CXCR4 antagonist delivery on decellularized skin scaffold facilitates impaired wound healing in diabetic mice by increasing expression of SDF-1 and enhancing migration of CXCR4-positive cells

Dissolvable microneedle-based wound dressing transdermally and continuously delivers anti-inflammatory and pro-angiogenic exosomes for diabetic wound treatment

Due to overactive inflammation and hindered angiogenesis, self-healing of diabetic wounds (DW) remains challenging in the clinic. Platelet-derived exosomes (PLT-Exos), a novel exosome capable of anti-inflammation and pro-angiogenesis, show great potential in DW treatment. However, previous administration of exosomes into skin wounds is topical daub or intradermal injection, which cannot intradermally deliver PLT-Exos into the dermis layer, thus impeding its long-term efficacy in anti-inflammation and pro-angiogenesis. Herein, a dissolvable microneedle-based wound dressing (PLT-Exos@ADMMA-MN) was developed for transdermal and long-term delivery of PLT-Exos. Firstly, a photo-crosslinking methacrylated acellular dermal matrix-based hydrogel (ADMMA-GEL), showing physiochemical tailorability, fast-gelling performance, excellent biocompatibility, and pro-angiogenic capacities, was synthesized as a base material of our dressing. For endowing the dressing with anti-inflammation and pro-angiogenesis, PLT-Exos were encapsulated into ADMMA-GEL with a minimum effective concentration determined by our in-vitro experiments. Then, in-vitro results show that this dressing exhibits excellent properties in anti-inflammation and pro-angiogenesis. Lastly, in-vivo experiments showed that this dressing could continuously and transdermally deliver PLT-Exos into skin wounds to switch local macrophage into M2 phenotype while stimulating neovascularization, thus proving a low-inflammatory and pro-angiogenic microenvironment for DW healing. Collectively, this study provides a novel wound dressing capable of suppressing inflammation and stimulating vascularization for DW treatment.

Critical signaling molecules in the temporomandibular joint osteoarthritis under different magnitudes of mechanical stimulation

The mechanical stress environment in the temporomandibular joint (TMJ) is constantly changing due to daily mandibular movements. Therefore, TMJ tissues, such as condylar cartilage, the synovial membrane and discs, are influenced by different magnitudes of mechanical stimulation. Moderate mechanical stimulation is beneficial for maintaining homeostasis, whereas abnormal mechanical stimulation leads to degeneration and ultimately contributes to the development of temporomandibular joint osteoarthritis (TMJOA), which involves changes in critical signaling molecules. Under abnormal mechanical stimulation, compensatory molecules may prevent degenerative changes while decompensatory molecules aggravate. In this review, we summarize the critical signaling molecules that are stimulated by moderate or abnormal mechanical loading in TMJ tissues, mainly in condylar cartilage. Furthermore, we classify abnormal mechanical stimulation-induced molecules into compensatory or decompensatory molecules. Our aim is to understand the pathophysiological mechanism of TMJ dysfunction more deeply in the ever-changing mechanical environment, and then provide new ideas for discovering effective diagnostic and therapeutic targets in TMJOA.

Laminin mimetic angiogenic and collagen peptide hydrogel for enhance dermal wound healing

Laminins are essential in basement membrane architecture and critical in re-epithelialization and angiogenesis. These processes and collagen deposition are vital in skin wound healing. The role of angiogenic peptides in accelerating the wound-healing process has been known. The bioactive peptides could be a potential approach due to their similar effects as growth factors and inherent biocompatible and biodegradable nature with lower cost. They can also recognize ligand-receptor interaction and mimic the extracellular matrix. Here, we report novel angiogenic DYVRLAI, CDYVRLAI, angiogenic-collagen PGPIKVAV, and Ac-PGPIKVAV peptides conjugated sodium carboxymethyl cellulose hydrogel, which was designed from laminin. The designed peptide exhibits a better binding with the α3β1, αvβ3, and α5β1 integrins and CXCR2 receptor, indicating their angiogenic and collagen binding efficiency. The peptides were evaluated to stimulate wound healing in full-thickness excision wounds in normal and diabetic mice (type II). They demonstrated their efficacy in terms of angiogenesis (CD31), re-epithelialization through regeneration of the epidermis (H&E), and collagen deposition (MT). The synthesized peptide hydrogel (DYVRLAI and CDYVRLAI) showed enhanced wound contraction up to 10.1 % and 12.3 % on day 7th compared to standard becaplermin gel (49 %) in a normal wound model. The encouraging results were also observed with the diabetic model, where these peptides showed a significant decrease of 5.20 and 5.17 % in wound size on day 10th compared to the commercial gel (9.27 %). These outcomes signify that the modified angiogenic peptide is a cost effective, novel peptide motif to promote dermal wound healing in both models.

Evolutionarily conserved mechanisms regulating stress-induced neutrophil redistribution in fish

Introduction

Stress may pose a serious challenge to immune homeostasis. Stress however also may prepare the immune system for challenges such as wounding or infection, which are likely to happen during a fight or flight stress response.

Methods

In common carp (Cyprinus carpio L.) we studied the stress-induced redistribution of neutrophils into circulation, and the expression of genes encoding CXC chemokines known to be involved in the regulation of neutrophil retention (CXCL12) and redistribution (CXCL8), and their receptors (CXCR4 and CXCR1-2, respectively) in blood leukocytes and in the fish hematopoietic organ - the head kidney. The potential involvement of CXC receptors and stress hormone receptors in stress-induced neutrophil redistribution was determined by an in vivo study with selective CXCR inhibitors and antagonists of the receptors involved in stress regulation: glucocorticoid/mineralocorticoid receptors (GRs/MRs), adrenergic receptors (ADRs) and the melanocortin 2 receptor (MC2R).

Results

The stress-induced increase of blood neutrophils was accompanied by a neutrophil decrease in the hematopoietic organs. This increase was cortisol-induced and GR-dependent. Moreover, stress upregulated the expression of genes encoding CXCL12 and CXCL8 chemokines, their receptors, and the receptor for granulocytes colony-stimulation factor (GCSFR) and matrix metalloproteinase 9 (MMP9). Blocking of the CXCR4 and CXCR1 and 2 receptors with selective inhibitors inhibited the stress-induced neutrophil redistribution and affected the expression of genes encoding CXC chemokines and CXCRs as well as GCSFR and MMP9.

Discussion

Our data demonstrate that acute stress leads to the mobilization of the immune system, characterized by neutrophilia. CXC chemokines and CXC receptors are involved in this stress-induced redistribution of neutrophils from the hematopoietic tissue into the peripheral blood. This phenomenon is directly regulated by interactions between cortisol and the GR/MR. Considering the pivotal importance of neutrophilic granulocytes in the first line of defense, this knowledge is important for aquaculture, but will also contribute to the mechanisms involved in the stress-induced perturbation in neutrophil redistribution as often observed in clinical practice.

Triazolothiadiazine derivative positively modulates CXCR4 signaling and improves diabetic wound healing

Development of specific therapies that target and accelerate diabetic wound repair is an urgent need to alleviate pain and suffering and the huge socioeconomic burden of this debilitating disease. C-X-C Motif Chemokine Ligand 12 (CXCL12) also know an stromal cell-derived factor 1α (SDF-1α) is a chemokine that binds the CXC chemokine receptor type 4 (CXCR4) and activates downstream signaling resulting in recruitment of hematopoietic cells to locations of tissue injury and promotes tissue repair. In diabetes, low expression of CXCL12 correlates with impaired wound healing. Activation of CXCR4 receptor signaling with agonists or positive allosteric modulators (PAMs) provides a potential for small molecule therapeutic discovery and development. We recently reported high throughput screening and identification of the CXCR4 partial agonist UCUF-728, characterization of in vitro activity and reduced wound closure time in diabetic mice at 100 μM as a proof-of-concept study. We report here, the discovery of a second chemical scaffold demonstrating increased agonist potency and represented by thiadiazine derivative, UCUF-965. UCUF-965 is a potent partial agonist of β-arrestin recruitment in CXCR4 receptor overexpressing cell line. Furthermore, UCUF-965 potentiates the CXCL12 maximal response in cAMP signaling pathway, activates CXCL12 stimulated migration in lymphoblast cells and modulates the levels of specific microRNA involved in the complex wound repair process, specifically in mouse fibroblasts. Our results indicate that UCUF-965 acts as a PAM agonist of the CXCR4 receptor. Furthermore, UCUF-965 enhanced angiogenesis markers and reduced wound healing time by 36% at 10.0 μM in diabetic mice models compared to untreated control.

Calcium silicate-stimulated adipose-derived stem cells promote angiogenesis and improve skin wound healing

Skin wound healing is a complicated process involving proliferation, inflammation, coagulation, and hemostasis, and scar tissue formation of wound repairing. Adipose-derived stem cells (ADSCs) have presented potential therapeutic effects in the non-healing and chronic wound. Calcium silicate (CS) ceramics have been identified as a new type of bioceramics for tissue construction and regeneration. Here, we aimed to explore the impact of CS on the regulation of ADSCs-mediated wound healing. Significantly, CS was able to dose-dependently enhance the proliferation of ADSCs. CS inhibited terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells in the H₂O₂-treated ADSCs. Similarly, the Bcl-2 expression was elevated while Bax and cleaved caspase-3 expression were repressed by CS in the cells. CS could induce migration and reduce oxidative stress of ADSCs. Moreover, immunofluorescence analysis and Western blot analysis showed that CS could promote CXCR4 expression in ADSCs. Moreover, CS-stimulated ADSCs enhanced migration and angiogenic capacity of HUVEC. Importantly, CS-stimulated ADSCs improved wound healing in full-thickness skin defect mouse model. Thus, we conclude that CS improves ADSCs-attenuated wound healing in vivo and in vitro. Our finding presents novel insight in the scenario that CS regulates ADSCs and wound healing. CS may be applied as potential materials for the treatment of wound healing.

Gene liposome nanocomplex-loaded dermal substitute promotes diabetic chronic wound healing and angiogenesis in rat

The incidence of chronic diabetic wounds is increasing with the growing number of diabetic patients, and conventional wound dressings have proven to be ineffective in treating them. To address this challenge, researchers have developed artificial dermal substitutes using collagen and hyaluronic acid, which are crucial extracellular matrices. However, these subsitiues lack precision and targeted treatment. To overcome this limitation, a gene liposome nanocomplex-loaded dermal substitute (GDS) has been developed as a potential solution. This innovative biomaterial combines the benefits of liposome nanocomplexes with dermal substitutes to offer a more accurate and effective treatment option for chronic diabetic wounds. The GDS has the ability to deliver genes and therapeutic agents specifically to the wound site, promoting angiogenesis and accelerating the wound healing process. Overall, the GDS presents a promising new approach for the clinical treatment of chronic diabetic wounds, offering a targeted and effective solution for this growing problem.

Various effects of 11,12 EET rescue wound healing in a combined model of diabetes and ischemia

Chronic non healing wounds in diabetic patients still impose a major problem in modern medicine. Especially additional peripheral vascular disease complicates treatment success in these patients. Thus, we analyzed the effects of 11,12 epoxyeicosatrienoic acid (EET) in a combined model of hyperglycemia and ischemia in mice. Hyperglycemia was induced by Streptozotozin 2 weeks prior to wounding. 3 days before wound creation 2 of the 3 suppling vessels of the moue ear were cautherized for ischemia. Either 11,12 EET or solvent for control was applied. Wound closure as well as TNF-α, TGF-β, SDF-1α, VEGF, CD31, and Ki67 were measured. The wounds closed on day 14.4 ± 0.4 standard deviation (SD). 11,12 EET treatment enhanced healing to 9.8 ± 0.6 SD. TNF-α level was augmented on day 9 compared to control and receded on day 18. TGF-β seemed to be elevated all days observed after 11,12 EET treatment. SDF-1α was enhanced on day 6 and 9 by 11,12 EET, and VEGF on day 6 and 18 as well as CD13 on day 3, 6, and 18. 11,12 EET did not alter Ki67. 11,12 EET are able to rescue deteriorated wound healing in a combined model of hyperglycamia and ischemia by resolution of inflammation, augmentation of neovascularization and increasing expression of TGF-β as well as SDF-1α.

Tissue engineering of decellularized pancreas scaffolds for regenerative medicine in diabetes

Diabetes mellitus is a global disease requiring long-term treatment and monitoring. At present, pancreas or islet transplantation is the only reliable treatment for achieving stable euglycemia in Type I diabetes patients. However, the shortage of viable pancreata for transplantation limits the use of this therapy for the majority of patients. Organ decellularization and recellularization is emerging as a promising solution to overcome the shortage of viable organs for transplantation by providing a potential alternative source of donor organs. Several studies on decellularization and recellularization of rodent, porcine, and human pancreata have been performed, and show promise for generating usable decellularized pancreas scaffolds for subsequent recellularization and transplantation. In this state-of-the-art review, we provide an overview of the latest advances in pancreas decellularization, recellularization, and revascularization. We also discuss clinical considerations such as potential transplantation sites, donor source, and immune considerations. We conclude with an outlook on the remaining work that needs to be done in order to realize the goal of using this technology to create bioengineered pancreata for transplantation in diabetes patients. STATEMENT OF SIGNIFICANCE: Pancreas or islet transplantation is a means of providing insulin-independence in diabetes patients. However, due to the shortage of viable pancreata, whole-organ decellularization and recellularization is emerging as a promising solution to overcome organ shortage for transplantation. Several studies on decellularization and recellularization of rodent, porcine, and human pancreata have shown promise for generating usable decellularized pancreas scaffolds for subsequent recellularization and transplantation. In this state-of-the-art review, we highlight the latest advances in pancreas decellularization, recellularization, and revascularization. We also discuss clinical considerations such as potential transplantation sites, donor source, and immune considerations. We conclude with future work that needs to be done in order to realize clinical translation of bioengineered pancreata for transplantation in diabetes patients.

Allogenic Adipose-Derived Stem Cells in Diabetic Foot Ulcer Treatment: Clinical Effectiveness, Safety, Survival in the Wound Site, and Proteomic Impact

Although encouraging results of adipose-derived stem cell (ADSC) use in wound healing are available, the mechanism of action has been studied mainly in vitro and in animals. This work aimed to examine the safety and efficacy of allogenic ADSCs in human diabetic foot ulcer treatment, in combination with the analyses of the wound. Equal groups of 23 participants each received fibrin gel with ADSCs or fibrin gel alone. The clinical effects were assessed at four time points: days 7, 14, 21 and 49. Material collected during debridement from a subset of each group was analyzed for the presence of ADSC donor DNA and proteomic changes. The reduction in wound size was greater at all subsequent visits, significantly on day 21 and 49, and the time to 50% reduction in the wound size was significantly shorter in patients who received ADSCs. Complete healing was achieved at the end of the study in seven patients treated with ADSCs vs. one treated without ADSCs. One week after ADSC application, 34 proteins significantly differentiated the material from both groups, seven of which, i.e., GAPDH, CAT, ACTN1, KRT1, KRT9, SCL4A1, and TPI, positively correlated with the healing rate. We detected ADSC donor DNA up to 21 days after administration. We confirmed ADSC-related improvement in wound healing that correlated with the molecular background, which provides insights into the role of ADSCs in wound healing-a step toward the development of cell-based therapies.

Chitosan/Sodium Alginate/Velvet Antler Blood Peptides Hydrogel Promotes Diabetic Wound Healing via Regulating Angiogenesis, Inflammatory Response and Skin Flora

Background

Diabetic ulcer remains a clinical challenge due to impaired angiogenesis and persistent inflammation, requiring new alternative therapies to promote tissue regeneration.

Purpose

In this study, chitosan/sodium alginate/velvet antler blood peptides (CS/SA/VBPs) hydrogel (CAVBPH) was fabricated and used in the treatment of skin wounds in type 2 diabetes mellitus (T2D) for the first time.

Methods

VBPs were prepared by hydrolysis and ultrafiltration, and their sequences were identified using LC-MS/MS. The CAVBPH was further fabricated and characterized. A mouse model of T2D was induced by a high-sugar and high-fat diet (HSFD) and streptozotocin (STZ) injection. CAVBPH was applied topically to T2D wounds, and its effects on skin repair and potential biological mechanisms were analyzed by appearance observation, histopathological staining, bioinformatics analysis, Western blot, and 16S rRNA sequencing.

Results

VBPs had numerous short-chain active peptides, excellent antioxidant activity, and a low hemolysis rate. CAVBPH exhibited desirable biochemical properties and participated in the diabetic wound healing process by promoting cell proliferation (PCNA and α-SMA) and angiogenesis (capillaries and CD31) and alleviating inflammation (CD68). Mechanistically, the therapeutic effect of CAVBPH on chronic wounds might rely on activating the PI3K/AKT/mTOR/HIF-1α/VEGFA pathway and reversing the expression of inflammatory cytokines TNF-α and IL-1β. The results of 16S rRNA sequencing indicated that T2D significantly altered the diversity and structure of skin flora at the wound site. CAVBPH treatment elevated the relative abundance of beneficial microbes (e.g., Corynebacterium_1 and Lactobacillus) and reversed the structural imbalance of skin microbiota.

Conclusion

These results indicate that CAVBPH is a promising wound dressing, and its repair effect on diabetic wounds by regulating angiogenesis, inflammatory response, and skin flora may depend on the rich small peptides in VBPs.

SDF-1α loaded bioengineered human amniotic membrane-derived scaffold transplantation in combination with hyperbaric oxygen improved diabetic wound healing

Based on its multifactorial nature, successful treatment of diabetic wounds requires combinatorial approach. In this regard, we hypothesized that engraftment of a bioengineered micro-porous three-dimensional human amniotic membrane-scaffold (HAMS) loaded by SDF-1α (SHAMS) in combination with hyperbaric oxygen (HBO), throughout mobilization and recruitment of endothelial progenitor cells (EPCs), could accelerate wound healing in rats with type 1 diabetes mellitus. To test this hypothesis, 30 days after inducting diabetes, an ischemic wound was created in rat skin and treatments were performed for 21 days. In addition to wounded non-diabetic (ND) group, diabetic animals were randomly divided into non-treated (NT-D), HBO-treated (HBO-D), HBO-treated plus HAMS transplantation (HBO+HAMS-D) or HBO-treated in combination with SHAMS transplantation (HBO+SHAMS-D) groups. Our results on post-wounding days 7, 14 and 21 showed that the wound closure, volume of new dermis and epidermis, numerical density of basal cells of epidermis, fibroblasts and blood vessels, number of proliferating cells, deposition of collagen and biomechanical properties of healed wound were considerably higher in both HBO+HAMS-D and HBO+SHAMS-D groups in comparison to those of the NT-D and HBO-D groups, and were the highest in HBO+SHAMS-D ones. The transcripts for Vegf, bFgf, and Tgf-β genes were significantly upregulated in all treatment regimens compared to NT-D group and were the highest for HBO+SHAMS-D group. This is while expression of Tnf-α and Il-1β as well as cell density of neutrophil and macrophage decreased more significantly in HBO+SHAMS-D group as compared with NT-D or HBO-D groups. Overall, it was found that using both HAMS transplantation and HBO treatment has more impact on diabetic wound healing. Moreover, SDF-1α loading on HAMS could transiently improve the wound healing process, as compared with the HBO+HAMS-D group on day 7 only.

11,12 Epoxyeicosatrienoic Acid Rescues Deteriorated Wound Healing in Diabetes

Epoxyeicosatrienoic acids (EET) facilitate regeneration in different tissues, and their benefit in dermal wound healing has been proven under normal conditions. In this study, we investigated the effect of 11,12 EET on dermal wound healing in diabetes. We induced diabetes by i.p. injection of streptozotocin 2 weeks prior to wound creation on the dorsal side of the mouse ear. 11,12 EET was applied every second day on the wound, whereas the control groups received only solvent. Epithelialization was monitored every second day intravitally up to wound closure. Wounds were stained for VEGF, CD31, TGF-β, TNF-α, SDF-1α, NF-κB, and Ki-67, and fibroblasts were counted after hematoxylin-eosin stain on days 3, 6, 9, and 16 after wounding. After induction of diabetes, wounds closed on day 13.00 ± 2.20 standard deviation (SD). Local 11,12 ETT application improved wound closure significantly to day 8.40 ± 1.39 SD. EET treatment enhanced VEGF and CD31 expression in wounds on day 3. It also seemed to raise TNF-α level on all days investigated as well as TGF-β level on days 3 and 6. A decrease in NF-κB could be observed on days 9 and 16 after EET application. The latter findings were not significant. SDF-1α expression was not influenced by EET application, and Ki-67 was significantly less in the EET group on day 9 after EET application. The number of fibroblasts was significantly increased on day 9 after the 11,12 EET application. 11,12 EET improve deteriorated wound healing in diabetes by enhancing neoangiogenesis, especially in the early phase of wound healing. Furthermore, they contribute to the dissolution of the initial inflammatory reaction, allowing the crucial transition from the inflammatory to proliferative phase in wound healing.

Adipose-Derived Stromal Cell-Sheets Sandwiched, Book-Shaped Acellular Dermal Matrix Capable of Sustained Release of Basic Fibroblast Growth Factor Promote Diabetic Wound Healing

The management of diabetic wounds is a therapeutic challenge in clinical settings. Current tissue engineering strategies for diabetic wound healing are insufficient, owing to the lack of an appropriate scaffold that can load a large number of stem cells and induce the interaction of stem cells to form granulation tissue. Herein we fabricated a book-shaped decellularized dermal matrix (BDDM), which shows a high resemblance to native dermal tissue in terms of its histology, microstructure, and ingredients, is non-cytotoxic and low-immunogenic, and allows adipose-derived stromal cell (ASC) attachment and proliferation. Then, a collagen-binding domain (CBD) capable of binding collagen was fused into basic fibroblast growth factor (bFGF) to synthetize a recombinant growth factor (termed as CBD-bFGF). After that, CBD-bFGF was tethered onto the collagen fibers of BDDM to improve its endothelial inducibility. Finally, a functional scaffold (CBD-bFGF/BDDM) was fabricated. In vitro and in vivo experiments demonstrated that CBD-bFGF/BDDM can release tethered bFGF with a sustained release profile, steadily inducing the interaction of stem cells down to endothelial differentiation. ASCs were cultured to form a cell sheet and then sandwiched by CBD-bFGF/BDDM, thus enlarging the number of stem cells loaded into the scaffold. Using a rat model, the ASC sheets sandwiched with CBD-bFGF/BDDM (ASCs/CBD-bFGF/BDDM) were capable of enhancing the formation of granulation tissue, promoting angiogenesis, and facilitating collagen deposition and remodeling. Therefore, the findings of this study demonstrate that ASCs/CBD-bFGF/BDDM could be applicable for diabetic wound healing.

Experimental Study on the Effect of Allogeneic Endothelial Progenitor Cells on Wound Healing in Diabetic Mice

Endothelial progenitor cells (EPCs) are involved in the neovascularization in traumatic and ischemic sites, but EPCs are "detained" in bone marrow under diabetic conditions, which results in reduction of the number of EPCs and their biological activity in peripheral blood. Based on our previous study to mobilize autologous bone marrow EPCs by administering AMD3100+G-CSF to realize the optimal effect, our present study is aimed at exploring the effects of transplanting EPCs locally in a wound model of diabetic mice. First, we prepared and identified EPCs, and the biological functions and molecular characteristics were compared between EPCs from DB/+ and DB/DB mice. Then, we performed full-thickness skin resection in DB/DB mice and tested the effect of local transplantation of EPCs on skin wound healing. The wound healing process was recorded using digital photographs. The animals were sacrificed on postoperative days 7, 14, and 17 for histological and molecular analysis. Our results showed that DB/+ EPCs were biologically more active than those of DB/DB EPCs. When compared with the control group, local transplantation of EPCs accelerated wound healing in DB/DB mice by promoting wound granulation tissue formation, angiogenesis, and collagen fiber deposition, but there was no significant difference in wound healing between DB/+ EPCs and DB/DB EPCs transplanted into the wound. Furthermore, local transplantation of EPCs promoted the expression of SDF-1, CXCR4, and VEGF. We speculated that EPC transplantation may promote wound healing through the SDF-1/CXCR4 axis. This point is worth exploring further. Present data are of considerable significance because they raise the possibility of promoting wound healing by isolating autologous EPCs from the patient, which provides a new approach for the clinical treatment of diabetic wounds in the future.

Skin-Associated B Cells in the Pathogenesis of Cutaneous Autoimmune Diseases-Implications for Therapeutic Approaches

B lymphocytes are crucial mediators of systemic immune responses and are known to be substantial in the pathogenesis of autoimmune diseases with cutaneous manifestations. Amongst them are lupus erythematosus, dermatomyositis, systemic sclerosis and psoriasis, and particularly those driven by autoantibodies such as pemphigus and pemphigoid. However, the concept of autoreactive skin-associated B cells, which may reside in the skin and locally contribute to chronic inflammation, is gradually evolving. These cells are believed to differ from B cells of primary and secondary lymphoid organs and may provide additional features besides autoantibody production, including cytokine expression and crosstalk to autoreactive T cells in an antigen-presenting manner. In chronically inflamed skin, B cells may appear in tertiary lymphoid structures. Those abnormal lymph node-like structures comprise a network of immune and stromal cells possibly enriched by vascular structures and thus constitute an ideal niche for local autoimmune responses. In this review, we describe current considerations of different B cell subsets and their assumed role in skin autoimmunity. Moreover, we discuss traditional and B cell-associated approaches for the treatment of autoimmune skin diseases, including drugs targeting B cells (e.g., CD19- and CD20-antibodies), plasma cells (e.g., proteasome inhibitors, CXCR4 antagonists), activated pathways (such as BTK- and PI3K-inhibitors) and associated activator molecules (BLyS, APRIL).

Regenerative medicine for anal incontinence: a review of regenerative therapies beyond cells

INTRODUCTION AND HYPOTHESIS

Current treatment modalities for anal sphincter injuries are ineffective for many patients, prompting research into restorative and regenerative therapies. Although cellular therapy with stem cells and progenitor cells show promise in animal models with short-term improvement, there are additional regenerative approaches that can augment or replace cellular therapies for anal sphincter injuries. The purpose of this article is to review the current knowledge of cellular therapies for anal sphincter injuries and discusses the use of other regenerative therapies including cytokine therapy with CXCL12.

METHODS

A literature search was performed to search for articles on cellular therapy and cytokine therapy for anal sphincter injuries and anal incontinence.

RESULTS

The article search identified 337 articles from which 33 articles were included. An additional 12 referenced articles were included as well as 23 articles providing background information. Cellular therapy has shown positive results for treating anal sphincter injuries and anal incontinence in vitro and in one clinical trial. However, cellular therapy has disadvantages such as the source and processing of stem cells and progenitor cells. CXCL12 does not have such issues while showing promising in vitro results for treating anal sphincter injuries. Additionally, electrical stimulation and extracorporeal shock wave therapy are potential regenerative medicine adjuncts for anal sphincter injuries. A vision for future research and clinical applications of regenerative medicine for anal sphincter deficiencies is provided.

CONCLUSION

There are viable regenerative medicine therapies for anal sphincter injuries beyond cellular therapy. CXCL12 shows promise as a focus of therapeutic research in this field.

Effect of Mineral Pitch on the Proliferation of Human Adipose Derived Stem Cells on Acellular Scaffold

Purpose: Acellular scaffold extracted from extracellular matrix (ECM) have been used for constructive and regenerative medicine. Adipose derived stem cells (ADSCs) can enhance the vascularization capacity of scaffolds. High mobility group box 1 (HMGB1) and stromal derived factor1 (SDF1) are considered as two important factors in vascularization and immunologic system. In this study, the effect of mineral pitch on the proliferation of human ADSCs was evaluated. In addition to HMGB1 and SDF1, factors expression in acellular scaffold was also assessed.

Methods: To determine acellular scaffold morphology and the degree of decellularization, hematoxylin & eosin (H&E), 6-diamidino-2-phenylindole (DAPI), and Masson’s trichrome staining were applied. The scaffolds were treated with mineral pitch. Also, ADSCs were seeded on the scaffolds, and adhesion of the cells to the scaffolds were assessed using field emission scanning electron microscopy (FE-SEM). In addition, the efficiency of mineral pitch to induce the proliferation of ADSCs on the scaffolds was evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. To measure HMGB1 and SDF1 mRNA expression, real-time polymerase chain reactions (RT-PCR) was used.

Results: FE-SEM showed that decellularized matrix possesses similar matrix morphology with a randomly oriented fibrillar structure and interconnecting pores. No toxicity was observed in all treatments, and cell proliferation were supported in scaffolds. The important point is that, the proliferation capacity of ADSCs on Mineral pitch loaded scaffolds significantly increased after 48 h incubation time compared to the unloaded scaffold (P<0.001).

Conclusion: The results of this study suggest that mineral pitch has potentials to accelerate proliferation of ADSCs on the acellular scaffolds.

Role of the SDF-1/CXCR4 signaling pathway in cartilage and subchondral bone in temporomandibular joint osteoarthritis induced by overloaded functional orthopedics in rats

OBJECTIVES

To (i) use a mandibular advancement appliance in rats to investigate the role of the stromal cell-derived factor/CXC receptor 4 (SDF-1/CXCR4) signaling pathway in temporomandibular joint osteoarthritis (TMJ OA) induced by overloaded functional orthopedics (OFO) and (ii) provide a cellular and molecular basis for efficacious treatment of skeletal class-II malocclusion and avoidance of TMJ OA.

METHOD

Male Sprague-Dawley rats (6 weeks) were divided randomly into control + normal saline (NS), EXP + ADM3100 (SDF-1 antagonist), EXP + NS, and control + ADM3100 groups. Changes in articular cartilage and subchondral bone after TMJ OA in these four groups were observed by hematoxylin and eosin (H&E), immunofluorescence double staining (IDS), Safranin-O staining, immunohistochemical (IHC) staining, real-time polymerase chain reaction, and micro-computed tomography at 2, 4, and 8 weeks.

RESULTS

OFO led to increased expression of SDF-1, CXCR4, and matrix metalloproteinase (MMP) 13 and decreased expression of collagen II. The thickness of the hypertrophic cartilage layer was reduced at 4 weeks in the EXP + NS group, and damage to subchondral bone was observed at 2 weeks. Using ADM3100 to inhibit SDF-1 signaling could attenuate expression of MMP13, cartilage damage, and osteoblast differentiation. IDS showed that the areas of expression of SDF-1 and OSX in subchondral bone overlapped.

CONCLUSIONS

Overloaded functional orthopedics (OFO) induced TMJ OA. The destruction of subchondral bone in TMJ OA caused by OFO occurred before damage to cartilage. SDF-1/CXCR4 may induce the osteogenic differentiation and cause cartilage degradation in TMJ OA caused by OFO.

A Mini Review: Stem Cell Therapy for Osteonecrosis of the Femoral Head and Pharmacological Aspects

Osteonecrosis of the femoral head (ONFH) is a common disease that occurs frequently. Due to various etiologies, the blood supply directed to the femoral head is interrupted in patients with ONFH. This disease can result in degeneration and necrosis of the subchondral bone of the femoral head, which ultimately cause a collapse of the femoral head. Of note, ONFH can extremely affect the quality of living of patients with a high disability rate. Also, this disease often includes middle-aged and younger people. However, effective treatments of ONFH are still challenging in clinics. In recent years, stem cells have been profoundly studied and a relevant new technology has been developed rapidly and applied for regenerative medicine. A number of reports have demonstrated successful results of the treatment of ONFH by using stem cell transplantation. By the combination of minimally invasive hip decompression and injection of mesenchymal stem cells into the necrotic lesion, the retrospective analysis of patients treated revealed that significant pain relief was observed in 86% patients and they had no major complications after treatment. Thus, stem cell transplantation is anticipated to be applied as an innovative approach in the treatment of ONFH. This review will summarize results obtained from recent human and animal studies, which include the pathophysiological process of ONFH, current techniques and effects of using stem cells on the treatment of ONFH together with pharmacological aspects. Overall, the current evidence reveals the treatment of ONFH using stem cell technology as promising. Nonetheless, additional in-depth studies are necessary to better explore the application of this technology and seek more ideal approaches to minimize difficulties related to stem cells.

A dual functional collagen scaffold coordinates angiogenesis and inflammation for diabetic wound healing

Chronic diabetic wounds, which are associated with persistent inflammation and impaired angiogenesis, occur frequently in diabetic patients.

Evaluation of bone-regeneration effects and ectopic osteogenesis of collagen membrane chemically conjugated with stromal cell-derived factor-1 in vivo

Because the collagen membrane lacks osteoinductivity, it must be modified with bioactive components to trigger rapid bone regeneration. In this study, we aimed to evaluate the bone regeneration effects of a collagen membrane chemically conjugated with stromal cell-derived factor-1 alpha (SDF-1α) in rat models. To this end, different collagen membranes from four groups including a control group with a Bio-Oss bone substitute + collagen membrane; physical adsorption group with Bio-Oss + SDF-1α physically adsorbed on the collagen membrane; chemical cross-linking group with Bio-Oss + SDF-1α chemically cross-linked to the collagen membrane; and cell-seeding group with Bio-Oss + bone marrow mesenchymal stem cells (BMSCs) seeded onto the collagen membrane were placed in critical-sized defect models using a guided bone regeneration technique. At 4 and 8 weeks, the specimens were analyzed by scanning electron microscopy, energy-dispersive x-ray spectroscopy, micro-computed tomography, and histomorphology analyzes. Furthermore, ectopic osteogenesis was examined by histological analysis with Von Kossa staining, with the samples counterstained by hematoxylin and eosin and immunohistochemical staining. The results showed that in the chemical cross-linking group and cell-seeding group, the bone volume fraction, bone surface area fraction, and trabecular number were significantly increased and showed more new bone formation compared to the control and physical adsorption groups. Von Kossa-stained samples counterstained with hematoxylin and eosin and subjected to immunohistochemical staining of 4-week implanted membranes revealed that the chemical cross-linking group had the largest number of microvessels. The collagen membrane chemically conjugated with SDF-1α to significantly promote new bone and microvessel formation compared to SDF-1α physical adsorption and showed similar effects on new bone formation as a BMSC seeding method. This study provided a cell-free approach for shortening the bone healing time and improving the success rate of guided bone regeneration.

Biomimetic Synthesis of Nanocrystalline Hydroxyapatite Composites: Therapeutic Potential and Effects on Bone Regeneration

The development of a novel alloplastic graft with both osteoinductive and osteoconductive properties is still necessary. In this study, we tried to synthesize a biomimetic hydroxyapatite microspheres (gelatin/nano-hydroxyapatite microsphere embedded with stromal cell-derived factor-1: GHM-S) from nanocrystalline hydroxyapatites and to investigate their therapeutic potential and effects on bone regeneration. In this study, hydroxyapatite was synthesized by co-precipitation of calcium hydroxide and orthophosphoric acid to gelatin solution. The microbial transglutaminase was used as the agent to crosslink the microspheres. The morphology, characterization, and thermal gravimetric analysis of microspheres were performed. SDF-1 release profile and in vitro biocompatibility and relative osteogenic gene expression were analyzed, followed by in vivo micro-computed tomography study and histological analysis. The synthesized hydroxyapatite was found to be similar to hydroxyapatite of natural bone tissue. The stromal cell-derived factor-1 was embedded into gelatin/hydroxyapatite microsphere to form the biomimetic hydroxyapatite microsphere. The stromal cell-derived factor-1 protein could be released in a controlled manner from the biomimetic hydroxyapatite microsphere and form a concentration gradient in the culture environment to attract the migration of stem cells. Gene expression and protein expression indicated that stem cells could differentiate or develop into pre-osteoblasts. The effect of bone formation by the biomimetic hydroxyapatite microsphere was assessed by an in vivo rats’ alveolar bone defects model and confirmed by micro-CT imaging and histological examination. Our findings demonstrated that the biomimetic hydroxyapatite microsphere can enhance the alveolar bone regeneration. This design has potential be applied to other bone defects.

Endothelial progenitor cell therapy for chronic wound tissue regeneration

Despite advancements in wound care, healing of chronic diabetic wounds remains a great challenge for the clinical fraternity because of the intricacies of the healing process. Due to the limitations of existing treatment strategies for chronic wounds, stem/progenitor cell transplantation therapies have been explored as an alternative for tissue regeneration at the wound site. The non-healing phenotype of chronic wounds is directly associated with lack of vascularization. Therefore, endothelial progenitor cell (EPC) transplantation is proving to be a promising approach for the treatment of hypo-vascular chronic wounds. With the existing knowledge in EPC biology, significant efforts have been made to enrich EPCs at the chronic wound site, generating EPCs from somatic cells, induced pluripotent stem cells (iPSCs) using transcription factors, or from adult stem cells using chemicals/drugs for use in transplantation, as well as modulating the endogenous dysfunctional/compromised EPCs under diabetic conditions. This review mainly focuses on the pre-clinical and clinical approaches undertaken to date with EPC-based translational therapy for chronic diabetic as well as non-diabetic wounds to evaluate their vascularity-mediated regeneration potential.

Reduced Graphene Oxide Incorporated Acellular Dermal Composite Scaffold Enables Efficient Local Delivery of Mesenchymal Stem Cells for Accelerating Diabetic Wound Healing

Chronic skin wounds caused by diabetes mellitus (DM) have been acknowledged as one of the most intractable complications. Local transplantation of mesenchymal stem cells (MSCs) is a promising method, but strategies for stabilizing and efficiently delivering active MSCs according to the wound circumstance with high proteolysis remain the main barrier. Hereon, the study demonstrates the feasibility of incorporating reduced graphene oxide (RGO) nanoparticles with an acellular dermal matrix (ADM) to improve physicochemical characteristics of natural scaffold material and fabricate a highly efficient local transplantation system for MSCs in diabetic wound healing. Under the influence of RGO nanoparticles, the ADM-RGO composite scaffolds achieved high stability and strong mechanical behaviors. In vitro, conductive ADM-RGO scaffolds demonstrated an admirable milieu for stem cells adhesion and proliferation. After having been cocultured with MSCs, the ADM-RGO-MSC composite scaffolds were transplanted into the full-thickness wound of a diabetic model that was induced by streptozotocin (STZ) to evaluate its effects. As a result, the ADM-RGO composite scaffold delivered with MSCs supported robust vascularization and collagen deposition as well as rapid re-epithelialization during diabetic wound healing. Overall, the versatile nature of the ADM-RGO composite scaffold makes it an efficient transplanting mediator for pluripotent stem cells in tissue engineering applications. The composite scaffold delivered with MSCs presents a promising approach for nonhealing diabetic wounds.