Full-thickness Skin Research Articles

Unveiling the impact of hypodermis on gene expression for advancing bioprinted full-thickness 3D skin models

Unveiling the impact of hypodermis on gene expression for advancing bioprinted full-thickness 3D skin models

Morphological characteristics of wound healing with aloe extract, hydrogel, and their combination: experimental research

BACKGROUND: Currently, there remains a high incidence of skin damage due to trauma, chronic diseases, burns, so it is important to study the issues of regeneration and treatment of skin wounds. AIM: To conduct a morphological analysis of wound healing using aloe extract, hydrogel, and their combination in the experiment. MATERIALS AND METHODS: The study involved 40 sexually mature guinea pigs, which were divided into a control group and 4 experimental groups (independent wound healing, application of aloe extract, hydrosorb gel, layer-by-layer application of drugs). Histological skin preparations were prepared on days 3, 7, 14, and 28 of the experiment. In each microslide, in 10 fields of view of the microscope at a magnification of ×50, morphometric parameters were measured in micrometers (µm): the thickness of the purulent-necrotic scab, inflammatory (leukocyte) infiltrate, granulation tissue, the length of the newly formed epithelium on days 3, 7, 14; the thickness of the epithelium, its length and the thickness of the connective tissue in the central part of the regenerate on the 28th day. All data were subjected to statistical processing. RESULTS: The medications led to a decrease in the inflammatory reaction, acceleration of the formation of granulation tissue, and partial wound epithelization by day 7 of the experiment; however, more pronounced signs of wound healing were observed with layer-by-layer application of aloe extract and hydrogel. By day 14, regardless of the application method, the use of medications demonstrated signs of enhanced wound healing. Thus, the length of the epithelium increased by 1.2–1.6 times, the depth of granulation tissue increased by 1.0–1.2 times compared to the control group. By the end of the experiment, all animals had complete closure of the wound with scar formation, while in the experimental groups showed signs of skin remodeling with appendages. CONCLUSION: Morphological analysis showed that aloe extract, hydrosorb gel, and their combination accelerated the wound healing processes of full-thickness skin wounds in the experiment.

A photocurable and thermocurable composite hydrogel and the application in a contraction resistant full-thickness skin model

Abstract Three-dimensional (3D) organotypic skin in vitro has attracted increasing attention for drug development, cosmetics evaluation, and even clinical applications. However, the severe contraction of these models restricts their application, especially in the analyses based on barrier functions such as percutaneous penetration. For the full-thickness skin equivalents, the mechanical properties of the dermis scaffold plays an important role in the contraction resistance. In this investigation, we optimized a hydrogel composed of gelatine methacrylamide (GelMA), hyaluronic acid methacrylate (HAMA), and type I collagen (Col I), adjusted the elastic moduli to 2.27±0.08 kPa to fit the skin cells growth and resist contraction as well. This optimized hydrogel exhibited a swelling ratio of 23.25 ± 0.94% and demonstrated satisfactory cell viability in fibroblasts cultures. Then, we mixed this hydrogel with fibroblasts of liquid-liquid culture to construct the dermis, on which seeded keratinocytes were seeded for another 14 days of air-liquid culture to form cornified epidermis, and a commercialized hydrogel Ava-FT-Skin was used as control. This optimized skin model could maintained its integrity for a prolonged period of 28 days. Differentiated epidermis presented basal, spinous, granular, and cornified layers, meanwhile, epidermis markers like keratin-10, keratin-14, involucrin, loricrin, filaggrin, and dermis markers vimentin were expressed distinctly in the right distribution. Furthermore, penetration of a 607 Da Cascade blue-labelled dextran was calculated and compared to the Avatarget skin model, both of which could prevent more than 99% of the fluorescent molecule. We consider that this full-thickness skin model could be widely used in pharmaceutical and cosmetic industries, especially in penetration detection, contributing to the excellent contraction resistance.

Conventional Versus Regenerative Methods for Wound Healing: A Comparative Experimental Study on a Sheep Model

Background and Objectives: Wound healing is a complex process involving cellular, anatomical, and functional repair, often hindered in chronic wounds associated with diseases like diabetes and vascular disorders. This study investigated the efficacy of conventional and regenerative wound healing approaches in a sheep surgical wound model. Materials and Methods: Six female Bergamasca sheep underwent five full-thickness skin lesions treated with various methods: sterile gauze (control), chlorhexidine, sodium hypochlorite, micronized dermis system application, and dermal matrix. Wound healing progression was monitored over 42 days through wound dimension measurements, exudate analysis, and histopathological evaluations. Results: The results indicated that all wounds healed completely by day 42, with significant reductions in wound size and exudate over time. Notably, Micronized dermis system application and dermal matrix treatments showed a faster evolution in exudate characteristics and improved collagen reorganization compared to other treatments. Histological analysis revealed earlier neovascularization and better reconstitution of hair follicles in these groups. Despite the lack of significant differences in healing time, both regenerative approaches enhanced wound healing phases, contributing to exudate control, angiogenesis promotion, and reduced scar formation. Conclusions: The findings suggest that while micronized dermis system application and dermal matrix do not accelerate acute wound healing compared to conventional methods, they offer potential benefits in managing exudate and improving tissue regeneration, warranting further investigation in chronic wound scenarios.

Design of an Innovative Method for Measuring the Contractile Behavior of Engineered Tissues.

Hypertrophic scarring is a common complication in severely burned patients who undergo autologous skin grafting. Meshed skin grafts tend to contract during wound healing, increasing the risk of pathological scarring. Although various technologies have been used to study cellular contraction, current methods for measuring contractile forces at the tissue level are limited and do not replicate the complexity of native tissues. Self-assembled skin substitutes (SASSs) were developed at the "Centre de recherche en organogénèse expérimentale de l'Université Laval/LOEX" and are used as permanent full-thickness skin grafts. The autologous skin substitutes are produced using the self-assembly method, allowing the cultured cells to produce their extracellular matrix leading to a tissue-engineered substitute resembling the native skin. The level of contraction of the SASSs during the fabrication process is patient-dependent. Thus, because of its architecture and composition, SASS is an interesting model to study skin contraction in vitro. Unfortunately, standard measurement methods are unsuited for SASS contraction assessment, mainly due to incompatibilities between the SASS manufacturing process and the current contraction force measurement methods. Here, we present an innovative contraction measurement method specifically designed to quantify the contractile behavior of tissue-engineered substitutes, without disrupting the protocol of production. The method uses C-shape anchoring frames that close at different speeds and magnitudes according to the tissue contractile behavior. A finite element analysis model is then used to associate the frame deformation to a contractile force amplitude. This article shows that the method can be used to measure the contraction force of tissues produced with cells displaying different contractile properties, such as primary skin fibroblasts and myofibroblasts. It can also be used to study the effects of cell culture conditions on tissue contraction, such as serum concentration. This protocol can be easily and affordably applied and tuned to many regenerative medicine applications or contraction-related pathological studies. Impact Statement The protocol presented in this article is a new and simple method to quantify contraction forces present in tissue-engineered substitutes. Using finite element analysis, it allows for the measurement of a contraction force rather than a surface reduction as usually provided by other tissue contraction measurement methods. The results shown are in correlation with the current literature relevant to tissue contraction. It can be easily implemented, and hence, this method will open up new avenues to study tissue contraction of living substitutes engineered with various cell types and to optimize culture conditions.

Retention of nickel, cobalt and chromium in skin at conditions mimicking intense hand hygiene practices using water, soap, and hand-disinfectant in vitro

BackgroundDuring the COVID-19 pandemic, increased hand hygiene practices using water, soap and hand disinfectants, became prevalent, particularly among frontline workers. This study investigates the impact of these practices on the skin’s ability to retain the allergenic metals nickel, cobalt, and chromium. The study constitutes three parts: (I) creating an impaired skin barrier, (II) exposing treated and untreated skin to nickel alone, and (III) in co-exposure with cobalt and chromium.MethodsUsing full-thickness skin from stillborn piglets, in vitro experiments were conducted to assess retention of metals in skin at conditions mimicking intense hand hygiene practices. Treatment of skin with varying concentrations of sodium lauryl sulphate (SLS), to impair its barrier integrity was assessed. This was followed by exposure of treated and untreated skin to the metals, that were dissolved in Milli-Q water, 0.5% SLS, and ethanol respectively.ResultsResults showed that pre-treatment with 5% SLS impaired the skin barrier with regards to the measure of trans epidermal water loss (TEWL). Metal amounts retained in the skin were generally higher in treated than untreated skin. The highest amounts of metal retained in skin were observed for exposure to nickel in ethanol. Co-exposure to nickel, cobalt, and chromium in 0.5% SLS resulted in the highest amounts of total metal retention.ConclusionsThe in vitro findings highlight the increased risk of metal retention in skin due to an impaired barrier. The SLS concentration used in the current study corresponds to those used in many hand hygiene products. Hence, occupational settings with frequent exposure to water, soap and disinfectants need to consider protective measures not only for the irritant exposures themselves but also simultaneous exposure to allergenic metals.

Pickering Emulsion of Curcumin Stabilized by Cellulose Nanocrystals/Chitosan Oligosaccharide: Effect in Promoting Wound Healing

Background: The stabilization of droplets in Pickering emulsions using solid particles has garnered significant attention through various methods. Cellulose and chitin derivatives in nature offer a sustainable source of Pickering emulsion stabilizers. Methods: In this study, medium-chain triglycerides were used as the oil phase for the preparation of emulsion. This study explores the potential of cellulose nanocrystals (CNC) and shell oligosaccharides (COS) as effective stabilizers for achieving stable Pickering emulsions. Optical microscopy, CLSM, and Cyro-SEM were employed to analyze CNC/COS–Cur, revealing the formation of bright and uniform yellow spherical emulsions. Results: CLSM and SEM results confirmed that CNC/COS formed a continuous and compact shell at the oil–water interface layer, enabling a stable 2~3 microns Pickering emulsion with CNS/COS–Cur as an oil-in-water emulsion stabilizer. Based on FTIR, XRD, and SEM analyses of CNC/COS, along with zeta potential measurements of the emulsion, we found that CNC and COS complexed via electrostatic adsorption, forming irregular rods measuring approximately 200–300 nm in length. An evaluation of the DPPH radical-scavenging ability demonstrated that the CNC/ COS–Cur Pickering emulsion performed well in vitro. In vivo experiments involving full-thickness skin excision surgery in rats revealed that CNC/COS–Cur facilitated wound repair processes. Measurements of the MDA and SOD content in healing tissues indicated that the CNC/COS–Cur Pickering emulsion increased SOD levels and reduced MDA content, effectively countering oxidative stress-induced damage. An assessment based on wound-healing rates and histopathological examination showed that CNC/COS-Cur promoted granulation tissue formation, fibroblast proliferation, angiogenesis, and an accelerated re-epithelialization process within the wound tissue, leading to enhanced collagen deposition and facilitating rapid wound-healing capabilities. An antibacterial efficacy assessment conducted in vitro demonstrated antibacterial activity.

A systematic review of the Novosorb® Biodegradable Temporizing Matrix in the treatment of complex wounds

BackgroundRestoringafunctionaldermisfollowingextensive,deepwounds,suchasthosecausedbysevereburns,presentsasignificantreconstructivechallenge. Although split thickness skin graft (STSG) and full thickness skin graft (FTSG) can provide adequate coverage, dermal templates are becoming increasingly important in restoring function. The purpose of this systematic review is to assess the efficacy, advantages and limitations of employing NovoSorb® Biodegradable Temporizing Matrix (BTM) in the treatment of complex wounds. MethodsThe systematic review was carried out in accordance with PRISMA and MOOSE guidelines when appropriate. All studies until April 2024 involving patients treated with NovoSorb® BTM were considered. Infection,adverseevents,andBTMlosswereamongtheoutcomesevaluated. ResultsWe identified 725 studies, and 69 were included after screening. The included studies involved 880 participants and were mostly concerned with the management of burns, but other difficult wounds were also addressed. The infection rate was 10%, yet only few reported losing their BTM as a result of this consequence. The incidence of adverse events was low, with the majority of trials reporting no adverse events related to BTM. ConclusionOur systematic review focused primarily on case series and case reports that demonstrated the efficacy of Novosorp BTM and the rarity of side effects. However, there were very few comparison research. More research is needed to fully analyze the efficacy, limitations, and downsides of using Novosorb (BTM).

Rotating cell culture system-induced injectable self-assembled microtissues with epidermal stem cells for full-thickness skin repair.

Epidermal stem cells (EpSCs) are crucial for wound healing and tissue regeneration, and traditional culture methods often lead to their inactivation. It is urgent to increase the yield of high quality EpSCs. In this study, primary EpSCs were isolated and cultured in a serum-free, feeder-free culture system. EpSCs are then expanded in a dynamic 3D environment using a rotating cell culture system (RCCS) with biodegradable porous microcarriers (MC). Over a period of 14 days, the cells self-assembled into microtissues with superior cell proliferation compared to 3D static culture. Immunofluorescence and qPCR analyses consistently showed that the stemness of the 3D microtissues was preserved, especially the COL17A1 associated with anti-aging was highly expressed in RCCS induced microtissues. In vivo experiments demonstrated that the group treated with 3D microtissues loaded with EpSCs showed enhanced early wound healing, and the injectable 3D microtissues were more conducive to maintaining cell viability and differentiation potential. Our study provides valuable insights into the dynamic 3D culture of EpSCs and introduces an injectable therapy using 3D microtissues loaded with EpSCs, which provides a new and effective approach for cell delivery and offering a promising strategy for guiding the regeneration of full-thickness skin defects.

021. Outcomes of Adult Patients That Got Full Thickness Skin Graft with Skin Defects After the Surgical Wide Excision: Observational Case Series Study

Background: Full-thickness skin grafting plays an important role in reconstruction for excessive skin defects after the surgical wide excision. For closed defect consideration, full-thickness skin grafts can be used, The most common full-thickness skin graft donor sites include the retroauricular region, supraclavicular region, inguinal fold, buttock fold, hypothenar area, and anterior wrist fold. In this study. Methods: This is a single institutional, retrospective, observational case series study. We included 8 patients who underwent skin reconstruction using full-thickness skin grafts to close skin defects caused by the excision of skin tumor or trauma, between January 2024 and July 2024. Demographic data, including sex, age, location and photographs, and were collected. Results: the follow up for 8 patients that got full-thickness skin graft, we can make conclusion that full-thickness skin graft, can be the choice to closed the defect. The outcome of the patient is good with the defect is closed. Conclusion: Full-thickness skin grafting is a common technique for reconstructing skin defects after surgical wide excision. This case series demonstrates that using full-thickness grafts can effectively close these defects. Despite the challenges posed by the extent and location of the defects, the grafts provided a reliable solution when primary closure was not possible. Overall, this study highlights the importance of full-thickness skin grafting in the field of reconstructive surgery.

Spiny mice are primed but fail to regenerate volumetric skeletal muscle loss injuries

BackgroundIn recent years, the African spiny mouse Acomys cahirinus has been shown to regenerate a remarkable array of severe internal and external injuries in the absence of a fibrotic response, including the ability to regenerate full-thickness skin excisions, ear punches, severe kidney injuries, and complete transection of the spinal cord. While skeletal muscle is highly regenerative in adult mammals, Acomys displays superior muscle regeneration properties compared with standard laboratory mice following several injuries, including serial cardiotoxin injections of skeletal muscle and volumetric muscle loss (VML) of the panniculus carnosus muscle following full-thickness excision injuries. VML is an extreme muscle injury defined as the irrecoverable ablation of muscle mass, most commonly resulting from combat injuries or surgical debridement. Barriers to the treatment of VML injury include early and prolonged inflammatory responses that promote fibrotic repair and the loss of structural and mechanical cues that promote muscle regeneration. While the regeneration of the panniculus carnosus in Acomys is impressive, its direct relevance to the study of VML in patients is less clear as this muscle has largely been lost in humans, and, while striated, is not a true skeletal muscle. We therefore sought to test the ability of Acomys to regenerate a skeletal muscle more commonly used in VML injury models.MethodsWe performed two different VML injuries of the Acomys tibialis anterior muscle and compared the regenerative response to a standard laboratory mouse strain, Mus C57BL6/J.ResultsNeither Acomys nor Mus recovered lost muscle mass or myofiber number within three months following VML injury, and Acomys also failed to recover force production better than Mus. In contrast, Acomys continued to express eMHC within the injured area even three months following injury, whereas Mus ceased expressing eMHC less than one-month post-injury, suggesting that Acomys muscle was primed, but failed, to regenerate.ConclusionsWhile the panniculus carnosus muscle in Acomys regenerates following VML injury in the context of full-thickness skin excision, this regenerative ability does not translate to regenerative repair of a skeletal muscle.

Enhancing wound healing through innovative technologies: microneedle patches and iontophoresis

IntroductionWound healing is a complex process involving multiple stages, including inflammation, proliferation, and remodeling. Effective wound management strategies are essential for accelerating healing and improving outcomes. The CELLADEEP patch, incorporating iontophoresis therapy and microneedle technology, was evaluated for its potential to enhance the wound healing process.MethodsThis study utilized a full-thickness skin defect model in Sprague-Dawley rats, researchers compared wound healing outcomes between rats treated with the CELLADEEP Patch and those left untreated. Various histological staining techniques were employed to examine and assess the wound healing process, such as H&E, MT and immunofluorescence staining. Furthermore, the anti-inflammatory and proliferative capabilities were further investigated using biochemical assays.ResultsMacroscopic and microscopic analyses revealed that the CELLADEEP patch significantly accelerated wound closure, reduced wound width, and increased epidermal thickness and collagen deposition compared to an untreated group. The CELLADEEP patch decreased nitric oxide and reactive oxygen species levels, as well as pro-inflammatory cytokines IL-6 and TNF-α, indicating effective modulation of the inflammatory response. Immunofluorescence staining showed reduced markers of macrophage activity (CD68, F4/80, MCP-1) in the patch group, suggesting a controlled inflammation process. Increased levels of vimentin, α-SMA, VEGF, collagen I, and TGF-β1 were observed, indicating enhanced fibroblast activity, angiogenesis, and extracellular matrix production.DiscussionThe CELLADEEP patch demonstrated potential in promoting effective wound healing by accelerating wound closure, modulating the inflammatory response, and enhancing tissue proliferation and remodeling. The CELLADEEP patch offers a promising non-invasive treatment option for improving wound healing outcomes.

Effect of aspirin on platelet-rich plasma of diabetes mellitus with lower extremity atherosclerosis.

Aim: Platelet-rich plasma (PRP), enriched with multiple growth factors, is a promising adjunctive therapy for diabetic foot ulcers (DFUs). As a classic anti-platelet drug for diabetic patients, the effects of aspirin on the content of growth factors in PRP remains unclear.Methods: Our study enrolled diabetic patients who were currently taking or not taking aspirin as the research subjects, with healthy volunteers as the control. PRP from these individuals was activated with glucose calcium and thrombin. Growth factors levels in PRP activated supernatant (PRP-AS) and wound healing ability of platelet gel (PG) in the full-thickness skin defect diabetic mouse model were compared.Results: We found the level of growth factors in PRP-AS derived from two groups of diabetic patients were not statistically different, whereas both lower than that from healthy volunteers. Similarly, we found better wound healing ability of PG from healthy volunteers than those from diabetic patients, but no difference between the two groups of diabetic patients in the mouse model.Discussion: Aspirin does not interfere with autologous PRP therapy when using calcium gluconate and thrombin as agonists. However considering the content of growth factors, PRP from healthy volunteers is a preferable option for promoting DFU repair.

Construction and Performance Study of an Injectable Dual-Network Hydrogel Dressing with Inherent Drainage Function.

With the widespread utilization of moist wound dressings, the extended healing time and increased risk of wound infection caused by excessively moist environments have garnered significant attention. The development of hydrogel dressings that can effectively control the wound moisture level and promote healing is very important. Inspired by the pore-opening perspiration effect of the skin, this study constructed an injectable dual-network hydrogel, CMCS-OSA/AG/MXene, by the composition of a dynamic covalent network of carboxymethyl chitosan and oxidized sodium alginate based on the Schiff base and hydrogen bond network of the thermosensitive low-melting-point agar with the advantage of the upper critical solution temperature (UCST) effect. Under near-infrared (NIR) light stimulation, the CMCS-OSA/AG/MXene hydrogel shows characteristics conducive to rapid removal of wound exudate while maintaining an appropriate moist environment for the wound and excellent antibacterial effects with its photothermal responses. The excellent conductivity of the hydrogel can also promote cell proliferation under external electrical stimulation (ES). Further validation through animal experiments on a full-thickness skin defect model demonstrates the excellent capability of CMCS-OSA/AG/MXene in accelerating wound healing. This work provides an innovative approach to the development of injectable hydrogel dressing materials with inherent drainage functionality and shows a new avenue to wound moisture control and wound healing promotion.

Comparative Retrospective Analysis of Cross-Finger Flap Outcomes: A Study on Split-Thickness Skin Graft vs. Full-Thickness Skin Graft in Donor Fingers

Comparative Retrospective Analysis of Cross-Finger Flap Outcomes: A Study on Split-Thickness Skin Graft vs. Full-Thickness Skin Graft in Donor Fingers

Lactobacillus rhamnosus GG-derived extracellular vesicles promote wound healing via miR-21-5p-mediated re-epithelization and angiogenesis

Extracellular vesicles (EVs), especially those derived from stem cells, have emerged as a novel treatment for promoting wound healing in regenerative medicine. However, the clinical application of mammalian cells-derived EVs is hindered by their high cost and low yields. Inspired by the ability of EVs to mediate interkingdom communication, we explored the therapeutic potential of EVs released by the probiotic strain Lactobacillus rhamnosus GG (LGG) in skin wound healing and elucidated the underlying mechanism involved. Using full-thickness skin wound-healing mouse models, we found that LGG-EVs accelerated wound healing procedures, including increased re-epithelialization and promoted angiogenesis. Using in vitro experiments, we further demonstrated that LGG-EVs boosted the proliferation and migration capacities of both epithelial and endothelial cells, as well as promoted endothelial tube formation. miRNA profiling analysis revealed that miR-21-5p was highly enriched in LGG-EVs and LGG-EV treatment significantly increased miR-21-5p level in recipient cells. Mechanically, LGG-EVs induced regulatory effects via miR-21-5p mediated metabolic signaling rewiring. Our results suggest that EVs derived from LGG could serve as a promising candidate for accelerating wound healing and possibly for treating chronic and impaired healing conditions.Graphical abstract

Dandelion-shaped strontium-gallium microparticles for the hierarchical stimulation and comprehensive regulation of wound healing

Abstract The management of full-thickness skin injuries continues to pose significant challenges. Currently, there is a dearth of comprehensive dressings capable of integrating all stages of wound healing to spatiotemporally regulate biological processes following full-thickness skin injuries. In this study, we report the synthesis of a dandelion-shaped mesoporous strontium-gallium microparticle (GE@SrTPP) achieved through dopamine-mediated strontium ion biomineralization and self-assembly, followed by functionalization with gallium metal polyphenol networks (MPNs). As CroCfunctional wound dressing, GE@SrTPP can release bioactive ions in a spatiotemporal manner akin to dandelion seeds. During the early stages of wound healing, GE@SrTPP demonstrates rapid and effective hemostatic performance while also exhibiting antibacterial properties. In the inflammatory phase, GE@SrTPP promotes M2 polarization of macrophages, suppresses the expression of pro-inflammatory factors, and decreases oxidative stress in wounds. Subsequently, during the stages of proliferation and tissue remodeling, GE@SrTPP facilitates angiogenesis through the activation of the HIF-1α/VEGF pathway. Analogous to the dispersion and rooting of dandelion seeds, the root-like new blood vessels supply essential nutrients for wound healing. Ultimately, in a rat chronic wound model, GE@SrTPP achieved successful full-thickness wounds repair. In summary, these dandelion-shaped GE@SrTPP microparticles demonstrate comprehensive regulatory effects in managing full-thickness wounds, making them highly promising materials for clinical applications.

Designing injectable dermal matrix hydrogel combined with silver nanoparticles for methicillin-resistant Staphylococcus aureus infected wounds healing

Hydrogel-based delivery systems have now emerged as a pivotal platform for addressing chronic tissue defects, leveraging their innate capacity to suppress pathogenic infections and facilitate expedited tissue regeneration. In this work, an injectable hydrogel dressing, termed AgNPs-dermal matrix hydrogel (Ag@ADMH), has been designed to expedite the healing process of wounds afflicted with methicillin-resistant Staphylococcus aureus (MRSA), featuring sustained antibacterial efficacy. The synthesis of the hydrogel dressing entailed a self-assembly process of collagen fibers within an acellular dermal matrix to construct a three-dimensional scaffold, encapsulated with plant polyphenol-functionalized silver nanoparticles (AgNPs). The Ag@ADMH demonstrated exceptional biocompatibility, and enables a sustained release of AgNPs, ensuring prolonged antimicrobial activity. Moreover, the in vitro RT-qPCR analysis revealed that compared with ADMH, Ag@ADMH diminish the expression of iNOS while augmenting CD206 expression, thereby mitigating the inflammatory response and fostering wound healing. Especially, the Ag@ADMH facilitated a reduction in M1 macrophage polarization, as evidenced by a significant decrement in the M1 polarization trend and an enhanced M2/M1 ratio in dermal matrix hydrogels laden with AgNPs, corroborated by confocal microscopy and flow cytometry analyses of macrophage phenotypes. The in vivo assessments indicated that Ag@ADMH minimized fibrous capsule formation. In a full-thickness skin defect model of MRSA infection, the formulation significantly attenuated the inflammatory response by reducing MPO and CD68 expression levels, concurrently promoting collagen synthesis and CD34 expression, pivotal for vasculogenesis, thereby accelerating the resolution of MRSA-infected wounds. These attributes underscore the injectable extracellular matrix hydrogel as a formidable strategy for the remediation and regeneration of infected wounds.Graphical

Photobiomodulation on Full-Thickness Skin Graft Survivalin Rats.

To evaluate the photobiomodulation effects on the receptor area for full-thickness skin graft integration. Thirty-Six Wistar rats were divided: red laser (660 nm), infrared laser (808 nm), and control. A skin segment with 5 × 3 cm was removed. In the control, the skin was reallocated after a 180° rotation. For the 660 nm and 808 nm, the receptor area was first irradiated, and then the skin was reallocated the same as the control. Euthanasia occurred on the third and seventh days after the procedure, and macroscopical of necrosis and histological analysis were realized. The 660 nm reached the lowest necrosis percentage on Day 7. In the 808 nm, necrosis increased between the two periods. Similar morphological findings were observed for the control and 660 nm; however, the 808 nm showed significant alterations in fibrosis and inflammatory infiltrate. The infrared wavelength showed inferior performance on skin graft integration compared to the control and the red wavelength.

Combination therapy of placenta-derived mesenchymal stem cells and artificial dermal scaffold promotes full-thickness skin defects vascularization in rat animal model

PurposeRecently, placenta-derived mesenchymal stem cells (PMSCs) have garnered considerable attention in tissue repair and regeneration. The present study was conducted to evaluate the effect of PMSCs on artificial dermal scaffold (ADS) angiogenesis and their combination therapy on wound closure. Material and methodsHerein, the growth and survival of PMSCs in ADS were explored. CCK8, scratch wound, and tubule formation assays were employed to investigate the effects of ADS conditioned medium (CM) and ADS-PMSCs CM on human umbilical vein endothelial cells (HUVECs). The effect of ADS-PMSCs on full-thickness skin defects healing was evaluated based on a rat model. Wound healing progresses was meticulously investigated through hematoxylin and eosin (HE), Masson’s trichrome, and immunohistochemical staining analyses. ResultsIn vitro cell culture results demonstrated the proliferation of PMSCs in ADS. The ADS-PMSCs CM notably stimulated the proliferation, migration, and tube formation of HUVECs compared to the ADS CM group. In the rat full-thickness skin defect model, the ADS-PMSCs treatment significantly accelerated the vascularization area of ADS after 2 weeks. Besides, HE and Masson’s trichrome staining results indicated that ADS-PMSCs treatment significantly enhanced fibroblast proliferation and collagen fiber 2 weeks after surgical procedure. Compared to the ADS group, collagen fiber arrangement was thicker in the ADS-PMSCs group. Immunohistochemical staining reinforced this finding, illustrating a substantial increase in CD31 expression within the ADS-PMSCs group. ConclusionsThe results suggest that the combination of ADS with PMSCs accelerates ADS vascularization by fostering granulation tissue development and boosting the formation of new blood vessels.