated tissue structures, ensuring a broader and more-detailed evaluation. Conclusions: The assessment of wound closure over time, combined with clinical evaluation and histological analysis of skin, provides a comprehensive approach to determining the true impact of new treatments on skin regeneration and the recovery of its functions in wounds.

Collagen as a bio-ink for 3D printing: a critical review

The significance of three-dimensional (3D) bioprinting in the domain of regenerative medicine and tissue engineering is readily apparent. To create a multi-functional bioinspired structure, 3D bioprinting requires high-performance bioinks. Bio-inks refer to substances that encapsulate viable cells and are employed in the printing procedure to construct 3D objects progressive through successive layers. For a bio-ink to be considered high-performance, it must meet several critical criteria: printability, gelation kinetics, structural integrity, elasticity and strength, cell adhesion and differentiation, mimicking the native ECM, cell viability and proliferation. As an exemplar application, tissue grafting is used to repair and replace severely injured tissues. The primary considerations in this case include compatibility, availability, advanced surgical techniques, and potential complications after the operation. 3D printing has emerged as an advancement in 3D culture for its use as a regenerative medicine approach. Thus, additive technologies such as 3D bioprinting may offer safe, compatible, and fast-healing tissue engineering options. Multiple methods have been developed for hard and soft tissue engineering during the past few decades, however there are many limitations. Despite significant advances in 3D cell culture, 3D printing, and material creation, a gold standard strategy for designing and rebuilding bone, cartilage, skin, and other tissues has not yet been achieved. Owing to its abundance in the human body and its critical role in protecting and supporting human tissues, soft and hard collagen-based bioinks is an attractive proposition for 3D bioprinting. Collagen, offers a good combination of biocompatibility, controllability, and cell loading. Collagen made of triple helical collagen subunit is a protein-based organic polymer present in almost every extracellular matrix of tissues. Collagen-based bioinks, which create bioinspired scaffolds with multiple functionalities and uses them in various applications, is a represent a breakthrough in the regenerative medicine and biomedical engineering fields. This protein can be blended with a variety of polymers and inorganic fillers to improve the physical and biological performance of the scaffolds. To date, there has not been a comprehensive review appraising the existing literature surround the use of collagen-based bioink applications in 'soft' or 'hard' tissue applications. The uses of the target region in soft tissues include the skin, nerve, and cartilage, whereas in the hard tissues, it specifically refers to bone. For soft tissue healing, collagen-based bioinks must meet greater functional criteria, whereas hard tissue restoration requires superior mechanical qualities. Herein, we summarise collagen-based bioink's features and highlight the most essential ones for diverse healing situations. We conclude with the primary challenges and difficulties of using collagen-based bioinks and suggest future research objectives.

Exploiting the Molecular Properties of Fibrinogen to Control Bleeding Following Vascular Injury

The plasma protein fibrinogen is critical for haemostasis and wound healing, serving as the structural foundation of the blood clot. Through a complex interaction between coagulation factors, the soluble plasma fibrinogen is converted to insoluble fibrin networks, which form the skeleton of the blood clot, an essential step to limit blood loss after vascular trauma. This review examines the molecular mechanisms by which fibrinogen modulates bleeding, focusing on its interactions with other proteins that maintain fibrin network stability and prevent premature breakdown. Moreover, we also cover the role of fibrinogen in ensuring clot stability through the physiological interaction with platelets. We address the therapeutic applications of fibrinogen across various clinical contexts, including trauma-induced coagulopathy, postpartum haemorrhage, and cardiac surgery. Importantly, a full understanding of protein function will allow the development of new therapeutics to limit blood loss following vascular trauma, which remains a key cause of mortality worldwide. While current management strategies help with blood loss following vascular injury, they are far from perfect and future research should prioritise refining fibrinogen replacement strategies and developing novel agents to stabilise the fibrin network. Exploiting fibrinogen's molecular properties holds significant potential for improving outcomes in trauma care, surgical interventions and obstetric haemorrhage.

New Perspectives of Hydrogels in Chronic Wound Management

Chronic wounds pose a substantial healthcare concern due to their prevalence and cost burden. This paper presents a detailed overview of chronic wounds and emphasizes the critical need for novel therapeutic solutions. The pathophysiology of wound healing is discussed, including the healing stages and the factors contributing to chronicity. The focus is on diverse types of chronic wounds, such as diabetic foot necrosis, pressure ulcers, and venous leg ulcers, highlighting their etiology, consequences, and the therapeutic issues they provide. Further, modern wound care solutions, particularly hydrogels, are highlighted for tackling the challenges of chronic wound management. Hydrogels are characterized as multipurpose materials that possess vital characteristics like the capacity to retain moisture, biocompatibility, and the incorporation of active drugs. Hydrogels' effectiveness in therapeutic applications is demonstrated by how they support healing, including preserving ideal moisture levels, promoting cellular migration, and possessing antibacterial properties. Thus, this paper presents hydrogel technology's latest developments, emphasizing drug-loaded and stimuli-responsive types and underscoring how these advanced formulations greatly improve therapy outcomes by enabling dynamic and focused reactions to the wound environment. Future directions for hydrogel research promote the development of customized hydrogel treatments and the incorporation of digital health tools to improve the treatment of chronic wounds.

Biocompatibility of Phosphorus Dendrimers and Their Antibacterial Properties as Potential Agents for Supporting Wound Healing

Dendrimers are a wide range of nanoparticles with desirable properties that can be used in many areas of medicine. However, little is known about their potential use in wound healing. This study examined the properties of phosphorus dendrimers that were built on a cyclotriphosphazene core and pyrrolidinium (DPP) or piperidinium (DPH) terminated groups, to be used as potential factors that support wound healing (in vitro). Therefore, the degree of toxicity of the tested compounds for human erythrocytes and the human fibroblast cell line (BJ) was determined, and it was found that at low concentrations, the tested compounds are compatible with blood. The influence of phosphorus dendrimers on plasma proteins (human serum albumin (HSA) and fibrinogen) was examined, with a lack of conformational changes in the structure of these proteins, suggesting that their physiological function was not disturbed. The effects on plasma coagulation cascade and fibrinolysis were also assessed, and it was found that phosphorus dendrimers in low concentrations are blood compatible and interfere neither with coagulation processes nor in clot breakdown. Skin injuries, especially chronic wounds, are also susceptible to infection; therefore, the antimicrobial potential of dendrimers was tested, and it was found that these dendrimers had antibacterial activity against both Gram-negative and Gram-positive bacteria. The highest activity of the tested compounds was found for higher applied concentrations.

Copper-Based Nanozymes: Potential Therapies for Infectious Wounds

Bacterial infections are a significant obstacle to the healing of acute and chronic wounds, such as diabetic ulcers and burn injuries. Traditional antibiotics are the primary treatment for bacterial infections, but they present issues such as antibiotic resistance, limited efficacy, and potential side effects. This challenge leads to the exploration of nanozymes as alternative therapeutic agents. Nanozymes are nanomaterials with enzyme-like activities. Owing to their low production costs, high stability, scalability, and multifunctionality, nanozymes have emerged as a prominent focus in antimicrobial research. Among various types of nanozymes, metal-based nanozymes offer several benefits, including broad-spectrum antimicrobial activity and robust catalytic properties. Specifically, copper-based nanozymes (CuNZs) have shown considerable potential in promoting wound healing. They exhibit strong antimicrobial effects, reduce inflammation, and enhance tissue regeneration, making them highly advantageous for use in wound care. This review describes the dual functions of CuNZs in combating infection and facilitating wound repair. Recent advancements in the design and synthesis of CuNZs, evaluating their antimicrobial efficacy, healing promotion, and biosafety both in vitro and in vivo on the basis of their core components, are critically important.

Advancements in 3D skin bioprinting: processes, bioinks, applications and sensor integration

This comprehensive review explores the multifaceted landscape of skin bioprinting, revolutionizing dermatological research. The applications of skin bioprinting utilizing techniques like extrusion-, droplet-, laser- and light-based methods, with specialized bioinks for skin biofabrication have been critically reviewed along with the intricate aspects of bioprinting hair follicles, sweat glands, and achieving skin pigmentation. Challenges remain with the need for vascularization, safety concerns, and the integration of automated processes for effective clinical translation. The review further investigates the incorporation of biosensor technologies, emphasizing their role in monitoring and enhancing the wound healing process. While highlighting the remarkable progress in the field, critical limitations and concerns are critically examined to provide a balanced perspective. This synthesis aims to guide scientists, engineers, and healthcare providers, fostering a deeper understanding of the current state, challenges, and future directions in skin bioprinting for transformative applications in tissue engineering and regenerative medicine.

Revealing the promising era of silk-based nanotherapeutics: a ray of hope for chronic wound healing treatment

Chronic wounds significantly contribute to disability and affect the mortality rate in diabetic patients. In addition, pressure ulcers, diabetic foot ulcers, arterial ulcers, and venous ulcers pose a significant health burden due to their associated morbidity and death. The complex healing process, environmental factors, and genetic factors have been identified as the rate-limiting stages of chronic wound healing. Changes in temperature, moisture content, mechanical strain, and genetics can result in slow wound healing, increased susceptibility to bacterial infections, and poor matrix remodelling. These obstacles can be addressed with natural biomaterials exhibiting antimicrobial, collagen synthesis, and granulation tissue formation properties. Recently, silk proteins have gained significant attention as a natural biomaterial owing to good biocompatibility, biodegradability, reduced immunogenicity, ease of sterilization, and promote the wound healing process. The silk components such as sericin and fibroin in combination with nano(platforms) effectively promote wound repair. This review emphasises the potential of sericin and fibroin when combined with nano(platforms) like nanoparticles, nanofibers, and nanoparticles-embedded films, membranes, gels, and nanofibers.