CD80 on skin stem cells promotes local expansion of regulatory T cells upon injury to orchestrate repair within an inflammatory environment.

Following tissue damage, epithelial stem cells (SCs) are mobilized to enter the wound, where they confront harsh inflammatory environments that can impede their ability to repair the injury. Here, we investigated the mechanisms that protect skin SCs within this inflammatory environment. Characterization of gene expression profiles of hair follicle SCs (HFSCs) that migrated into the wound site revealed activation of an immune-modulatory program, including expression of CD80, major histocompatibility complex class II (MHCII), and CXC motif chemokine ligand 5 (CXCL5). Deletion of CD80 in HFSCs impaired re-epithelialization, reduced accumulation of peripherally generated Treg (pTreg) cells, and increased infiltration of neutrophils in wounded skin. Importantly, similar wound healing defects were also observed in mice lacking pTreg cells. Our findings suggest that upon skin injury, HFSCs establish a temporary protective network by promoting local expansion of Treg cells, thereby enabling re-epithelialization while still kindling inflammation outside this niche until the barrier is restored.

Stem Cell Lineage Infidelity Drives Wound Repair and Cancer.

Tissue stem cells contribute to tissue regeneration and wound repair through cellular programs that can be hijacked by cancer cells. Here, we investigate such a phenomenon in skin, where during homeostasis, stem cells of the epidermis and hair follicle fuel their respective tissues. We find that breakdown of stem cell lineage confinement-granting privileges associated with both fates-is not only hallmark but also functional in cancer development. We show that lineage plasticity is critical in wound repair, where it operates transiently to redirect fates. Investigating mechanism, we discover that irrespective of cellular origin, lineage infidelity occurs in wounding when stress-responsive enhancers become activated and override homeostatic enhancers that govern lineage specificity. In cancer, stress-responsive transcription factor levels rise, causing lineage commanders to reach excess. When lineage and stress factors collaborate, they activate oncogenic enhancers that distinguish cancers from wounds.

The role of fibronectin in mediating cell migration.

Fibronectin (FN) is a major extracellular matrix (ECM) protein involved in a wide range of physiological processes, including cell migration. These FN-mediated cell migration events are essential to processes such as wound repair, cancer metastasis, and vertebrate development. This review synthesizes mainly current literature to provide an overview of the mechanoregulatory role of FN-mediated cell migration. Background on FN structure and role in mechanotransduction is provided. Cell migration concepts are introduced, including the general cell migration mechanism and classification of cell migration types. Then, FN-mediated events that directly affect cell migration are explored. Finally, a focus on FN in tissue repair and cancer migration is presented, as these topics represent a large amount of current research.

Self-Assembled DNA Composite-Engineered Mesenchymal Stem Cells for Improved Skin-Wound Repair.

The direct use of mesenchymal stem cells (MSCs) as therapeutics for skin injuries is a promising approach, yet it still faces several obstacles, including limited adhesion, retention, and engraftment of stem cells in the wound area, as well as impaired regenerative and healing functions. Here, DNA-based self-assembled composites are reported that can aid the adhesion of MSCs in skin wounds, enhance MSC viability, and accelerate wound closure and re-epithelialization. Rolling-circle amplification (RCA)-derived DNA flowers, equipped with multiple copies of cyclic Arg-Gly-Asp (cRGD) peptides and anti-von Willebrand factor (vWF) aptamers, act as robust scavengers of reactive oxygen species (ROS) and enable synergistic recognition and adhesion to stem cells and damaged vascular endothelial cells. These DNA structure-aided stem cells are retained at localized wound sites, maintain repair function, and promote angiogenesis and growth factor secretion. In both normal and diabetes-prone db/db mice models with excisional skin injuries, facile topical administration of DNA flower-MSCs elicits rapid blood vessel formation and enhances the sealing of the wound edges in a single dose. DNA composite-engineered stem cells warrant further exploration as a new strategy for the treatment of skin and tissue damage.

Prussian Blue-Assisted NIR Triggered In-Situ Polymerized Nanocomposite Hydrogel for Wound Repair.

Hydrogels are commonly used as wound dressings to help maintain a moist environment around the wound and isolate contaminants, thus promoting healing. For irregular wounds, the slow healing process and even infection may occur due to the inability of dressings to adhere well to the wound. Prussian blue (PB) is a metal-organic framework (MOF) material with excellent photothermal conversion and superior stability. In this paper, a kind of near-infrared (NIR) light triggered in-situ polymerized antimicrobial hydrogel was prepared. The free radical initiator was encapsulated in the hollow PB by a phase change material (PCM) to maintain stability. The raised temperature triggered by NIR induced the release and decomposition of the initiator. The matrix was formed by the cross-linking of double bonds on modified chitosan. The quaternary amine groups of modified chitosan and the photothermal properties of PB enhanced the antimicrobial properties of the hydrogel. High-quality wound healing was demonstrated in the whole skin defect model. This study provides a new reference for the preparation of in-situ polymerized hydrogel dressings for irregular wounds.

An evaluation of the usability and durability of 3D printed versus standard suture materials.

The capability to produce suture material using three-dimensional (3D) printing technology may have applications in remote health facilities where rapid restocking of supplies is not an option. This is a feasibility study evaluating the usability of 3D-printed sutures in the repair of a laceration wound when compared with standard suture material. The 3D-printed suture material was manufactured using a fused deposition modelling 3D printer and nylon 3D printing filament. Study participants were tasked with performing laceration repairs on the pigs' feet, first with 3-0 WeGo nylon suture material, followed by the 3D-printed nylon suture material. Twenty-six participants were enrolled in the study. Survey data demonstrated statistical significance with how well the 3D suture material performed with knot tying, 8.9 versus 7.5 (p = 0.0018). Statistical significance was observed in the 3D-printed suture's ultimate tensile strength when compared to the 3-0 Novafil suture (274.8 vs. 199.8 MPa, p = 0.0096). The 3D-printed suture also demonstrated statistical significance in ultimate extension when compared to commercial 3-0 WeGo nylon suture (49% vs. 37%, p = 0.0215). This study was successful in using 3D printing technology to manufacture suture material and provided insight into its usability when compared to standard suture material.

Altering CO2 Laser Pulse Energy Settings Did Not Influence Differential Gene Transcription in Normal Skin in a Red Duroc Pig Model.

OBJECTIVES: Fractional ablative CO2 lasers are used clinically to treat cutaneous burn scars with reported varying degrees of effectiveness. It was hypothesized that different laser pulse energy settings may lead to differential gene transcription in a porcine model. METHODS: Uninjured skin from red Duroc pigs was treated with a fractional ablative CO2 laser set to 70, 100, or 120 mJ across the abdomen (n = 4 areas per treatment). Punch biopsies of both treated and untreated sites were taken before treatment (baseline), at 30 min, and at each hour for 6 h and stored in All-Protect tissue reagent. The biopsies were then used to isolate RNA, which was subsequently used in qRT-PCR for eight genes associated with wound healing and the extracellular matrix: CCL2, IL6, FGF2, TIMP1, TIMP3, COL1A2, MMP2, and DCN. RPL13a was used as a housekeeping gene to normalize the eight genes of interest. One-way ANOVA tests were used to assess for differences among laser pulse energies and two-way ANOVA tests were used to assess the differences between treated and untreated areas. RESULTS: While six of the eight genes were upregulated after treatment (p < 0.05), there were no significant differences in gene expression between the different laser pulse energies for any of the eight genes. CONCLUSION: While laser treatment is correlated with a positive and significant upregulation for six of the eight genes 4 h after intervention, the pulse energy settings of the laser did not lead to a statistically significant difference in gene transcription among the treatment areas. Different laser pulse energies may not be required to induce similar cellular responses in a clinical setting.

Performance of multiple therapeutic approaches for palatal wound healing after soft tissue graft removal - an overview of systematic reviews.

OBJECTIVE: To overview the literature to answer the following question: "What is the performance of different therapies on wound healing and postoperative discomfort after palatal ASTG removal?" METHODS: SRs that evaluated the wound healing (WH), postoperative pain, bleeding, and analgesic consumption of patients submitted to de-epithelialized/free gingival grafts (FGG) or subepithelial connective tissue grafts (SCTG) removed from the palate were included. The searches were conducted on six white and two gray databases up to December 2023. Methodological quality was evaluated through AMSTAR 2. The synthesis of results was described as a narrative analysis. RESULTS: Ten SRs (involving 25 randomized clinical trials) related to low-level laser therapy (LLLT) (3), platelet-rich fibrin (PRF) (4), cyanoacrylate tissue adhesives (CTA) (2), and ozone therapy (OT) (1) were included in this overview. All techniques demonstrated improvements in WH. LLT, PRF, and CTA reduced pain and analgesic consumption. PRF and CTA reduced bleeding. Regarding methodological quality, the SRs were classified as critically low (2), low (5), moderate (2), or high quality (1). CONCLUSIONS: In SRs related to LLLT, PRF, CTA, and OT, the use of different therapies after palatal ASTG removal improved WH and postoperative discomfort. Due to the studies' low methodological quality and high heterogeneity, data should be interpreted with caution. CLINICAL RELEVANCE: The present overview compiles the evidence of SRs related to different therapies for WH and patients' postoperative experience and reveals that different treatments can significantly improve the clinical outcomes of patients who require ASTG removal for periodontal or peri-implant surgeries. REGISTRATION: PROSPERO registration number: CRD42022301257.

Artificial dermis combined with negative pressure wound therapy and platelet-rich plasma to treat traumatic wounds: a retrospective study.

OBJECTIVE: The reconstruction of complex soft tissue defects with exposure of bones and tendons represents an increasing challenge in wound care, especially in large extremity wounds. The aim of this study was to detect the clinical efficacy of combined use of negative pressure wound therapy (NPWT), artificial dermis (ADM), platelet-rich plasma (PRP) and split-thickness skin grafting (STSG) in the reconstruction of large traumatic extremity skin defects. METHOD: In this study, eight cases were treated with combined therapies for repairing complex extremity wounds and the results were reviewed retrospectively. After surgical debridement, all wounds received ADM, PRP and delayed STSG, which were all aided with NPWT. RESULTS: The patients consisted of five males and three females, with a mean age of 44 years. A total of six lower extremity wounds were located at the foot/ankle, with exposed tendon in five, bone exposure in three and both in two. Of the group, two patients had exposed tendon on arm/hand wounds. The size of wounds and ADM averaged 126cm2 and 42.3cm2, respectively. ADM was used to cover the exposed bone or tendon, the granulation and muscular tissue were covered with vacuum sealing drainage (VSD) directly, for NPWT. The survival rate of ADM averaged 98.9%. The average time for survival of ADM was 12.8 days and the mean uptake of autologous skin graft was 93.5%. Only one patient received repeated skin grafts. All patients achieved successful healing and reported no complications. The mean length of hospital stay was 36.1 days. CONCLUSION: Our study revealed that ADM in conjunction with NPWT, PRP and STSG could be used for repairing large traumatic extremity wounds. Wound closure was achieved without flaps, the aesthetic and functional outcomes were acceptable, and only one patient developed a 35% loss of skin graft. DECLARATION OF INTEREST: This work was supported by grants from the Natural Science Foundation of Hubei Province (grant no. 2020CFB464) and Youth Foundation of Wuhan Municipal Health Commission (grant no. WX20Q15). The authors have no conflicts of interest to declare.

Sprayable hydroxypropyl chitin/collagen extract of Ampelopsis brevipedunculata hydrogel accelerates wound healing.

OBJECTIVE: Keeping a wound moist can allow effective and rapid healing, and it can control the formation of scabs, thereby allowing cell proliferation and epithelial formation. When regularly changing a dressing, thermosensitive hydrogel as a moist dressing does not cause a secondary wound from adhesion. The main aim of this study was to evaluate the effect of a new sprayable thermosensitive hydrogel on wound healing. METHOD: The hydrophobic N-acetyl group of chitin was removed by microwave reaction with lye until the degree of acetylation was 60%, followed by reaction with propylene oxide to obtain hydroxypropyl chitin (HPCH) with a degree of substitution of 40%. After mixing HPCH with fish scale collagen (FSC), a thermosensitive hydrogel with a gel temperature of 26.5°C was obtained. Ampelopsis brevipedunculata extracts (ABE), which have been found to accelerate wound repair and improve healing, were added. HPCH/FSC is not toxic to the mouse L929 cell line and forms a hydrogel at body surface temperature. It can be easily sprayed on a wound. The HPCH/FSC has a three-dimensional network porous structure with a swelling ratio of 10.95:1 and a water vapour transmission rate of 2386.03±228.87g/m2/day; it can facilitate the penetration of water and air, and promote absorption of wound exudate. Wound repair was performed on five Sprague-Dawley rats. Each rat had three wounds, which were treated with medical gauze, HPCH/FSC and HPCH/FSC/ABE, respectively. RESULTS: The wounds in the HPCH/FSC/ABE group recovered the fastest in vivo, the mature wound site was smoother, the re-epithelialisation was even and thicker, and the angiogenesis developed rapidly to the mature stage. CONCLUSION: In this study, HPCH/FSC/ABE thermosensitive hydrogel was shown to effectively accelerate wound healing and was convenient for practical application.

Cellular In Vitro Responses Induced by Human Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles Obtained from Suspension Culture.

Mesenchymal stem/stromal cells (MSCs) and their extracellular vesicles (MSC-EVs) have been described to have important roles in tissue regeneration, including tissue repair, control of inflammation, enhancing angiogenesis, and regulating extracellular matrix remodeling. MSC-EVs have many advantages for use in regeneration therapies such as facility for dosage, histocompatibility, and low immunogenicity, thus possessing a lower possibility of rejection. In this work, we address the potential activity of MSC-EVs isolated from adipose-derived MSCs (ADMSC-EVs) cultured on cross-linked dextran microcarriers, applied to test the scalability and reproducibility of EV production. Isolated ADMSC-EVs were added into cultured human dermal fibroblasts (NHDF-1), keratinocytes (HaCat), endothelial cells (HUVEC), and THP-1 cell-derived macrophages to evaluate cellular responses (i.e., cell proliferation, cell migration, angiogenesis induction, and macrophage phenotype-switching). ADMSC viability and phenotype were assessed during cell culture and isolated ADMSC-EVs were monitored by nanotracking particle analysis, electron microscopy, and immunophenotyping. We observed an enhancement of HaCat proliferation; NHDF-1 and HaCat migration; endothelial tube formation on HUVEC; and the expression of inflammatory cytokines in THP-1-derived macrophages. The increased expression of TGF-ß and IL-1ß was observed in M1 macrophages treated with higher doses of ADMSC-EVs. Hence, EVs from microcarrier-cultivated ADMSCs are shown to modulate cell behavior, being able to induce skin tissue related cells to migrate and proliferate as well as stimulate angiogenesis and cause balance between pro- and anti-inflammatory responses in macrophages. Based on these findings, we suggest that the isolation of EVs from ADMSC suspension cultures makes it possible to induce in vitro cellular responses of interest and obtain sufficient particle numbers for the development of in vivo concept tests for tissue regeneration studies.

Natural agents as wound-healing promoters.

The management of acute and chronic wounds resulting from diverse injuries poses a significant challenge to clinical practices and healthcare providers. Wound healing is a complex biological process driven by a natural physiological response. This process involves four distinct phases, namely hemostasis, inflammation, proliferation, and remodeling. Despite numerous investigations on wound healing and wound dressing materials, complications still persist, necessitating more efficacious therapies. Wound-healing materials can be categorized into natural and synthetic groups. The current study aims to provide a comprehensive review of highly active natural animal and herbal agents as wound-healing promoters. To this end, we present an overview of in vitro, in vivo, and clinical studies that led to the discovery of potential therapeutic agents for wound healing. We further elucidated the effects of natural materials on various pharmacological pathways of wound healing. The results of previous investigations suggest that natural agents hold great promise as viable and accessible products for the treatment of diverse wound types.

Comparison of the effects of platelet-rich plasma and platelet-rich fibrin on the healing process of a rat's mucosal wound.

Due to the problems associated with the use of PRP, a platelet concentrates without coagulation factors, called platelet-rich fibrin (PRF), has been developed that, in addition to tissue regeneration and wound healing, contains more white blood cells (WBCs), which are important in the wound healing process. In this study, the effect of these two platelet-rich plasmas on the thickness of the epithelium, the number of blood vessels and fibroblasts, and wound area were measured in two groups of PRP and PRF and at different periods. We divided the rats into three groups: the control group, the group receiving PRP, and the group receiving PRF. The results showed a significant difference in the number of fibroblasts, wound area, thickness of epithelium, and number of vessels in all three groups. Based on the results, the use of PRP and PRF in wounds can accelerate the formation of epithelium, create better and more blood vessels, create a platform for the migration and formation of fibroblast cells, and facilitate faster wound closure. Also, comparing PRP and PRF, it can be concluded that, finally, PRF acts better than PRP in epithelialization.

Clinical application of V-shaped folded submental flap in the repair of oral defect. / Våž‹æŠ˜å é¢ä¸‹çš®ç“£ä¿®å¤å£è ”ç¼ºæŸçš„ä¸´åºŠåº”ç”¨.

OBJECTIVES: The repair of small and medium-sized defects in the oral has always been a challenge, free skin flap and distal pedicled tissue flaps are difficult to meet clinical needs, and the traditional under-chin flap has the risk of donor-area injury. This study aims to investigate the efficacy of V-shaped folded submental flap in the repair of small-sized and medium-sized oral defects. METHODS: The clinical data of 28 patients with oral defect lesions, who were hospitalized in the Department of Stomatology, Third Xiangya Hospital of Central South University from March 2019 to December 2022, were retrospectively analyzed. Patients were divided into a V-shaped folded group (17 cases) and a conventional group (11 cases) according to different surgical methods. The V-shaped folded group was treated with a V-shaped folded submental flap for postoperative soft tissue repair, while the conventional group was treated with a conventional submental flap for repair. The postoperative follow-up time was 6-48 months. The survival status, repair time, and repair effect of the 2 groups were compared. RESULTS: There was no significant difference in flap survival rate, flap size, flap preparation time, repair surgery time, and postoperative hospital stay between the 2 groups (all P>0.05). At 6 months after the surgery, the V-shaped folded group had no difficulty in raising the head or everting the lower lip, no "cat ear" deformity in the submental skin. Scars in the V-shaped folding group were hidden at the lower edge of the mandible. The wound aesthetics and functional scores in the V-shaped folded group were significantly higher than those in the conventional group (both P<0.05). CONCLUSIONS: The V-shaped foldable submental flap has the advantages of flexible design, simple preparation, reliable blood supply, and protection of the donor area, which can effectively protect the appearance of the chin and avoid functional disorders.

Electroacupuncture promotes skin wound repair by improving lipid metabolism and inhibiting ferroptosis.

Lipid metabolism plays an important role in the repair of skin wounds. Studies have shown that acupuncture is very effective in skin wound repair. However, there is little knowledge about the mechanism of electroacupuncture. Thirty-six SD rats were divided into three groups: sham-operated group, model group and electroacupuncture group, with 12 rats in each group. After the intervention, local skin tissues were collected for lipid metabolomics analysis, wound perfusion and ferroptosis-related indexes were detected and finally the effect of electroacupuncture on skin wound repair was comprehensively evaluated by combining wound healing rate and histology. Lipid metabolomics analysis revealed 37 differential metabolites shared by the three groups, mainly phospholipids, lysophospholipids, glycerides, acylcarnitine, sphingolipids and fatty acids, and they could be back-regulated after electroacupuncture. The recovery of blood perfusion and wound healing was faster in the electroacupuncture group than in the model group (p < 0.05). The levels of GPX4, FTH1, SOD and GSH-PX, which are related to ferroptosis, were higher in the electroacupuncture group than in the model group (p < 0.05). The levels of ACSL4 and MDA were lower in the electroacupuncture group than in the model group (p < 0.05). Electroacupuncture may promote skin wound repair by improving lipid metabolism and inhibiting ferroptosis in local tissues.

Serum lipidomics-based study of electroacupuncture for skin wound repair in rats.

Lipid metabolism plays an important role in the repair of skin wounds. Studies have shown that acupuncture is very effective in skin wound repair. However, there is little knowledge about the mechanism of electroacupuncture. Thirty-six SD rats were divided into three groups: sham-operated group, model group and electroacupuncture group, with six rats in each group. After the intervention, orbital venous blood was collected for lipid metabolomics analysis, wound perfusion was detected and finally the effect of electroacupuncture on skin wound repair was comprehensively evaluated by combining wound healing rate and histology. Lipid metabolomics analysis revealed 11 differential metabolites in the model versus sham-operated group. There were 115 differential metabolites in the model versus electro-acupuncture group. 117 differential metabolites in the electro-acupuncture versus sham-operated group. There were two differential metabolites common to all three groups. Mainly cholesteryl esters and sphingolipids were elevated after electroacupuncture and triglycerides were largely decreased after electroacupuncture. The electroacupuncture group recovered faster than the model group in terms of blood perfusion and wound healing (p < 0.05). Electroacupuncture may promote rat skin wound repair by improving lipid metabolism and improving local perfusion.

Wound repair in sea urchin larvae involves pigment cells and blastocoelar cells.

Sea urchin larvae spend weeks to months feeding on plankton prior to metamorphosis. When handled in the laboratory they are easily injured, suggesting that in the plankton they are injured with some frequency. Fortunately, larval wounds are repaired through an efficient wound response with mesenchymal pigment cells and blastocoelar cells assisting as the epithelium closes. An injury to the epithelium leads to an immediate calcium transient that rapidly spreads around the entire larva and is necessary for activating pigment cell migration toward the wound. If calcium transport is blocked, the pigment cells fail to activate and remain in place. When activated, pigment cells initiate directed migration to the wound site from distances of at least 85 â€‹µm. Upon arrival at the wound site they participate in an innate immune response. Blastocoelar cells are recruited to the injury site as well, though the calcium transient is unnecessary for activating these cells. At the wound site, blastocoelar cells participate in several functions including remodeling the skeleton if it protrudes through the epithelium.

A coherent feed-forward loop drives vascular regeneration in damaged aerial organs of plants growing in a normal developmental context.

Aerial organs of plants, being highly prone to local injuries, require tissue restoration to ensure their survival. However, knowledge of the underlying mechanism is sparse. In this study, we mimicked natural injuries in growing leaves and stems to study the reunion between mechanically disconnected tissues. We show that PLETHORA (PLT) and AINTEGUMENTA (ANT) genes, which encode stem cell-promoting factors, are activated and contribute to vascular regeneration in response to these injuries. PLT proteins bind to and activate the CUC2 promoter. PLT proteins and CUC2 regulate the transcription of the local auxin biosynthesis gene YUC4 in a coherent feed-forward loop, and this process is necessary to drive vascular regeneration. In the absence of this PLT-mediated regeneration response, leaf ground tissue cells can neither acquire the early vascular identity marker ATHB8, nor properly polarise auxin transporters to specify new venation paths. The PLT-CUC2 module is required for vascular regeneration, but is dispensable for midvein formation in leaves. We reveal the mechanisms of vascular regeneration in plants and distinguish between the wound-repair ability of the tissue and its formation during normal development.

Eph signaling is regulated by miRNA-210: Implications for corneal epithelial repair.

A distinct boundary exists between the progenitor cells in the basal limbal epithelium and the more differentiated corneal epithelial basal cells. We have shown that reciprocal expression patterns of EphA2 and Ephrin-A1 are likely to contribute to normal limbal-corneal epithelial compartmentalization as well as play a role in response to injury. How this signaling axis is regulated remains unclear. We have demonstrated that microRNAs (miRNAs) play critical roles in corneal epithelial wound healing and several miRNAs (e.g. miR-210) have been predicted to target ephrins. Previous expression profiling experiments demonstrated that miR-210 is prominently expressed in corneal epithelial cells. RNA-seq data acquired from miR-210-depleted HCECs showed up-regulation of genes involved in cellular migration. In addition, miR-210 is decreased after corneal injury while EphA2 is increased. Moreover, antago-210-treated HCECs markedly enhanced wound closure in a scratch wound assay. Antago-210 treatment resulted in increased EphA2 protein levels as well as pS897-EphA2, the pro-migratory form of EphA2. As expected, Ephrin-A1 levels were reduced, while levels of a well-known target of miR-210, Ephrin-A3, were increased by antago-210 treatment. The increase in migration with antago-210 could be inhibited by Ephrin-A1 overexpression, Ephrin-A1-Fc treatment or siRNA depletion of EphA2. However, depletion of Ephrin-A3 did not have effects on the antago-210-induced increase in migration. In addition, Ephrin-A1 overexpression and siEphA2 dampened EGFR signaling, which is increased by antago-210. Our data clearly demonstrate a link between miR-210 and EphA2/Ephrin-A1 signaling that regulates, in part, corneal epithelial migration. This interaction might potentially control the limbal-corneal epithelial boundary.

Protecting human amnion and chorion matrices during processing: Performance enhancement in a diabetic mouse model and human co-culture system.

Recent evidence suggests that protecting human amnion and chorion matrices (HACM) during processing enhances the performance of HACM for wound repair and tissue regeneration. We utilised a diabetic (db/db) delayed wound healing mouse model. Treatment of db/db full-thickness excisional wounds with HACM, processed with a polyampholyte preservative accentuated the proliferative phase of wound healing that decreased the time necessary to heal wounds. Polyampholyte protection improved the preservation of growth factors and cytokines during room temperature storage following E-beam sterilisation and improved its function in wound healing applications. Our findings indicate protected HACM tissue up-regulated MIP2, NF-kB, TNF-α, KI-67, and Arg1 (0.6-fold to 1.5-fold) but those changes were not statistically significant. Immunofluorescent assessment identifying cell activity illustrated an induction of the proliferative phase of wound healing and a switch from an inflammatory macrophage phenotype (M1) to a pro-regenerative macrophage phenotype (M2a). Genomic profiling of 282 genes was performed using Nanostring from co-cultures of human macrophages and fibroblasts. The polyampholyte + HACM-treated group, compared with the HACM or polyampholyte alone groups, had a statistically significant up-regulation (32-368 fold) of 12 genes primarily involved in macrophage plasticity including CLC7, CD209, CD36, HSD11B1, ICAM1, IL1RN, IL3RA, ITGAX, LSP1, and PLXDC2 (adj. p-value < 0.05). The polyampholyte alone group demonstrated statistically significant down-regulation of four genes ADRA2, COL7A1, CSF3, and PTGS2 (adj. p < 0.05). The HACM alone group up-regulated four genes ATG14, CXCL11, DNMT3A, and THBD, but the results were not statistically significant. Biomechanical measurements indicated that wounds treated with polyampholyte-protected HACM had more tensile integrity compared with wounds treated with HACM alone. These findings indicate that better protection of HACM during processing stabilises the HACM matrix, which may lead to improved wound healing outcomes.