Injectable nanoparticle-crosslinked xyloglucan/ε-poly-l-lysine composite hydrogel with hemostatic, antimicrobial, and angiogenic properties for infected wound healing

Skin wounds are susceptible to infection, leading to severe inflammatory reactions that can progress to chronic wounds, ultimately causing significant physical and mental distress to the patient. In this study, we propose an injectable composite hydrogel achieved through one-pot gelation of oxidized xyloglucan (OXG), cationic polyamide ε-poly-l-lysine (EPL), and surface amino-rich silicon nanoparticles (SiNPs). OXG exhibits commendable anti-inflammatory properties and provides crosslinking sites. SiNPs serve as mechanically reinforced crosslinkers, facilitating the construction of a dynamic Schiff base network. SiNPs significantly reduced the gelation time to 3 s and tripled the storage modulus of the hydrogels. Additionally, the combination of EPL and SiNPs demonstrated synergistic antimicrobial activity against both S. aureus and E. coli. Notably, the hydrogel effectively halted liver bleeding within 30 s. The hydrogel demonstrated outstanding shear-thinning and self-healing properties, crucial considerations for the design of injectable hydrogels. Furthermore, its efficacy was evaluated as a wound dressing in a mouse model with S. aureus infection. The results indicated that, compared to commercial products, the hydrogel exhibited a shorter wound healing time, decreased inflammation, thinner epithelium, increased hair follicles, enhanced neovascularization, and more substantial collagen deposition. These findings strongly suggest the promising potential of the proposed hydrogel as an effective wound dressing for the treatment of infected wounds.

Bone marrow derived mesenchymal stem cells enriched PCL-gelatin nanofiber scaffold for improved wound healing

Electrospun nanofibers exhibit a significant potential in the synthesis of nanostructured materials, thereby offering a promising avenue for enhancing the efficacy of wound care. The present study aimed to investigate the wound-healing potential of two biomacromolecules, PCL-Gelatin nanofiber adhered with bone marrow-derived mesenchymal stem cells (BMSCs). Characterisation of the nanofiber revealed a mean fiber diameter ranging from 200 to 300 nm, with distinctive elemental peaks corresponding to polycaprolactone (PCL) and gelatin. Additionally, BMSCs derived from bone marrow were integrated into nanofibers, and their wound-regenerative potential was systematically evaluated through both in-vitro and in-vivo methodologies. In-vitro assessments substantiated that BMSC-incorporated nanofibers enhanced cell viability and crucial cellular processes such as adhesion, and proliferation. Subsequently, in-vivo studies were performed to demonstrate the wound-healing efficacy of nanofibers. It was observed that the rate of wound healing of BMSCs incorporated nanofibers surpassed both, nanofiber and BMSCs alone. Furthermore, histomorphological analysis revealed accelerated re-epithelization and improved wound contraction in BMSCs incorporated nanofiber group. The fabricated nanofiber incorporated with BMSCs exhibited superior wound regeneration in animal model and may be utilised as a wound healing patch.

Instantly adhesive and ultra-elastic patches for dynamic organ and wound repair

Bioadhesive materials and patches are promising alternatives to surgical sutures and staples. However, many existing bioadhesives do not meet the functional requirements of current surgical procedures and interventions. Here, we present a translational patch material that exhibits instant adhesion to tissues (2.5-fold stronger than Tisseel, an FDA-approved fibrin glue), ultra-stretchability (stretching to >300% its original length without losing elasticity), compatibility with rapid photo-projection (<2 min fabrication time/patch), and ability to deliver therapeutics. Using our established procedures for the in silico design and optimization of anisotropic-auxetic patches, we created next-generation patches for instant attachment to tissues while conforming to a broad range of organ mechanics ex vivo and in vivo. Patches coated with extracellular vesicles derived from mesenchymal stem cells demonstrate robust wound healing capability in vivo without inducing a foreign body response and without the need for patch removal that can cause pain and bleeding. We further demonstrate a single material-based, void-filling auxetic patch designed for the treatment of lung puncture wounds.

Granular Biomaterials as Bioactive Sponges for the Sequestration and Release of Signaling Molecules

A major challenge for the regeneration of chronic wounds is an underlying dysregulation of signaling molecules, including inflammatory cytokines and growth factors. To address this, it is proposed to use granular biomaterials composed of jammed microgels, to enable the rapid uptake and delivery of biomolecules, and provide a strategy to locally sequester and release biomolecules. Sequestration assays on model biomolecules of different sizes demonstrate that granular hydrogels exhibit faster transport than comparable bulk hydrogels due to enhanced surface area and decreased diffusion lengths. To demonstrate the potential of modular granular hydrogels to modulate local biomolecule concentrations, microgel scaffolds are engineered that can simultaneously sequester excess pro-inflammatory factors and release pro-healing factors. To target specific biomolecules, microgels are functionalized with affinity ligands that bind either to interleukin 6 (IL-6) or to vascular endothelial growth factor A (VEGF-A). Finally, disparate microgels are combined into a single granular biomaterial for simultaneous sequestration of IL-6 and release of VEGF-A. Overall, the potential of modular granular hydrogels is demonstrated to locally tailor the relative concentrations of pro- and anti-inflammatory factors.

Tissue Regeneration and Remodeling in Rat Models after Application of Hypericum perforatum L. Extract-Loaded Bigels

The wound-healing effect of St. John's Wort (SJW) is mainly attributed to hyperforin (HP), but its low stability restricts its topical administration. This study investigates how "free" HP-rich SJW extract (incorporated into a bigel; B/SJW) and extract "protected" by nanostructured lipid carriers (also included in a biphasic semisolid; B/NLC-SJW) affect tissue regeneration in a rat skin excision wound model. Wound diameter, histological changes, and tissue gene expression levels of fibronectin (Fn), matrix metalloproteinase 8 (MMP8), and tumor necrosis factor-alpha (TNF-α) were employed to quantify the healing progress. A significant wound size reduction was achieved after applying both extract-containing semisolids, but after a 21-day application period, the smallest wound size was observed in the B/NLC-SJW-treated animals. However, the inflammatory response was affected more favorably by the bigel containing the "free" SJW extract, as evidenced by histological studies. Moreover, after the application of B/SJW, the expression of Fn, MMP8, and TNF-α was significantly higher than in the positive control. In conclusion, both bigel formulations exhibited beneficial effects on wound healing in rat skin, but B/SJW affected skin restoration processes in a comprehensive and more efficient way.

Human keratin matrices promote wound healing by modulating skin cell expression of cytokines and growth factors

A wide variety of biomaterials has been developed to assist in wound healing, including acellular animal and human-derived protein matrices. However, millions of patients worldwide still suffer from non-healing chronic wounds, demonstrating a need for further innovation in wound care. To address this need, a novel biomaterial, the human keratin matrix (HKM), was developed, characterised, and tested in vitro and in vivo. HKM was found to be degradation-resistant, and a proteomics analysis showed it to be greater than 99% human keratin proteins. PCR revealed adult human epidermal keratinocytes (HEKa) grown in contact with HKM showed increased gene expression of keratinocyte activations markers such as Epidermal Growth Factor (EGF). Additionally, a cytokine microarray demonstrated culture on HKM increased the release of cytokines involved in wound inflammatory modulation by both HEKa cells and adult human dermal fibroblasts (HDFa). Finally, in a murine chronic wound model, full-thickness wounds treated weekly with HKM were smaller through the healing process than those treated with human amniotic membrane (AM), bovine dermis (BD), or porcine decellularized small intestinal submucosa (SIS). HKM-treated wounds also closed significantly faster than AM- and SIS-treated wounds. These data suggest that HKM is an effective novel treatment for chronic wounds.

Mathematical and numerical analyses of cellular, molecular and angiogenic parameters of a rat skin wound healing model

The inflammatory phase is an important event in the skin wound healing process. The deposition of granulation tissue in the wound bed and the rebuilding of the vascular network occur as inflammation diminishes. An angiogenic component in the formation of granulation tissue is the secretion of vascular endothelial growth factor, which assists in the chemotaxis, proliferation, and replication of fibroblasts. In this paper, we develop a mathematical model of skin wound healing angiogenic factors based on inflammatory cells (macrophages and neutrophils) and mediators (interleukin 6 and interleukin 10). We highlight the importance of this process in vascular endothelial growth factor release and in the formation of new capillary tips. We used a mathematical model of partial differential equations based on the reaction-diffusion-advection equations. In order to calibrate the parameters, we considered an in vivo model composed by four treatments: hydroalcoholic extract and oil-resin of Copaifera langsdorffii at 10% concentration, collagenase, and Lanette cream. Using the laboratory data for the wound edge, our mathematical model estimated the values of vascular endothelial growth factor concentration, and tips density in the center of the wound with a maximum error of 2.9%, and predicted healing time required for each treatment. The region of viability for the parameters, in the proposed model, was found through numerical simulations from the Interleukin 6 and 10 dysregulation and we obtained that, among the parameters analyzed, the greatest influencer in the dynamics of the system is the one, which represents the production of Interleukin 10 during phagocytosis.

Copaifera langsdorffii Oleoresin-Loaded Nanostructured Lipid Carrier Emulgel Improves Cutaneous Healing by Anti-Inflammatory and Re-Epithelialization Mechanisms

The skin is essential to the integrity of the organism. The disruption of this organ promotes a wound, and the organism starts the healing to reconstruct the skin. Copaifera langsdorffii is a tree used in folk medicine to treat skin affections, with antioxidant and anti-inflammatory properties. In our study, the oleoresin of the plant was associated with nanostructured lipid carriers, aiming to evaluate the healing potential of this formulation and compare the treatment with reference drugs used in wound healing. Male Wistar rats were used to perform the excision wound model, with the macroscopic analysis of wound retraction. Skin samples were used in histological, immunohistochemical, and biochemical analyses. The results showed the wound retraction in the oleoresin-treated group, mediated by α-smooth muscle actin (α-SMA). Biochemical assays revealed the anti-inflammatory mechanism of the oleoresin-treated group, increasing interleukin-10 (IL-10) concentration and decreasing pro-inflammatory cytokines. Histopathological and immunohistochemical results showed the improvement of re-epithelialization and tissue remodeling in the Copaifera langsdorffii group, with an increase in laminin-γ2, a decrease in desmoglein-3 and an increase in collagen remodeling. These findings indicate the wound healing potential of nanostructured lipid carriers associated with Copaifera langsdorffii oleoresin in skin wounds, which can be helpful as a future alternative treatment for skin wounds.

Myco-Synthesized Selenium Nanoparticles as Wound Healing and Antibacterial Agent: An In Vitro and In Vivo Investigation

Bacterial-associated wound infections are an obstacle for individuals and the medical industry. Developing versatile, antibiotic-free therapies helps heal wounds more quickly and efficiently. In the current study, fungal metabolites were employed as a reducing agent in fabricating selenium nanoparticles (SeNPs) for improved antibacterial and wound healing properties. Utilizing UV-visible spectroscopy, dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), and electron microscopic examination, the properties of the synthesized nanoparticles were extensively evaluated. Myco-synthesized SeNPs demonstrated strong antibacterial activity against Staphylococcus aureus ATCC 6538 with a minimum inhibitory concentration of 0.3125 mg/mL, reducing cell number and shape distortion in scanning electron microscope (SEM) images. SeNPs' topical administration significantly reduced wound area and healing time, exhibiting the least bacterial load after six days compared to controls. After six and 11 days of treatment, SeNPs could decrease proinflammatory cytokines IL-6 and TNF-α production. The histopathological investigation showed a healed ulcer with moderate infiltration of inflammatory cells after exposing mice's skin to SeNPs for six and 11 days. The docking interaction indicated that SeNPs were highly efficient against the IL-6 and TNF-α binding receptors. These findings imply that myco-fabricated SeNPs might be used as topically applied antimicrobial agents for treating skin infections and wounds.

Composite Hydrogels with Embedded Silver Nanoparticles and Ibuprofen as Wound Dressing

The wound healing process is often slowed down as a result of complications from bacterial infections and inflammatory reactions. Therefore, it is necessary to develop dressings with fast antibacterial and anti-inflammatory activity that shorten the wound healing period by promoting cell migration and proliferation. Chitosan (CS)-based hydrogels have been widely studied for their antibacterial and wound healing capabilities. Herein, we developed a composite hydrogel based on CS and PVA embedding silver nanoparticles (AgNPs) with antibacterial properties and ibuprofen (Ib) as an anti-inflammatory agent. The hydrogel prepared by double physical cross-linking, with oxalic acid and by freeze-thawing, loaded with 0.225 wt.% AgNPs and 0.264 wt.% Ib, displayed good mechanical properties (compressive modulus = 132 kPa), a high swelling degree and sustained drug delivery (in simulated skin conditions). Moreover, the hydrogel showed strong antibacterial activity against S. aureus and K. pneumoniae due to the embedded AgNPs. In vivo, this hydrogel accelerated the wound regeneration process through the enhanced expression of TNF alpha IP8, by activating downstream cascades and supporting the healing process of inflammation; Cox2, which enhances the migration and proliferation of cells involved in re-epithelization and angiogenesis; MHCII, which promotes immune cooperation between local cells, eliminating dead tissue and controlling infection; the intense expression of Col I as a major marker in the tissue granulation process; and αSMA, which marks the presence of myofibroblasts involved in wound closure and indicates ongoing re-epithelization. The results reveal the potential healing effect of CS/PVA/AgNPs/Ib hydrogels and suggest their potential use as wound dressings.

Electrospun polyvinyl alcohol/Withania somnifera extract nanofibers incorporating tadalafil-loaded nanoparticles for diabetic ulcers

Background: Impaired inflammation and vascularization are common reasons for delayed diabetic wound healing. Nanoparticles (NPs)-in-nanofibers composites can manage diabetic wounds. A multifunctional scaffold was developed based on tadalafil (TDF)-loaded NPs incorporated into polyvinyl alcohol/Withania somnifera extract nanofibers. Materials & methods: TDF-loaded NPs were prepared and fully characterized in terms of their physicochemical properties. Extract of ashwagandha was prepared and a blend composed of TDF-loaded NPs, herbal extract and polyvinyl alcohol was used to prepare the whole composite. Results: The whole composite exhibited improved wound closure in a diabetic rat model in terms of reduced inflammation and enhanced angiogenesis. Conclusion: Results suggest that this multifunctional composite could serve as a promising diabetic wound dressing.

Investigating the active chemical constituents and pharmacology of Nanocnide lobata in the treatment of burn and scald injuries

OBJECTIVE

To identify the most effective fraction of Nanocnide lobata in the treatment of burn and scald injuries and determine its bioactive constituents.

METHODS

Chemical identification methods were used to analyze solutions extracted from Nanocnide lobata using petroleum ether, ethyl acetate, n-butanol using a variety of color reactions. The chemical constituents of the extracts were identified by ultra-performance liquid chromatography (UPLC)-mass spectrometry (MS). A total of 60 female mice were randomly divided into the following 6 groups: the petroleum ether extract-treated group; the ethyl acetate extract-treated group; the n-butanol extract-treated group; the model group; the control group; and the positive drug group. The burn/scald model was established using Stevenson's method. At 24 hours after modeling, 0.1 g of the corresponding ointment was evenly applied to the wound in each group. Mice in the model group did not undergo treatment, while those in the control group received 0.1 g of Vaseline. Wound characteristics, including color, secretions, hardness, and swelling, were observed and recorded. Photos were taken and the wound area calculated on the 1st, 5th, 8th, 12th, 15th, 18th and 21st days. Hematoxylin-eosin (HE) staining was utilized to observe the wound tissue of mice on the 7th, 14th, and 21st days. An enzyme-linked immunosorbent assay (ELISA) kit was used to measure the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-10, vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β1.

RESULTS

The chemical constituents of Nanocnide lobata mainly include volatile oils, coumarins, and lactones. UPLC-MS analysis revealed 39 main compounds in the Nanocnide lobata extract. Among them, ferulic acid, kaempferitrin, caffeic acid, and salicylic acid have been confirmed to exhibit anti-inflammatory and antioxidant activity related to the treatment of burns and scalds. HE staining revealed a gradual decrease in the number of inflammatory cells and healing of the wounds with increasing time after Nanocnide lobata extract administration. Compared with the model group, the petroleum ether extract-treated group showed significant differences in the levels of TNF-α (161.67±4.93, 106.33±3.21, 77.67±4.04 pg/mL) and IL-10 (291.77±4.93, 185.09±9.54, 141.33±1.53 pg/mL) on the 7th, 14th, and 21st days; a significant difference in the content of TGF-β1 (75.68±3.06 pg/mL) on the 21st day; and a significant difference in the level of VEGF (266.67±4.73, 311.33±10.50 pg/mL) on the 7th and 14th days respectively.

CONCLUSION

Petroleum ether Nanocnide lobata extract and the volatile oil compounds of Nanocnide lobata might be effective drugs in the treatment of burn and scald injuries, as they exhibited a protective effect on burns and scalds by reducing the expression of TNF-α, IL-10 and TGF-β1 and increasing the expression of VEGF. In addition, these compounds may also exert pharmacological effects that promote wound tissue repair, accelerate wound healing, and reduce scar tissue proliferation, inflammation and pain.

Bacterial cellulose membrane incorporated with silver nanoparticles for wound healing in animal model

The bacterial cellulose membrane (CM) is a promising biomaterial due to its easy applicability and moist environment. Moreover, nanoscale silver compounds (AgNO₃) are synthesized and incorporated into CMs to provide these biomaterials with antimicrobial activity for wound healing. This study aimed to evaluate the cell viability of CM incorporated with nanoscale silver compounds, determine the minimum inhibitory concentration (MIC) for Escherichia coli and Staphylococcus aureus, and its use on in vivo skin lesions. Wistar rats were divided according to treatment: untreated, CM (cellulose membrane), and AgCM (CM incorporated with silver nanoparticles). The euthanasia was performed on the 2nd, 7th, 14th, and 21st days to assess inflammation (myeloperoxidase-neutrophils, N-acetylglucosaminidase-macrophage, IL-1β, IL-10), oxidative stress (NO-nitric oxide, DCF-H₂O₂), oxidative damage (carbonyl: membrane's damage; sulfhydryl: membrane's integrity), antioxidants (superoxide dismutase; glutathione), angiogenesis, tissue formation (collagen, TGF-β1, smooth muscle α-actin, small decorin, and biglycan proteoglycans). The use of AgCM did not show toxicity, but antibacterial effect in vitro. Moreover, in vivo, AgCM provided balanced oxidative action, modulated the inflammatory profile due to the reduction of IL-1β level and increase in IL-10 level, in addition to increased angiogenesis and collagen formation. The results suggest the use of silver nanoparticles (AgCM) enhanced the CM properties by providing antibacterial properties, modulation the inflammatory phase, and consequently promotes the healing of skin lesions, which can be used clinically to treat injuries.

Expression of Interleukin-1β and Histological Changes of the Three-Dimensional Oral Mucosal Model in Response to Yttria-Stabilized Nanozirconia

Over the years, advancement in ceramic-based dental restorative materials has led to the development of monolithic zirconia with increased translucency. The monolithic zirconia fabricated from nano-sized zirconia powders is shown to be superior in physical properties and more translucent for anterior dental restorations. Most in vitro studies on monolithic zirconia have focused mainly on the effect of surface treatment or the wear of the material, while the nanotoxicity of this material is yet to be explored. Hence, this research aimed to assess the biocompatibility of yttria-stabilized nanozirconia (3-YZP) on the three-dimensional oral mucosal models (3D-OMM). The 3D-OMMs were constructed using human gingival fibroblast (HGF) and immortalized human oral keratinocyte cell line (OKF6/TERT-2), co-cultured on an acellular dermal matrix. On day 12, the tissue models were exposed to 3-YZP (test) and inCoris TZI (IC) (reference material). The growth media were collected at 24 and 48 h of exposure to materials and assessed for IL-1β released. The 3D-OMMs were fixed with 10% formalin for the histopathological assessments. The concentration of the IL-1β was not statistically different between the two materials for 24 and 48 h of exposure (p = 0.892). Histologically, stratification of epithelial cells was formed without evidence of cytotoxic damage and the epithelial thickness measured was the same for all model tissues. The excellent biocompatibility of nanozirconia, as evidenced by the multiple endpoint analyses of the 3D-OMM, may indicate the potential of its clinical application as a restorative material.

F. Alotaibi M, Nasrullah MZ, Alrabia MW, Asfour HZ, Abdel-Naim AB. Cordycepin- Melittin nanoconjugate intensifies wound healing efficacy in diabetic rats

The current study was designed to develop a nanoconjugate of cordycepin-melittin (COR-MEL) and assess its healing property in wounded diabetic rats. The prepared nanoconjugate has a particle size of 253.5 ± 17.4 nm with a polydispersity index (PDI) of 0.35 ± 0.04 and zeta potential of 17.2 ± 0.3 mV. To establish the wound healing property of the COR-MEL nanoconjugate, animal studies were pursued, where the animals with diabetes were exposed to excision and treated with COR hydrogel, MEL hydrogel, or COR-MEL nanoconjugate topically. The study demonstrated an accelerated wound contraction in COR-MEL nanoconjugate -treated diabetic rats, which was further validated by histological analysis. The nanoconjugate further exhibited antioxidant activities by inhibiting the accumulation of malondialdehyde (MDA) and exhaustion of superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic activities. The nanoconjugate further demonstrated an enhanced anti-inflammatory activity by retarding the expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Additionally, the nanoconjugate exhibits a strong expression of transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF)-A, and platelet-derived growth factor (PDGFR)-β, indicating enrichment of proliferation. Likewise, nanoconjugate increased the concentration of hydroxyproline as well as the mRNA expression of collagen, type I, alpha 1 (Col 1A1). Thus, it is concluded that the nanoconjugate possesses a potent wound-healing activity in diabetic rats via antioxidant, anti-inflammatory, and pro-angiogenetic mechanisms.

In vitro and in vivo synergistic wound healing and anti-methicillin-resistant Staphylococcus aureus (MRSA) evaluation of liquorice-decorated silver nanoparticles

The multi-drug resistant Staph. aureus strain, Methicillin-resistant Staphylococcus aureus (MRSA), is an emerging pathogen that could penetrate skin cuts and wounds, causing a life-threatening condition. The green biosynthesis of silver nanoparticles with liquorice extract has been demonstrated over several years for anticancer and antioxidant effects, as well as antibacterial effect against both Gram-positive and Gram-negative bacteria. The study was designed to evaluate the synergistic in vivo and in vitro wound healing and anti-MRSA activity of decorated liquorice silver nanoparticles (LD-AgNPs). The LD-AgNPs were prepared by thoroughly mixing diluted liquorice extract with AgNO₃ at room temperature. The prepared nanoparticles were characterized by size measurement, IR spectroscopy, TEM imaging, and X-ray diffraction. The in vitro and in vivo antibacterial and wound healing testing were also performed. The obtained LD-AgNPs were spherical in shape and had a hydrodynamic size of about 50.16 ± 5.37 nm. Moreover, they showed potent antibacterial activity against Gram-positive and Gram-negative resistant bacteria, produced a significantly higher level of procollagen type I compared to either liquorice extract or standard silver sulfadiazine, and promoted the wound healing process in rabbits. The formulation of silver nanoparticles with liquorice extract showed synergetic effects in enhancing the treatment of wounds, with significant antibacterial activity against E. coli and MRSA.

An Updated Review of Hypertrophic Scarring

Hypertrophic scarring (HTS) is an aberrant form of wound healing that is associated with excessive deposition of extracellular matrix and connective tissue at the site of injury. In this review article, we provide an overview of normal (acute) wound healing phases (hemostasis, inflammation, proliferation, and remodeling). We next discuss the dysregulated and/or impaired mechanisms in wound healing phases that are associated with HTS development. We next discuss the animal models of HTS and their limitations, and review the current and emerging treatments of HTS.

Dipotassium Glycyrrhizininate Improves Skin Wound Healing by Modulating Inflammatory Process

Wound healing is characterized by a systemic and complex process of cellular and molecular activities. Dipotassium Glycyrrhizinate (DPG), a side product derived from glycyrrhizic acid, has several biological effects, such as being antiallergic, antioxidant, antibacterial, antiviral, gastroprotective, antitumoral, and anti-inflammatory. This study aimed to evaluate the anti-inflammatory effect of topical DPG on the healing of cutaneous wounds by secondary intention in an in vivo experimental model. Twenty-four male Wistar rats were used in the experiment, and were randomly divided into six groups of four. Circular excisions were performed and topically treated for 14 days after wound induction. Macroscopic and histopathological analyses were performed. Gene expression was evaluated by real-time qPCR. Our results showed that treatment with DPG caused a decrease in the inflammatory exudate as well as an absence of active hyperemia. Increases in granulation tissue, tissue reepithelization, and total collagen were also observed. Furthermore, DPG treatment reduced the expression of pro-inflammatory cytokines (Tnf-α, Cox-2, Il-8, Irak-2, Nf-kB, and Il-1) while increasing the expression of Il-10, demonstrating anti-inflammatory effects across all three treatment periods. Based on our results, we conclude that DPG attenuates the inflammatory process by promoting skin wound healing through the modulation of distinct mechanisms and signaling pathways, including anti-inflammatory ones. This involves modulation of the expression of pro- and anti-inflammatory cytokine expression; promotion of new granulation tissue; angiogenesis; and tissue re-epithelialization, all of which contribute to tissue remodeling.

Acute Inflammation in Tissue Healing

There are well-established links between acute inflammation and successful tissue repair across evolution. Innate immune reactions contribute significantly to pathogen clearance and activation of subsequent reparative events. A network of molecular and cellular regulators supports antimicrobial and tissue repair functions throughout the healing process. A delicate balance must be achieved between protection and the potential for collateral tissue damage associated with overt inflammation. In this review, we summarize the contributions of key cellular and molecular components to the acute inflammatory process and the effective and timely transition toward activation of tissue repair mechanisms. We further discuss how the disruption of inflammatory responses ultimately results in chronic non-healing injuries.

Polypharmacological Cell-Penetrating Peptides from Venomous Marine Animals Based on Immunomodulating, Antimicrobial, and Anticancer Properties

Complex pathological diseases, such as cancer, infection, and Alzheimer's, need to be targeted by multipronged curative. Various omics technologies, with a high rate of data generation, demand artificial intelligence to translate these data into druggable targets. In this study, 82 marine venomous animal species were retrieved, and 3505 cryptic cell-penetrating peptides (CPPs) were identified in their toxins. A total of 279 safe peptides were further analyzed for antimicrobial, anticancer, and immunomodulatory characteristics. Protease-resistant CPPs with endosomal-escape ability in Hydrophis hardwickii, nuclear-localizing peptides in Scorpaena plumieri, and mitochondrial-targeting peptides from Synanceia horrida were suitable for compartmental drug delivery. A broad-spectrum S. horrida-derived antimicrobial peptide with a high binding-affinity to bacterial membranes was an antigen-presenting cell (APC) stimulator that primes cytokine release and naïve T-cell maturation simultaneously. While antibiofilm and wound-healing peptides were detected in Synanceia verrucosa, APC epitopes as universal adjuvants for antiviral vaccination were in Pterois volitans and Conus monile. Conus pennaceus-derived anticancer peptides showed antiangiogenic and IL-2-inducing properties with moderate BBB-permeation and were defined to be a tumor-homing peptide (THP) with the ability to inhibit programmed death ligand-1 (PDL-1). Isoforms of RGD-containing peptides with innate antiangiogenic characteristics were in Conus tessulatus for tumor targeting. Inhibitors of neuropilin-1 in C. pennaceus are proposed for imaging probes or therapeutic delivery. A Conus betulinus cryptic peptide, with BBB-permeation, mitochondrial-targeting, and antioxidant capacity, was a stimulator of anti-inflammatory cytokines and non-inducer of proinflammation proposed for Alzheimer's. Conclusively, we have considered the dynamic interaction of cells, their microenvironment, and proportional-orchestrating-host- immune pathways by multi-target-directed CPPs resembling single-molecule polypharmacology. This strategy might fill the therapeutic gap in complex resistant disorders and increase the candidates' clinical-translation chance.

A transient photoactivation of epidermal stem cells by femtosecond laser promotes skin wound healing

Wound healing is a long-term complex process, in which epidermal stem cells (EPSCs) in epidermis of skin have been found to play an essential role in it. We develop a noninvasive method to activate EPSCs in skin in vivo to promote wound healing, based on a microscopic system to enable a sequential frame-by-frame scanning of a femtosecond laser at 800 nm to the predefined skin region for a single time for 16 seconds. The laser is tightly focused on a submicron spot and localized in the epidermis, and scans point by point to activate EPSCs there. The density and stemness of EPSCs are significantly enhanced for at least 60 hours after the single-time transient photoactivation. We demonstrate this method works in a skin wound mouse model. Our results provide an optical method for in vivo EPSC activation and hold good potential in wound healing.

Wound Healing and Antioxidant Properties of Launaea procumbens Supported by Metabolomic Profiling and Molecular Docking

Wounds adversely affect people’s quality of life and have psychological, social, and economic impacts. Herbal remedies of Launaea procumbens (LP) are used to treat wounds. In an excision wound model, topical application of LP significantly promoted wound closure (on day 14, LP-treated animals had the highest percentages of wound closure in comparison with the other groups, as the wound was entirely closed with a closure percentage of 100%, p < 0.05). Histological analysis revealed a considerable rise in the number of fibroblasts, the amount of collagen, and its cross-linking in LP-treated wounds. Gene expression patterns showed significant elevation of TGF-β levels (2.1-fold change after 7 days treatment and 2.7-fold change in 14 days treatment) and downregulation of the inflammatory TNF-α and IL-1β levels in LP-treated wounds. Regarding in vitro antioxidant activity, LP extract significantly diminished the formation of H2O2 radical (IC50 = 171.6 μg/mL) and scavenged the superoxide radical (IC50 of 286.7 µg/mL), indicating antioxidant potential in a dose-dependent manner. Dereplication of the secondary metabolites using LC-HRMS resulted in the annotation of 16 metabolites. The identified compounds were docked against important wound-healing targets, including vascular endothelial growth factor (VEGF), collagen α-1, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and transforming growth factor-β (TGF-β). Among dereplicated compounds, luteolin 8-C-glucoside (orientin) demonstrated binding potential to four investigated targets (VEGF, interleukin 1β, TNF-α, and collagen α-1). To conclude, Launaea procumbens extract could be regarded as a promising topical therapy to promote wound healing in excisional wounds, and luteolin 8-C-glucoside (orientin), one of its constituents, is a potential wound-healing drug lead.

Quantitative assessment of platelet rich fibrin for the repair of extraction socket in a rat model

The present study evaluated the quantitative effects of platelet-rich fibrin (PRF) for the repair of extraction socket in Sprague Dawley (SD) rat model by assessing several key clinical parameters. Seventy two male SD rats were subjected to surgical extraction of the maxillary right incisor. Rats were randomly divided into four groups with eighteen rats in each group based on the treatment received: extraction socket without treatment of PRF was taken as control (group I). Extraction socket implanted with 0.1, 0.2, and 0.4 mL of PRF was taken as study groups (groups II, III, and IV). The obtained results demonstrated that, low dose of PRF efficiently enhanced the natural healing cascade. Whereas, high dose interfered with native tissue contribution and altered the natural healing process. The beneficial effects of quantity-based application of PRF may raise the possibility of a new approach as complementary therapy besides conventional treatment.

Mesoporous silica-coated silver nanoparticles as ciprofloxacin/siRNA carriers for accelerated infected wound healing

The colonization of bacterial pathogens is a major concern in wound infection and becoming a public health issue. Herein, a core–shell structured Ag@MSN (silver core embedded with mesoporous silica, AM)-based nanoplatform was elaborately fabricated to co-load ciprofloxacin (CFL) and tumor necrosis factor-α (TNF-α) small interfering RNA (siTNF-α) (AMPC@siTNF-α) for treating the bacterial-infected wound. The growth of bacterial pathogens was mostly inhibited by released silver ions (Ag⁺) and CFL from AMPC@siTNF-α. Meanwhile, the loaded siTNF-α was internalized by macrophage cells, which silenced the expression of TNF-α (a pro-inflammatory cytokine) in macrophage cells and accelerated the wound healing process by reducing inflammation response. In the in vivo wound model, the Escherichia coli (E. coli)-infected wound in mice almost completely disappeared after treatment with AMPC@siTNF-α, and no suppuration symptom was observed during the course of the treatment. Importantly, this nanoplatform had negligible side effects both in vitro and in vivo. Taken together, this study strongly demonstrates the promising potential of AMPC@siTNF-α as a synergistic therapeutic agent for clinical wound infections.

A Systematic Review of Keratinocyte Secretions: A Regenerative Perspective

Cell regenerative therapy is a modern solution for difficult-to-heal wounds. Keratinocytes, the most common cell type in the skin, are difficult to obtain without the creation of another wound. Stem cell differentiation towards keratinocytes is a challenging process, and it is difficult to reproduce in chemically defined media. Nevertheless, a co-culture of keratinocytes with stem cells usually achieves efficient differentiation. This systematic review aims to identify the secretions of normal human keratinocytes reported in the literature and correlate them with the differentiation process. An online search revealed 338 references, of which 100 met the selection criteria. A total of 80 different keratinocyte secretions were reported, which can be grouped mainly into cytokines, growth factors, and antimicrobial peptides. The growth-factor group mostly affects stem cell differentiation into keratinocytes, especially epidermal growth factor and members of the transforming growth factor family. Nevertheless, the reported secretions reflected the nature of the involved studies, as most of them focused on keratinocyte interaction with inflammation. This review highlights the secretory function of keratinocytes, as well as the need for intense investigation to characterize these secretions and evaluate their regenerative capacities.

Semaphorin 3A: A potential target for prevention and treatment of nickel allergy

Metal allergy is one of the typical immune disorders encountered during the application of dental/medical materials and has a highly complex pathogenic mechanism. Semaphorin 3A (Sema3A), a member of the semaphorin family, is reported to be involved in various immune disorders. However, its role in metal allergy has not been clarified yet. Herein, we show that Sema3A expression was upregulated in nickel (Ni) allergy-induced mouse ear tissue and in NiCl₂-stimulated mouse keratinocytes. Moreover, Sema3A regulated tumor necrosis factor-alpha production and mitogen-activated protein kinase activation in keratinocytes. The specific deletion of Sema3A in keratinocytes did not affect immune cell infiltration but reduced edema and ear swelling; it also impeded Th1 responses to cause a slight alleviation in Ni allergy in mice. Our results demonstrate that Sema3A promotes the development of metal allergy and should be explored as a potential target for the prevention and treatment of metal allergy.

Semaphorin 3A is upregulated in keratinocytes upon nickel exposure, subsequently promoting Th1 cytokine responses and driving nickel allergic reactions.

Features of cellular and molecular mechanisms of re-gulation of reparative processes in chronic wounds using photobiomodulation therapy

Introduction: Treatment of chronic wounds is an urgent worldwide problem for medicine. Among the many efforts in wound healing techniques, photobiomodulation therapy has shown promising results.

Aim: To study the effect of photobiomodulation therapy on optimisation of the regulation of reparative processes in chronic wounds by cytokines (through the example of interleukin-1β, tumour necrosis factor-alpha, interleukin-6, interleukin-4, interleukin-10, and granulocyte macrophage colony stimulating factor).

Materials and methods: The study involved 12 Wistar rats. A trophic wound was modelled in the animals. After the operation, the animals were divided into two groups of 6 animals each. The wound defects of animals in the experimental group were exposed to low-intensity laser radiation. Photobiomodulation therapy was applied once a day for 5 days, starting the day after wound modelling. The device Lika-therapist M (Ukraine) was used in a continuous mode at a wavelength of 660 nm, an output power of 50 mW, and an energy density of 1 J/cm², and 60 s exposure time.

Results: The study showed the following changes in the expression of intercellular mediators in the blood serum of animals with chronic wounds when using photobiomodulation therapy: a decrease in the levels of interleukin-1β (p&gt;0.05) and tumour necrosis factor-alpha (p&lt;0.05); increased concentrations of interleukin-4 (p&lt;0.05); the concentrations of interleukin-6, granulocyte macrophage colony stimulating factor, and interleukin-10 were not significantly changed. The histological study showed better organization of collagen fibers in the experimental group.

Conclusions: Photobiomodulation therapy can be an instrument for optimizing the reparative process by correcting the regulation by intercellular mediators.

Longitudinal in-vivo quantification of tumour microvascular heterogeneity by optical coherence angiography in pre-clinical radiation therapy

Stereotactic body radiotherapy (SBRT) is an emerging cancer treatment due to its logistical and potential therapeutic benefits as compared to conventional radiotherapy. However, its mechanism of action is yet to be fully understood, likely involving the ablation of tumour microvasculature by higher doses per fraction used in SBRT. In this study, we hypothesized that longitudinal imaging and quantification of the vascular architecture may elucidate the relationship between the microvasculature and tumour response kinetics. Pancreatic human tumour xenografts were thus irradiated with single doses of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$10$$\end{document}10, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$20$$\end{document}20 and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$30$$\end{document}30 Gy to simulate the first fraction of a SBRT protocol. Tumour microvascular changes were monitored with optical coherence angiography for up to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$8$$\end{document}8 weeks following irradiation. The temporal kinetics of two microvascular architectural metrics were studied as a function of time and dose: the diffusion-limited fraction, representing poorly vascularized tissue \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$>150$$\end{document}>150 μm from the nearest detected vessel, and the vascular distribution convexity index, a measure of vessel aggregation at short distances. These biological metrics allowed for dose dependent temporal evaluation of tissue (re)vascularization and vessel aggregation after radiotherapy, showing promise for determining the SBRT dose–response relationship.

Multiwalled carbon nanotubes functionalized bacterial cellulose as an efficient healing material for diabetic wounds

The unique pool of features makes bacterial cellulose (BC) a robust platform to tailor its functionalities. Herein, the BC matrix was reinforced with multiwalled carbon nanotubes (MWCNT) to control infection and accelerate the healing process of diabetic wounds. The prepared BC-MWCNT composite film was characterized and antibacterial activity was assessed. Further, the in-vivo wound healing activity was performed and temporal expression of interleukin (IL-1α), tumor necrosis factor (TNF-α), vascular endothelial growth factor (VEGF) and platelets derived growth factor (PDGF) was quantitatively measured by real-time PCR. The characterization results confirmed the reinforcement of the BC matrix with MWCNT. The composite film showed antibacterial activity against all the tested strains. Moreover, the macroscopic analysis of the wound demonstrated faster closure of the diabetic wound in BC-MWCNT group (99% healing) as compared to negative control (77%) in 21 days. Histological studies further supported the results where complete reepithelization of the epidermis and healthy granulation tissue were observed in BC-MWCNT treated group. Molecular studies revealed that BC-MWCNT group showed relatively lesser expression of pro-inflammatory cytokines IL-1α and TNF-α and higher expression of VEGF than control that may have favored the faster healing. This study suggested that the tailorable properties of BC can be exploited to develop composites with potential applications in diabetic wound healing.

One-Step Synthesis of Multifunctional Chitosan Hydrogel for Full-Thickness Wound Closure and Healing

Multifunctional hydrogel as a sealant or wound dressing with high adhesiveness and excellent antibacterial activity is highly desirable in clinical applications. In this contribution, one-step synthetic hydrogel based on quaternized chitosan (QCS), tannic acid (TA), and ferric iron (Fe(III)) is developed for skin incision closure and Staphylococcus aureus (S. aureus)-infected wound healing. In this hydrogel system, the ionic bonds and hydrogen bonds between QCS and TA form the main backbone of hydrogel, the metal coordination bonds between TA and Fe(III) (catechol-Fe) endow hydrogel with excellent adhesiveness and (near-infrared light) NIR-responsive photothermal property, and these multiple dynamic physical crosslinks enable QCS/TA/Fe hydrogel with flexible self-healing ability and injectability. Moreover, QCS/TA/Fe hydrogel possesses superior antioxidant, anti-inflammatory, hemostasis, and biocompatibility. Also, it is safe for vital organs. The data from the mouse skin incision model and infected full-thickness skin wound model presented the high wound closure effectiveness and acceleration of the wound healing process by this multifunctional hydrogel, highlighting its great potential in wound management.

Evolutionary conservation of leptin effects on wound healing in vertebrates: Implications for veterinary medicine

In mammals, the cytokine hormone leptin promotes wound healing by increasing inflammation, cellular recruitment, angiogenic regrowth, and re-epithelialization; however, it is not known whether leptin has conserved actions on wound healing in other vertebrates. Here, we tested the hypothesis that leptin promotes both the quality and speed of wound healing in the South African clawed frog, Xenopus laevis. First, fluorescent immunohistochemistry using a polyclonal antibody specific to Xenopus leptin showed that in juvenile dorsal skin, leptin protein is expressed in the dorsal epidermal layer, as well in blood vessel endothelial cells and sensory nerves that run along the base of the dermis. Injection of recombinant Xenopus leptin (rXleptin) stimulates phosphorylated STAT3 (pSTAT3), indicative of leptin-activated JAK/STAT signaling in the epidermis. Similar to mammals, leptin protein expression increases at the wound site after injury of the epidermis. We then cultured "punch-in-a-punch" full-thickness dorsal skin explants in three doses of rXleptin (0, 10, and 100 ng/ml) and showed that leptin treatment doubled the rate of wound closure after 48 h relative to skin punches cultured without leptin. Food restriction prior to wound explant culture reduced the amount of wound closure, but leptin injection prior to euthanasia rescued closure to similar control levels. Leptin treatment also significantly reduced bacterial infection of these epidermal punches by 48 h in culture. This study shows that leptin is likely an endogenous promoter of wound healing in amphibians. Leptin-based therapies have the potential to expedite healing and reduce the incidence of secondary infections without toxicity issues, the threat of antibiotic resistance, or environmental antibiotic contamination. The conservation of leptin's actions on wound healing also suggests that it may have similar veterinary applications for other exotic species.

Cationic, anionic and neutral polysaccharides for skin tissue engineering and wound healing applications

Today, chronic wound care and management can be regarded as a clinically critical issue. However, the limitations of current approaches for wound healing have encouraged researchers and physicians to develop more efficient alternative approaches. Advances in tissue engineering and regenerative medicine have resulted in the development of promising approaches that can accelerate wound healing and improve the skin regeneration rate and quality. The design and fabrication of scaffolds that can address the multifactorial nature of chronic wound occurrence and provide support for the healing process can be considered an important area requiring improvement. In this regard, polysaccharide-based scaffolds have distinctive properties such as biocompatibility, biodegradability, high water retention capacity and nontoxicity, making them ideal for wound healing applications. Their tunable structure and networked morphology could facilitate a number of functions, such as controlling their diffusion, maintaining wound moisture, absorbing a large amount of exudates and facilitating gas exchange. In this review, the wound healing process and the influential factors, structure and properties of carbohydrate polymers, physical and chemical crosslinking of polysaccharides, scaffold fabrication techniques, and the use of polysaccharide-based scaffolds in skin tissue engineering and wound healing applications are discussed.

Baby's skin bacteria: first impressions are long-lasting

Early life is a dynamic period for skin microbial colonization and immune development. We postulate that microbial exposures in this period durably alter the skin immune trajectory and later disease susceptibility. Bacteria contribute to infant skin immune imprinting via interactions with microbes as well as with cutaneous epithelial and immune cells. Excellent research is underway at the skin microbiome-immune interface, both in deciphering basic mechanisms and implementing their therapeutic applications. As emphasized herein, focusing on the unique opportunities and challenges presented by microbial immune modulation in early life will be important. In our view, only through dedicated study of skin-microbe crosstalk in this developmental window can we elucidate the molecular underpinnings of pivotal events that contribute to sustained host-microbe symbiosis.

The Dynamic Change of Gene-Regulated Networks in Cashmere Goat Skin with Seasonal Variation

The Cashmere goat (Capra hircus) is renowned for its high-quality fiber production trait. The hair cycle in Cashmere goat has an annual rhythm. To deepen the understanding of the molecular foundation of annual rhythm in the skin of Cashmere goat, we did a comparative analysis of the Cashmere goat skin transcriptome all year round. 4002 Differentially expressed genes (DEGs) were identified with seasonal variations. 12 months transcriptome were divided into four developmental stages: Jan-Mar, Apr-Jul, Aug-Oct, and Nov-Dec based on gene expression patterns. 13 modules of highly correlated genes in skin were identified using WGCNA. Ten of these modules were consistent with the development stages. The gene function of those genes in each module was analyzed by functional enrichment. The results indicated that Wnt and Hedgehog signaling pathways were inhibited from January to March and activated from April to July. The cutaneous immune system of Cashmere goats has high activity from August to October. Fatty acid metabolism dominates goat skin from November to December. This study provides new information related to the annual skin development cycle, which could provide molecular biological significance for understanding the seasonal development and response to the annual rhythm of skin.

Cutaneous Wound Healing: An Update from Physiopathology to Current Therapies

The skin is the biggest organ of human body which acts as a protective barrier against deleterious agents. When this barrier is damaged, the organism promotes the healing process with several molecular and cellular mechanisms, in order to restore the physiological structure of the skin. The physiological control of wound healing depends on the correct balance among its different mechanisms. Any disruption in the balance of these mechanisms can lead to problems and delay in wound healing. The impairment of wound healing is linked to underlying factors as well as aging, nutrition, hypoxia, stress, infections, drugs, genetics, and chronic diseases. Over the years, numerous studies have been conducted to discover the correct approach and best therapies for wound healing, including surgical procedures and non-surgical treatments such as topical formulations, dressings, or skin substitutes. Thus, this general approach is necessary to facilitate the direction of further studies. This work provides updated concepts of physiological mechanisms, the factors that can interfere, and updated treatments used in skin wound healing.

Skin Wound-Healing Potential of Polysaccharides from Medicinal Mushroom Auricularia auricula-judae (Bull.)

Auricularia auricula-judae, a nutrient-rich mushroom used in traditional medicine, is a macrofungi that exhibits various biological properties. In this study, we have reported on the mechanisms that promote the wound-healing effects of a water-soluble polysaccharide-rich extract obtained from A. auricula-judae (AAP). AAP contained high amounts of polysaccharides (349.83 ± 5.00 mg/g extract) with a molecular weight of 158 kDa. The main sugar composition of AAP includes mannose, galactose, and glucose. AAP displayed antioxidant activity in vitro and was able to abort UVB-induced intracellular ROS production in human fibroblasts in cellulo. AAP significantly promoted both fibroblast and keratinocyte proliferation, migration, and invasion, along with augmentation of the wound-healing process by increasing collagen synthesis and decreasing E-cadherin expression (All p < 0.05). Specifically, the AAP significantly accelerated the wound closure in a mice skin wound-healing model on day 9 (2.5%AAP, p = 0.031 vs. control) and day 12 (1% and 2.5%AAP with p = 0.009 and p < 0.001 vs. control, respectively). Overall, our results indicate that the wound-healing activities of AAP can be applied in an AAP-based product for wound management.

An Accelerated Wound-Healing Surgical Suture Engineered with an Extracellular Matrix

A suture is a ubiquitous medical device to hold wounded tissues together and support the healing process after surgery. Surgical sutures, having incomplete biocompatibility, often cause unwanted infections or serious secondary trauma to soft or fragile tissue. In this research, UV/ozone (UVO) irradiation or polystyrene sulfonate acid (PSS) dip-coating is used to achieve a fibronectin (FN)-coated absorbable suture system, in which the negatively charged moieties produced on the suture cause fibronectin to change from a soluble plasma form into a fibrous form, mimicking the actions of cellular fibronectin upon binding. The fibrous fibronectin coated on the suture can be exploited as an engineered interface to improve cellular migration and adhesion in the region around the wounded tissue while preventing the binding of infectious bacteria, thereby facilitating wound healing. Furthermore, the FN-coated suture is found to be associated with a lower friction between the suture and the wounded tissue, thus minimizing the occurrence of secondary wounds during surgery. It is believed that this surface modification can be universally applied to most kinds of sutures currently in use, implying that it may be a novel way to develop a highly effective and safer suture system for clinical applications.

Mathematical modelling, parameter estimation and computational simulation for skin wound healing under Copaiferalangsdorffi treatments

We present three mathematical models which simulate the wound healing time for 10% oil-resin (10% OR), 10% hydroalcoholic extract (10% EH) (Copaifera langsdorffii drugs), Lanette cream (LC) and Collagenase treatments. Wound healing is a complex process consisting of inflammatory, proliferative and remodelling phases. The experiments were made on rats with wounds on their backs. The mathematical models consider the interplay among neutrophils, macrophages, which play an essential role in skin wound healing, pro-inflammatory (IL-6) and anti-inflammatory (IL-10) cytokines. The ordinary differential equations (ODE) models reproduce the cellular dynamics of wound healing on the skin, suggesting levels of macrophages and neutrophils cellularity, consistent with the values of total cellularity obtained in the laboratory. The partial differential equations (PDE) model replicate the dispersion along the wound radius, suggesting that the balance of the interleukins is better modelled on copaíba-based treatments (CBT). The cell density is directly influenced by neutrophils in the wound bed and by macrophages at the wound edge. It was possible to find the time for wound healing for all treatments by inserting the diffusive terms.

Correlation Between Facial Skin Microbiota and Skin Barriers in a Chinese Female Population with Sensitive Skin

Background and Aim

The association of microbiota changes with sensitive skin remains controversial until now. Although a strong correlation is detected between skin microbiota distribution and biophysical parameters, there is little knowledge on the link between sensitive skin and skin microbiota in Chinese women. This study aimed to unravel the correlation between facial skin microbiota distribution and skin barriers in Chinese women with sensitive skin.

Materials and Methods

In total, 34 volunteers were enrolled, including 24 subjects with sensitive skin (SS group) and 10 subjects with non-sensitive skin (NS group). The cuticle moisture content, transepidermal water loss (TEWL), and facial skin sebum secretion were measured, and the facial skin surface morphology was evaluated. Sensitive skin samples were collected from the facial (SS-F group) and chest skin of subjects in the SS group (SS-C group), while non-sensitive skin samples were collected from the facial skin of subjects in the NS group (NS-F group). All skin samples were subjected to 16S rRNA sequencing.

Results

16S rRNA sequencing detected Actinobacteria, Firmicutes, and Proteobacteria as the three most common microbiota phyla and Propionibacterium, Paracoccus, and Corynebacterium as the three most common microbiota genera, and there were no significant differences in the relative frequency of Actinobacteria, Firmicutes, or Proteobacteria, or Propionibacterium, Paracoccus, or Corynebacterium among the SS-F, SS-C, and NS-F groups (P>0.05). We detected no significant difference in the diversity of bacterial communities among the SS-F, SS-C, and NS-F groups; however, the Shannon’s diversity index was significantly higher in the NS-F group than in the SS-C group. In addition, Spearman correlation analysis showed a correlation between the microbiota genera and skin physiological parameters (P<0.05).

Conclusion

This study preliminarily unravels the skin microbiota of sensitive skin using a high-throughput tool, and there are no microbiota genera with strong associations with skin physiological parameters.

What Is the Impact of Depletion of Immunoregulatory Genes on Wound Healing? A Systematic Review of Preclinical Evidence

Cytokines and growth factors are known to play an important role in the skin wound closure process; however, in knockout organisms, the levels of these molecules can undergo changes that result in the delay or acceleration of this process. Therefore, we systematically reviewed evidence from preclinical studies about the main immunoregulatory molecules involved in skin repair through the analysis of the main mechanisms involved in the depletion of immunoregulatory genes, and we carried out a critical analysis of the methodological quality of these studies. We searched biomedical databases, and only original studies were analyzed according to the PRISMA guidelines. The included studies were limited to those which used knockout animals and excision or incision wound models without intervention. A total of 27 studies were selected; data for animal models, gene depletion, wound characteristics, and immunoregulatory molecules were evaluated and compared whenever possible. Methodological quality assessments were examined using the ARRIVE and SYRCLE's bias of risk tool. In our review, the extracellular molecules act more negatively in the wound healing process when silenced and the metabolic pathway most affected involved in these processes was TGF-β/Smad, and emphasis was given to the importance of the participation of macrophages in TGF-β signaling. Besides that, proinflammatory molecules were more evaluated than anti-inflammatory ones, and the main molecules evaluated were, respectively, TGF-β1, followed by VEGF, IL-6, TNF-α, and IL-1β. Overall, most gene depletions delayed wound healing, negatively influenced the concentrations of proinflammatory cytokines, and consequently promoted a decrease of inflammatory cell infiltration, angiogenesis, and collagen deposition, compromising the formation of granulation tissue. The studies presented heterogeneous data and exhibited methodological limitations; therefore, mechanistic and highly controlled studies are required to improve the quality of the evidence.

Mushrooms-Rich Preparations on Wound Healing: From Nutritional to Medicinal Attributes

Mushrooms have a significant role in human diet as functional food and as a nutraceutical resource. The combination of its umami flavor, protein, vitamins, minerals and carbohydrates has meant that mushrooms could be considered a cheap food source for a long time in many countries. Moreover, mushrooms contain an excellent variety of bioactive metabolites that can be successful in both prevention and treatment of various human health hazards. In addition, extracts from medicinal mushrooms and their metabolites have been verified for wound treating with contribution to different mechanisms of the healing process. This review summarizes the nutritional value and composition of mushrooms, ethnobiology and ethnopharmacology, and wound healing potential.

Proinflammatory cytokines regulate epidermal stem cells in wound epithelialization

The skin, which serves as the first barrier of the human body, is particularly susceptible to exogenous injuries. Skin wounds, including acute burns and chronic non-healing ulcers, are commonly observed in clinics. Healing of skin wounds is a complex process, consisting of infiltration of inflammatory cells, cellular proliferation, and tissue remodeling phases, which restore the integrity and functions of the skin. Epithelialization is involved in wound healing through re-establishing an intact keratinocyte layer. Epidermal stem cells are indispensable for epithelialization, and they are regulated by multiple proinflammatory cytokines or growth factors. In this review, we summarize recent advances in the effect of these cytokines on migration, proliferation, and differentiation processes of epidermal stem cells. We also introduce promising therapeutic strategies targeting epidermal stem cells or related proinflammatory cytokines for patients with skin wounds.