Antiwrinkle effect of adipose-derived stem cell: Activation of dermal fibroblast by secretory factors

Adipose-Derived Mesenchymal Stem Cells and Their Derived Epidermal Progenitor Cells Conditioned Media Ameliorate Skin Aging in Rats

BACKGROUND

Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging.

METHODS

In this study, we isolated and characterized adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of male Sprague Dawley rats. We assessed the in vitro differentiation of Ad-MSCs into epidermal progenitor cells (EPCs) using ascorbic acid and hydrocoritsone. Additionally, we induced skin aging in female Sprague Dawley rats via daily intradermal injection of D-galactose over a period of 8 weeks. Then we evaluated the therapeutic potential of intradermal transplantation of Ad-MSCs and conditioned media (CM) derived from differentiated EPCs in the D-galactose-induced aging rats. Morphological assessments, antioxidant assays, and histopathological examinations were performed to investigate the effects of the treatments.

RESULTS

Our findings revealed the significant capability of Ad-MSCs to differentiate into EPCs. Notably, compared to the group that received CM treatment, the Ad-MSCs-treated group exhibited a marked improvement in morphological appearance, antioxidant levels and histological features.

CONCLUSIONS

These results underscore the effectiveness of Ad-MSCs in restoring skin aging as a potential therapy for skin aging.

Exploring the biphasic dose-response effects of photobiomodulation on the viability, migration, and extracellular vesicle secretion of human adipose mesenchymal stem cells

Photobiomodulation (PBM) is a well-established medical technology that employs diverse light sources like lasers or light-emitting diodes to generate diverse photochemical and photophysical reactions in cells, thereby producing beneficial clinical outcomes. In this study, we introduced an 830 nm near-infrared (NIR) laser irradiation system combined with a microscope objective to precisely and controllably investigate the impact of PBM on the migration and viability of human adipose mesenchymal stem cells (hADSCs). We observed a biphasic dose-response in hADSCs' viability and migration after PBM exposure (0-10 J/cm2), with the 5 J/cm2 group showing significantly higher cell viability and migration ability than other groups. Additionally, at the optimal dose of 5 J/cm2, we used nanoparticle tracking analysis (NTA) and found a 6.25-fold increase in the concentration of extracellular vesicles (EVs) derived from hADSCs (PBM/ADSC-EVs) compared to untreated cells (ADSC-EVs). Both PBM/ADSC-EVs and ADSC-EVs remained the same size, with an average diameter of 56 nm measured by the ExoView R200 system, which falls within the typical size range for exosomes. These findings demonstrate that PBM not only improves the viability and migration of hADSCs but also significantly increases the EV yield.

Upcycled canola meal extract mitigates UVB-induced skin wrinkling by regulating photoaging-related biomarkers in hairless mice

Canola meal, a by-product of processing canola into oil, reportedly contains high amounts of phenolic compounds and proteins. However, as canola meal is primarily used as feed for livestock, advances in multiple research fields are required to broaden its potential applications. Photoaging is caused by continuous exposure to ultraviolet (UV) radiation from sunlight. UV radiation generates reactive oxygen species and destroys collagen in the skin, thickening the epidermis, reducing elasticity, and causing wrinkles. We hypothesized that canola meal extract (CME) can mitigate the damage to skin associated with wrinkles induced by exposure to UVB radiation. To evaluate the anti-wrinkle effect, we administered CME orally to 40 female Hos:HR-1 hairless mice divided into 5 groups: (1) control mice, (2) a UVB group, and (3-5) CME-treated groups (CME-250, 500, and 1000 mg/kg body weight/day, respectively). All groups except the controls were irradiated with UVB 3 times a week to create wrinkles due to photoaging. CME administration inhibited the increase of the number, mean length, and mean depth of wrinkles induced by UVB radiation as assessed using a skin replica. Histopathological image analysis revealed that CME administration resulted in a decrease in epidermal thickness and an increase in collagen content, while increasing catalase activity and hydroxyproline content in skin tissues. CME administration inhibited the phosphorylation of mitogen-activated protein kinase and decreased the production of collagenase and gelatinase. These results suggest that CME, an upcycled material, has the potential to develop into a healthful and functional food ingredient with anti-wrinkling effects.

Fibroblast function recovery through rejuvenation effect of nanovesicles extracted from human adipose-derived stem cells irradiated with red light

Fibroblasts (hDFs) are widely employed for skin regeneration and the treatment of various skin disorders, yet research were rarely investigated about restoration of diminished therapeutic efficacy due to cell senescence. The application of stem cell and stem cell-derived materials, exosomes, were drawn attention for the restoration functionality of fibroblasts, but still have limitation for unintended side effect or low yield. To advance, stem cell-derived nanovesicle (NV) have developed for effective therapeutic reagents with high yield and low risk. In this study, we have developed a method using red light irradiated human adipose-derived stem cells (hADSCs) derived NV (R-NVs) for enhancing the therapeutic efficacy and rejuvenating hDFs. Through red light irradiation, we were able to significantly increase the content of stemness factors and angiogenic biomolecules in R-NVs. Treatment with these R-NVs was found to enhance the migration ability and leading to rejuvenation of old hDFs to levels similar to those of young hDFs. In subsequent in vivo experiments, the treatment of old hDFs with R-NVs demonstrated a superior skin wound healing effect, surpassing that of young hDFs. In summary, this study successfully induced rejuvenation and leading to increased therapeutic efficacy to R-NVs treated old hDFs previously considered as biowaste.

The Role and Prospects of Mesenchymal Stem Cells in Skin Repair and Regeneration

Mesenchymal stem cells (MSCs) have been recognized as a cell therapy with the potential to promote skin healing. MSCs, with their multipotent differentiation ability, can generate various cells related to wound healing, such as dermal fibroblasts (DFs), endothelial cells, and keratinocytes. In addition, MSCs promote neovascularization, cellular regeneration, and tissue healing through mechanisms including paracrine and autocrine signaling. Due to these characteristics, MSCs have been extensively studied in the context of burn healing and chronic wound repair. Furthermore, during the investigation of MSCs, their unique roles in skin aging and scarless healing have also been discovered. In this review, we summarize the mechanisms by which MSCs promote wound healing and discuss the recent findings from preclinical and clinical studies. We also explore strategies to enhance the therapeutic effects of MSCs. Moreover, we discuss the emerging trend of combining MSCs with tissue engineering techniques, leveraging the advantages of MSCs and tissue engineering materials, such as biodegradable scaffolds and hydrogels, to enhance the skin repair capacity of MSCs. Additionally, we highlight the potential of using paracrine and autocrine characteristics of MSCs to explore cell-free therapies as a future direction in stem cell-based treatments, further demonstrating the clinical and regenerative aesthetic applications of MSCs in skin repair and regeneration.

The Efficacy of Stem Cells in Wound Healing: A Systematic Review

Wound healing is an intricate process involving coordinated interactions among inflammatory cells, skin fibroblasts, keratinocytes, and endothelial cells. Successful tissue repair hinges on controlled inflammation, angiogenesis, and remodeling facilitated by the exchange of cytokines and growth factors. Comorbid conditions can disrupt this process, leading to significant morbidity and mortality. Stem cell therapy has emerged as a promising strategy for enhancing wound healing, utilizing cells from diverse sources such as endothelial progenitor cells, bone marrow, adipose tissue, dermal, and inducible pluripotent stem cells. In this systematic review, we comprehensively investigated stem cell therapies in chronic wounds, summarizing the clinical, translational, and primary literature. A systematic search across PubMed, Embase, Web of Science, Google Scholar, and Cochrane Library yielded 22,454 articles, reduced to 44 studies after rigorous screening. Notably, adipose tissue-derived mesenchymal stem cells (AD-MSCs) emerged as an optimal choice due to their abundant supply, easy isolation, ex vivo proliferative capacities, and pro-angiogenic factor secretion. AD-MSCs have shown efficacy in various conditions, including peripheral arterial disease, diabetic wounds, hypertensive ulcers, bullous diabeticorum, venous ulcers, and post-Mohs micrographic surgery wounds. Delivery methods varied, encompassing topical application, scaffold incorporation, combination with plasma-rich proteins, and atelocollagen administration. Integration with local wound care practices resulted in reduced pain, shorter healing times, and improved cosmesis. Stem cell transplantation represents a potential therapeutic avenue, as transplanted stem cells not only differentiate into diverse skin cell types but also release essential cytokines and growth factors, fostering increased angiogenesis. This approach holds promise for intractable wounds, particularly chronic lower-leg wounds, and as a post-Mohs micrographic surgery intervention for healing defects through secondary intention. The potential reduction in healthcare costs and enhancement of patient quality of life further underscore the attractiveness of stem cell applications in wound care. This systematic review explores the clinical utilization of stem cells and stem cell products, providing valuable insights into their role as ancillary methods in treating chronic wounds.

Histological Comparison of Nanofat and Lipoconcentrate: Enhanced Effects of Lipoconcentrate on Adipogenesis and Angiogenesis

BACKGROUND

Nanofat and lipoconcentrate contain adipose-derived stem cells and growth factors, and have wide clinical applications in the regenerative field. This study aimed to investigate the microenvironmental changes associated with nanofat and lipoconcentrate.

METHODS

Conventional fat, nanofat, or lipoconcentrate (0.2 mL each, n = 5 per group) were injected subcutaneously into the dorsal flanks of athymic nude mice. The graft weights were measured at postoperative week 4; the grafts and their overlying skin were used for histological analyses.

RESULTS

Weights of the lipoconcentrate grafts were significantly greater than those of the conventional fat (p < 0.05) and nanofat (p < 0.01) grafts. There was no significant difference in inflammation, oil cysts, and fibrosis between the conventional fat and nanofat groups. Histological examination of the lipoconcentrate grafts showed less macrophage infiltration and the formation of fibrosis and oil cysts. Additionally, adipogenesis and angiogenesis were induced more in the lipoconcentrate grafts than in the nanofat grafts (p < 0.01). Lipoconcentrate and nanofat improved dermal thickness (p < 0.001 and p < 0.01, respectively, versus the baseline).

CONCLUSION

Lipoconcentrate grafts had greater volume and shape retention than conventional fat and nanofat grafts. They had better histological structure and acted as scaffolds for adipogenesis and angiogenesis. Both products showed regenerative effects on dermal thickness; however, only lipoconcentrate grafts had the required volume and regenerative effects, allowing it to serve as a novel adipose-free grafting method for facial rejuvenation and contouring.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Positive effects of hypoxic preconditioning of the extracellular matrix and stromal vascular fraction from adipose tissue

Background

Numerous approaches have been developed to decelerate the aging process of facial skin. Synthetic fillers and cell-enriched fat grafts are the main procedures employed to fill wrinkles.

Objective

The aim of this study was to evaluate the in vitro and in vivo safety and efficiency of a new process developed by SYMBIOKEN: the AmeaCell, which facilitates the extraction of the stromal vascular fraction (SVF) and the associated hypoxia pre-conditioned matrix to promote fat graft survival.

Methods

The AmeaCell device allows the extraction from adipose tissue of SVF and pre-conditioned MatriCS and promotes a hypoxic environment. Experiments were carried out on human cells and then in mice.

Results

Characterization of cells and MatriCS showed that after their extraction using the new process developed by SYMBIOKEN, the extracted cells expressed stem-cell markers. The presence of characteristic proteins and lipid fractions found in the adipose matrix were confirmed in MatriCS. Cobalt chloride treatment of the matrix using the AmeaCell device induced modifications in the matrix composition with a decrease in laminin and without collagen modification, both of which promote adhesion and differentiation of SVF or adipose-derived stromal cells. The combination of MatriCS and SVF (1 × 106 and 5 × 106, respectively) is safe and efficient to fill winkles induced by UVB irradiation. The cross-talk between MatriCS and SVF can act a durable filler compared to the filling performed using cells or matrix or fat alone, which need to be replaced frequently.

Conclusion

These results indicate that the combination of MatriCS and SVF is safe and effective as a biological filler for achieving skin rejuvenation and wrinkle filling.

Progress in the Development of Stem Cell-Derived Cell-Free Therapies for Skin Aging

Introduction

The skin is a vital organ as the body's largest barrier, but its function declines with aging. Therefore, research into effective regeneration treatments must continue to advance. Stem cell transplantation, a cell-based therapy, has become a popular skin-aging treatment, although it comes with drawbacks like host immune reactions. Stem cell-derived cell-free therapies have emerged as an alternative, backed by promising preclinical findings. Stem cell secretomes and extracellular vesicles (EVs) are the key components in cell-free therapy from stem cells. However, comprehensive reviews on the mechanisms of such treatments for skin aging are still limited.

Purpose

This review discusses stem cell-derived cell-free therapy's potential mechanisms of action related to skin aging prevention by identifying specific molecular targets suitable for the interventions.

Methods

A search identified 27 relevant in vitro studies on stem cell-derived cell-free therapy interventions in skin aging model cells without restricting publication years using PubMed, Scopus, and Google Scholar.

Results

Stem cell-derived cell-free therapy can prevent skin aging through various mechanisms, such as (1) involvement of multiple regenerative pathways [NFkb, AP-1, MAPK, P-AKT, NRF2, SIRT-1]; (2) oxidative stress regulation [by reducing oxidants (HO-1, NQO1) and enhancing antioxidants (SOD1, CAT, GP, FRAP)]; (3) preventing ECM degradation [by increasing elastin, collagen, HA, TIMP, and reducing MMP]; (4) regulating cell activity [by reducing cell senescence (SA-β-gal), apoptosis, and cell cycle arrest (P53, P12, P16); and enhancing autophagy, cell migration, and cell proliferation (Ki67)] (5) Regulating the inflammatory pathway [by reducing IL-6, IL-1, TNF-⍺, and increasing TGF-β]. Several clinical trials have also revealed improvements in wrinkles, elasticity, hydration, pores, and pigmentation.

Conclusion

Stem cell-derived cell-free therapy is a potential novel treatment for skin aging by cell rejuvenation through various molecular mechanisms.

Outcomes of Autologous Fat Graft Injection(s) in Treating Sequelae of Digital Trauma: A Case Series

Background: Sequelae of digital trauma, such as painful scars adherent to tendons and bones, pain of neural origin, cold intolerance, skin and pulp atrophy, occur frequently. Autologous fat graft injections is an interesting option to treat these sequelae. The aim of this study is to describe the outcomes of autologous fat graft injections to treat sequelae of digital trauma. Methods: This retrospective study included all adult patients with digital trauma who underwent an autologous fat grafting procedure at our hospital between 2015 and 2019. The procedure was done at least 6 months after the initial trauma. Outcomes were assessed at least 9 months after the injection and included 2-point epicritic discrimination by Weber test (2-PD) and pulp circumference of the affected finger compared with the contralateral finger, a satisfaction questionnaire concerning the improvement of symptoms, aesthetic aspects and pain related to the operation, evaluation of pain by visual analogue scale, quality of life by SF-36 score and quick disabilities of the arm, shoulder and hand questionnaire (QuickDASH) score. We also assessed whether the patients had reintegrated a previously excluded finger. Results: The study included 14 patients. All patients received one session except for one patient who received two sessions. The average 2-PD of the injured finger was 7 mm compared to 3.57 mm for the contralateral finger. There was no difference in pulp circumference between the treated and contralateral fingers. The mean satisfaction score for symptom improvement and aesthetic improvement was 3.36/5, and the mean score for procedure-related pain was 2.36/5. The mean VAS of the patients was 2.91/10, the mean SF-36 was 60.42/100 and the mean QuickDASH was 40.09/100. Five of the nine patients who had a previously excluded finger were able to reintegrate it. Conclusions: Autologous fat transfer seems to offer some benefit in patients with adherent scars and pulp atrophy. It has little effect on neuropathic pain. Level of Evidence: Level IV (Therapeutic).

A Single Intradermal Injection of Autologous Adipose-Tissue-Derived Stem Cells Rejuvenates Aged Skin and Sharpens Double Eyelids

Facial skin aging is the most visible manifestation of aging in the body. In this study, we aimed to rejuvenate aging skin via a one-time intradermal injection of autologous adipose-derived stem cells (ADSCs). Eight patients were enrolled for study. Photographs of patients taken immediately before and 1, 3, 6, and 12 months after ADSC injections were comparatively evaluated for visible skin manifestations. ADSCs were cultured from the abdominal-skin-derived subcutaneous fat tissue, and 1 × 108 cultured ADSCs were injected intradermally into the facial skin. Cultured myoblasts were incubated with the supernatant derived from ADSCs, and the effect was evaluated via glucose consumption and lactic acid production in the medium. Eight cases showed the shallowing and disappearance of wrinkles, including those of the glabella, lower eyelids, crow`s feet, and forehead and nasolabial grooves, a month to several months after treatment. Double eyelids became prominent, and facial pores significantly reduced in size. These effects lasted for over one year. Myoblasts cultured in the presence of an ADSC-derived exosome were activated compared to that of ADSCs cultured without supernatant. The result supports the role of muscle in ADSC skin rejuvenation. The present study first reports that a single intradermal administration of cultured ADSCs rejuvenates aged facial skin over the course of one year. Further, patients exhibited definite double eyelids and pore shrinkage, strongly indicating the active involvement of muscle, which was supported by an in vitro study. Our study also suggested the important role of biological factors delivered from injected stem cells, although the detailed mechanism of rejuvenation effects of ADSC skin injection remains to be clarified.

Investigation of UV-treated mesenchymal stem cells in an in vitro wound model

This study examines the effects of ultraviolet-induced adipose tissue-derived mesenchymal stem cells and their supernatants on wound healing regarding cell viability, percentage of wound healing, released cytokine, and growth factors. It has been reported in previous studies that mesenchymal stem cells are resistant to ultraviolet light and have a protective effect on skin cells against ultraviolet-induced damage. At the same time, there are many studies in the literature about the positive effects of cytokines and growth factors secreted by mesenchymal stem cells. Based on this information, the effects of ultraviolet-induced adipose-derived stem cells and supernatants containing their secreted cytokines and growth factors on an in vitro two-dimensional wound model created with two different cell lines were investigated in this study. It was determined from the results that the highest cell viability and the least apoptotic staining were 100 mJ in mesenchymal stem cells (**p < 0.01). Furthermore, analysis of cytokines and growth factors collected from supernatants also supported 100 mJ as the optimal ultraviolet dose. It was observed that cells treated with ultraviolet and their supernatants significantly increased cell viability and wound-healing rate over time compared to other groups. In conclusion, with this study, it has been shown that adipose-derived stem cells exposed to ultraviolet light can have an important use in wound healing, both with their potential and with the more cytokines and growth factors they secrete. However, further analysis and animal experiments should be performed before clinical use.

Unraveling White Adipose Tissue Heterogeneity and Obesity by Adipose Stem/Stromal Cell Biology and 3D Culture Models

The immune and endocrine dysfunctions of white adipose tissue are a hallmark of metabolic disorders such as obesity and type 2 diabetes. In humans, white adipose tissue comprises distinct depots broadly distributed under the skin (hypodermis) and as internal depots (visceral). Depot-specific ASCs could account for visceral and subcutaneous adipose tissue properties, by regulating adipogenesis and immunomodulation. More importantly, visceral and subcutaneous depots account for distinct contributions to obesity and its metabolic comorbidities. Recently, distinct ASCs subpopulations were also described in subcutaneous adipose tissue. Interestingly, the superficial layer closer to the dermis shows hyperplastic and angiogenic capacities, whereas the deep layer is considered as having inflammatory properties similar to visceral. The aim of this focus review is to bring the light of recent discoveries into white adipose tissue heterogeneity together with the biology of distinct ASCs subpopulations and to explore adipose tissue 3D models revealing their advantages, disadvantages, and contributions to elucidate the role of ASCs in obesity development. Recent advances in adipose tissue organoids opened an avenue of possibilities to recreate the main cellular and molecular events of obesity leading to a deep understanding of this inflammatory disease besides contributing to drug discovery. Furthermore, 3D organ-on-a-chip will add reproducibility to these adipose tissue models contributing to their translation to the pharmaceutical industry.

Adipose-Derived Stem Cells Attenuate Skin Fibrosis and Improve Fat Retention of a Localized Scleroderma Mouse Model

BACKGROUND

Although autologous fat grafting is a feasible surgical technique to improve facial deformity in patients with localized scleroderma, its success is limited by the low graft retention induced by the local inflammatory environment. This study investigated the potential effect of adipose-derived stem cells (ASCs) on skin fibrosis and fat retention in a localized scleroderma mouse model.

METHODS

BALB/C nude mice that were induced by bleomycin to establish a localized scleroderma model were divided randomly into five groups: blank control; fat grafting; and low, moderate, and high doses of ASC-assisted fat grafting. The backs of the mice were subcutaneously injected with phosphate-buffered saline or fat, or fat with low, moderate, and high doses of ASCs (1 × 10 5 /mL, 5 × 10 5 /mL, and 25 × 10 5 /mL, respectively). The skin fibrosis and fat retention were analyzed after 1 month or 3 months, respectively.

RESULTS

Compared to the disease model group, the fat-grafting group, and the low- and moderate-dose ASC-enriched groups, the high-dose ASCs significantly attenuated skin fibrosis, inhibited the production of type III collagen and transforming growth factor-β1, increased fat graft retention, enhanced the expression of angiogenesis-related cytokines and angiogenesis, and increased the expression of adipogenesis-related cytokines.

CONCLUSIONS

The results demonstrated that high-dose ASCs attenuated skin fibrosis and improved fat retention in a localized scleroderma model by reducing inflammation and by promoting angiogenesis and adipogenesis. The authors further demonstrated that ASCs enhanced adipogenesis through the AKT/ERK signaling pathway.

CLINICAL RELEVANCE STATEMENT

Fat grafting has been used to treat localized scleroderma patients but with low fat retention. In this study, ASC attenuated skin fibrosis and improved fat retention in the localized scleroderma model, providing evidence for cell therapy in future application of localized scleroderma treatment.

Secretome of human umbilical cord mesenchymal stem cell maintains skin homeostasis by regulating multiple skin physiological function

Skin is the largest organ in the body and the first defense to resist various diseases and external stimuli that easily cause infection and inflammation. Aseptic inflammation, barrier damage, and foreign aid pressure induce the destruction and damage to the skin microenvironment. Subsequently, it destroys the skin's physiological function, leading to the maintenance and circulation of steady-state imbalance and aggravating the process of skin disorders. Our study evaluated the therapeutic potential of the secretome of human umbilical cord mesenchymal stem cells (UC-CM) for dermatological diseases in adult human skin cells, ex vivo skin tissue, and a 3D skin model. Our data suggested several advantages of UC-CM due to (1) their low cytotoxicity and sensitization properties; (2) their anti-inflammatory capacity for treating inflammatory chronic cutaneous diseases; (3) their enhanced capacity of the skin barrier for treating abnormal barrier metabolism; and (4) their positive impact on restoring skin homeostasis due to effective regulation ability of skin physiological function including cell apoptosis, detoxification, and anti-aging. We thus envisage that the possibility of harnessing the therapeutic potential of UC-CM might benefit patients suffering from inflammatory skin disorders such as atopic dermatitis, acne, and psoriasis.

Adipose-derived stem cells attenuate acne-related inflammation via suppression of NLRP3 inflammasome

Background

Acne is a chronic facial disease caused by Propionibacterium acnes, which proliferates within sebum-blocked skin follicles and increases inflammatory cytokine production. Several therapeutic drugs and products have been proposed to treat acne, yet no single treatment that ensures long-term treatment efficacy for all patients is available. Here, we explored the use of facial autologous fat transplant of adipose-derived stem cells (ADSCs) to dramatically reduce acne lesions.

Methods

THP-1 cells were treated with active P. acnes for 24 h at different multiplicities of infection, and alterations in inflammatory factors were detected. To study the effect of THP-1 on inflammasome-related proteins, we first co-cultured ADSCs with THP-1 cells treated with P. acnes and evaluated the levels of these proteins in the supernatant. Further, an acne mouse model injected with ADSCs was used to assess inflammatory changes.

Results

Propionibacterium acnes-mediated stimulation of THP-1 cells had a direct correlation with the expression of active caspase-1 and interleukin (IL)-1β in an infection-dependent manner. ADSCs significantly reduced the production of IL-1β induced by P. acnes stimulation through the reactive oxygen species (ROS)/Nod-like receptor family pyrin domain-containing 3 (NLRP3)/caspase-1 pathway. The results showed that ADSCs inhibit the skin inflammation induced by P. acnes by blocking the NLRP3 inflammasome via reducing the secretion of IL-1β in vivo.

Conclusions

Our findings suggest that ADSCs can alter IL-1β secretion by restricting the production of mitochondria ROS, thereby inhibiting the NLRP3/caspase-1 pathway in P. acnes-induced inflammatory responses. This study indicates that anti‐acne therapy can potentially be developed by targeting the NLRP3 inflammasome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03007-7.

Current regenerative medicine-based approaches for skin regeneration: A review of literature and a report on clinical applications in Japan

Current trends indicate a growing interest among healthcare specialists and the public in the use of regenerative medicine-based approaches for skin regeneration. The approaches are categorised in either cell-based or cell-free therapies and are reportedly safe and effective. Cell-based therapies include mesenchymal stem cells (MSCs), tissue induced pluripotent stem cells (iPSCs), fibroblast-based products, and blood-derived therapies, such as those employing platelet-rich plasma (PRP) products. Cell-free therapies primarily involve the use of MSC-derived extracellular vesicles/exosomes. MSCs are isolated from various tissues, such as fat, bone marrow, umbilical cord, menstrual blood, and foetal skin, and expanded ex vivo before transplantation. In cell-free therapies, MSC exosomes, MSC-derived cultured media, and MSC-derived extracellular vesicles are collected from MSC-conditioned media or supernatant. In this review, a literature search of the Cochrane Library, MEDLINE (PubMed), EMBASE, and Scopus was conducted using several combinations of terms, such as ‘stem’, ‘cell’, ‘aging’, ‘wrinkles’, ‘nasolabial folds’, ‘therapy’, ‘mesenchymal stem cells’, and ‘skin’, to identify relevant articles providing a comprehensive update on the different regenerative medicine-based therapies and their application to skin regeneration. In addition, the regulatory perspectives on the clinical application of some of these therapies in Japan are highlighted.

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The use of regenerative medicine-based therapy for skin rejuvenation is expanding.

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Therapies can be categorised as either cell-based or cell-free therapies.

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MSCs can be isolated from various tissues for cosmetic applications.

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MSC-derived exosomes increase skin cell proliferation and migration.

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In Japan, most cell-based treatments carry class II/III regenerative medicine risks.

Effectiveness of Topical Conditioned Medium of Stem Cells in Facial Skin Nonsurgical Resurfacing Modalities for Antiaging: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Facial skin nonsurgical resurfacing modalities, including laser, chemical peeling, and microneedling, have become common due to increasing public concern about skin aging. The potential effect of stem cell conditioned medium (CM) for antiaging has been reported in recent years, and such medium may be able to improve the efficacy of resurfacing modalities. This study investigated the efficacy of topical CM combined with resurfacing in comparison with resurfacing alone. We searched the PubMed, Embase, and Cochrane Library databases for randomized controlled trials (RCTs). We used the Cochrane risk-of-bias tool (version 2) to assess the risk of bias of the included studies and Review Manager (version 5.4) for data analysis. Means and standard deviations of outcomes, namely wrinkle, pigmentation, pore, and overall improvement, were extracted. After screening, we included five RCTs in the analysis, four of which were quantitatively analyzed. The result revealed that stem cell CM significantly reduced wrinkles (P = 0.0006), pigmentation (P = 0.004), and pores (P = 0.01) and improved overall skin condition (P < 0.0001). In summary, we suggest that stem cell CM is a safe treatment that can enhance the efficacy of facial skin nonsurgical resurfacing modalities.Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of Extracellular Vesicles Secreted by TGFβ-Stimulated Umbilical Cord Mesenchymal Stem Cells on Skin Fibroblasts by Promoting Fibroblast Migration and ECM Protein Production

Umbilical cord-derived mesenchymal stem cells (UCMSCs) have been illustrated for their roles in immunological modulation and tissue regeneration through the secretome. Additionally, culture conditions can trigger the secretion of extracellular vesicles (EVs) into extracellular environments with significant bioactivities. This study aims to investigate the roles of three EV sub-populations released by UCMSCs primed with transforming growth factor β (TGFβ) and their capacity to alter dermal fibroblast functions for skin aging. Results show that three EV sub-populations, including apoptotic bodies (ABs), microvesicles (MVs), and exosomes (EXs), were separated from conditioned media. These three EVs carried growth factors, such as FGF-2, HGF, and VEGF-A, and did not express noticeable effects on fibroblast proliferation and migration. Only EX from TGFβ-stimulated UCMSCs exhibited a better capacity to promote fibroblasts migrating to close scratched wounds than EX from UCMSCs cultured in the normal condition from 24 h to 52 h. Additionally, mRNA levels of ECM genes (COL I, COL III, Elastin, HAS II, and HAS III) were detected with lower levels in fibroblasts treated with EVs from normal UCMSCs or TGFβ-stimulated UCMSCs compared to EV-depleted condition. On the contrary, the protein levels of total collagen and elastin released by fibroblasts were greater in the cell groups treated with EVs compared to EV-depleted conditions; particularly elastin associated with TGFβ-stimulated UCMSCs. These data indicate the potential roles of EVs from UCMSCs in protecting skin from aging by promoting ECM protein production.

Factors affecting cell viability and the yield of adipose-derived stromal vascular fraction

The stromal vascular fraction (SVF) is isolated from adipose tissue and has tremendous regenerative potential for proliferation and differentiation. This study aimed to investigate the factors affecting the cell yield and viability of the SVF to improve the outcomes of its clinical applications and enhance its clinical usage. We performed a retrospective analysis with 121 patients who underwent liposuction to harvest adipose-derived SVF. We recorded patient demographic and clinical characteristics, including age, sex, body mass index (BMI), blood type, medical comorbidities, and smoking and alcohol consumption. As for operative variables, we noted the amount of lipoaspirate and the donor areas, including the lower and entire abdomen. The viability and the cell count of SVF were documented. Sex was a statistically significant factor for viability rate (p < 0.015) and cell count (p < 0.009). Men had higher viability, while women had higher cell counts. We found a statistically significant difference in the presence of hypertension (p = 0.024) and alcohol consumption (p = 0.024). There was a statistically significant relationship between cell count and age (p < 0.001), BMI (p = 0.006), and amount of lipoaspirate (p < 0.001). Sex had significant associations with cell count and viability, while age, BMI, and lipoaspirate amount were significantly associated with cell count. Hypertension and alcohol consumption significantly affected cell count, which is the first such report of this association. Surgeons could apply this knowledge to patient selection for optimal treatment outcomes. Additionally, understanding these factors can help manage patient expectations.

Stem Cell-Derived Exosomes: A New Method for Reversing Skin Aging

Senescence is an inevitable natural life process that involves structural and functional degeneration of tissues and organs. Recently, the process of skin aging has attracted much attention. Determining a means to delay or even reverse skin aging has become a research hotspot in medical cosmetology and anti-aging. Dysfunction in the epidermis and fibroblasts and changes in the composition and content of the extracellular matrix are common pathophysiological manifestations of skin aging. Reactive oxygen species and matrix metalloproteinases play essential roles in this process. Stem cells are pluripotent cells that possess self-replication abilities and can differentiate into multiple functional cells under certain conditions. These cells also possess a strong ability to facilitate tissue repair and regeneration. Stem cell transplantation has the potential for application in anti-aging therapy. Increasing studies have demonstrated that stem cells perform functions through paracrine processes, particularly those involving exosomes. Exosomes are nano-vesicular substances secreted by stem cells that participate in cell-to-cell communication by transporting their contents into target cells. In this chapter, the biological characteristics of exosomes were reviewed, including their effects on extracellular matrix formation, epidermal cell function, fibroblast function and antioxidation. Exosomes derived from stem cells may provide a new means to reverse skin aging.

Anti-Aging Effect of the Stromal Vascular Fraction/Adipose-Derived Stem Cells in a Mouse Model of Skin Aging Induced by UVB Irradiation

Adipose-derived stem cells(ADSCs) have been used for anti-photo-aging. But the purification of ADSCs requires in vitro amplification and culture, there is considerable risk of direct treatment for patients. Stromal vascular fraction(SVF) is a biologically and clinically interesting heterogeneous cell population contains ADSCs. There are few reports on anti-aging effects of SVF in photo-aging skin. The present study investigated the anti-aging effect of stromal vascular fraction (SVF) and adipose-derived stem cells (ADSCs) injection in photo-aging skin. The relationship between the dosage of injection and effect was also discussed. Thirty healthy, 6-week-old, nude rats were randomly divided into the control and experimental groups. The experimental group needing ultraviolet B (UVB) irradiation five days per week, and a duration of 8 weeks. According to different dose regimens of SVF and ADSCs, experiment rats were randomly grouped as the model control group, low-dose (LD) treatment group, middle-dose (MD) treatment group and high-dose (HD) treatment group. At 7 and 28 days post-treatment, specimens were harvested for histological and immunohistochemical analysis. We found that certain concentrations of cells (MD and HD groups) could improve the texture of photoaged skin. Changes in the epidermal cell layer were clearly observed after 7 days of treatment. The epidermal layer becomes thinner and more tender. After 28 days of treatment, the dermal tissue was thickened and the collagen content and proportion were improved. All these indicators showed no significant difference between the same dosages in the two treatment groups. Our results demonstrate that SVF may have anti-aging potential in photo-aging skin and the ADSCs play an important role in SVF. SVF maybe a potential agent for photo-anging skin and the most effective dose of SVF was 106 cells /100 µl/injection point. The proper injection interval may be 1.5 cm.

Regenerative effect of combined laser and human stem cell-conditioned medium therapy on hypertrophic burn scar

PURPOSE

This study aimed to determine the effect of combined treatment with non-ablative laser and human stem cell-conditioned medium (HSCM) on tissue regeneration after burn-induced hypertrophic scar (HTS) formation.

METHODS

Fourteen patients with HTSs on both sides of the same body part were subjected to three sessions of non-ablative laser treatment, with an interval of four weeks between each treatment. Following laser treatment, HSCM and normal saline were applied to the HTSs of the right (experimental) and left side (control), respectively. Over the next 6 days, HSCM and moisturizer were applied to experimental scars, while only moisturizer was applied to control scars. Skin characteristics were evaluated before laser treatment and on the seventh day after the third laser treatment.

RESULTS

No significant intergroup differences were noted in the initial evaluation (P > 0.05). We found significant differences between the pre- and post-treatment measurements of erythema (P < 0.001), trans-epidermal water loss (TEWL; P < 0.001), and Cutometer® parameters (all parameters; P <0^.05) of experimental scars. Control scars also showed significant differences between pre- and post-treatment measurements of thickness (P = 0.01), erythema (P < 0.001), TEWL (P < 0.001), and Cutometer® parameters (all parameters; P < 0.05). Changes (pre- to post-treatment) in scar thickness between the experimental (-0.003 ± 0.09) and control scars (0.04 ± 0.12) were significant (P = 0.01).

CONCLUSION

These results suggest that HSCM has a positive effect on short-term results when applied after laser treatment of hypertrophic scars.

Protective roles of mesenchymal stem cells on skin photoaging: A narrative review

Skin is a natural barrier of human body and a visual indicator of aging process. Exposure to ultraviolet (UV) radiation in the sunlight may injure the skin tissues and cause local damage. Besides, it is reported that repetitive or long-term exposure to UV radiation may reduce the collagen production, change the normal skin structure and cause premature skin aging. This is termed "photoaging". The classical symptoms of photoaging include increased roughness, wrinkle formation, mottled pigmentation or even precancerous changes. Mesenchymal stem cells (MSCs) are a kind of cells with the ability of self-renewal and multidirectional differentiation into many types of cells, like adipocytes, osteoblasts and chondrocytes. Researchers have explored diverse pharmacological actions of MSCs because of their migratory activity, paracrine actions and immunoregulation effects. In recent years, the huge potential of MSCs in preventing skin from photoaging has gained wide attention. MSCs exert their beneficial effects on skin photoaging via antioxidant effect, anti-apoptotic/anti-inflammatory effect, reduction of matrix metalloproteinases (MMPs) and activation of dermal fibroblasts proliferation. MSCs and MSC related products have demonstrated huge potential in the treatment of skin photoaging. This narrative review concisely sums up the recent research developments on the roles of MSCs in protection against photoaging and highlights the enormous potential of MSCs in skin photoaging treatment.

A Temperature-Based Easy-Separable (TempEasy) 3D Hydrogel Coculture System

Interactions between different cell types are crucial for their behavior in tissues, but are rarely considered in 3D in vitro cell culture experiments. One reason is that such coculture experiments are sometimes difficult to perform in 3D or require specialized equipment or know-how. Here, a new 3D cell coculture system is introduced, TempEasy, which is readily applied in any cell culture lab. The matrix material is based on polyisocyanide hydrogels, which closely resemble the mechanical characteristics of the natural extracellular matrix. Gels with different gelation temperatures, seeded with different cells, are placed on top of each other to form an indirect coculture. Cooling reverses gelation, allowing cell harvesting from each layer separately, which benefits downstream analysis. To demonstrate the potential of TempEasy , human adipose stem cells (hADSCs) with vaginal epithelial fibroblasts are cocultured. The analysis of a 7-day coculture shows that hADSCs promote cell-cell interaction of fibroblasts, while fibroblasts promote proliferation and differentiation of hADSCs. TempEasy provides a straightforward operational platform for indirect cocultures of cells of different lineages in well-defined microenvironments.

Efficiency assessment of irrigation as an alternative method for improving the regenerative potential of nonhealing wounds

The application of mesenchymal stem/stromal cells (MSC) in regenerative medicine offers hope for the effective treatment of incurable or difficult‐to‐heal diseases. However, it requires the development of unified protocols for both safe and efficient cell acquisition and clinical usage. The therapeutic effect of fat grafts (containing stem cells) in non‐healing wounds has been discussed in previous studies, although the application requires local or general anaesthesia. The treatment of MSC derived from adipose tissue (ASC) could be a less invasive method, and efficient delivery could lead to more favourable outcomes, which should encourage clinicians to use such therapeutic approaches more frequently. Therefore, the aim of this study was to optimise the methods of ASC isolation, culture and administration while maintaining their high survival, proliferation and colonisation potential. The ASC were isolated by an enzymatic method and were characterised according to International Society for Cellular Therapy and International Federation for Adipose Therapeutics and Science guidelines. To assess the opportunity to obtain a sufficient number of cells for transplantation, long‐term cell cultures in two oxygen concentrations (5% vs. 21%) were conducted. For these cultures, the population doubling time, the cumulative time for cell population doublings and the rate of cell senescence were estimated. In a developed and pre‐defined protocol, ASC can be efficiently cultured at physiological oxygen concentrations (5%), which leads to faster proliferation and slower cell senescence. Subsequently, to select the optimal and minimally invasive methods of ASC transplantation, direct cell application with an irrigator or with skin dressings was analysed. Our results confirmed that both the presented methods of cell application allow for the safe delivery of isolated ASC into wounds without losing their vitality. Cells propagated in the described conditions and applied in non‐invasive cell application (with an irrigation system and dressings) to treat chronic wounds can be a potential alternative or supplement to more invasive clinical approaches.

Protective Effect of Fat-Tissue-Derived Products against Ultraviolet Irradiation-Induced Photoaging in Mouse Skin

BACKGROUND

Exposure to ultraviolet radiation causes erythema, inflammation, and photoaging. Mechanical micronization of adipose tissue can concentrate functional cells and has great potential as an alternative for regenerative medicine. Stromal vascular fraction gel is produced by means of a series of mechanical processes of lipoaspirates and can be injected intradermally. This study aimed to assess the therapeutic effect of stromal vascular fraction gel on photoaging skin.

METHODS

A photoaging model was established in nude mice. Photoaging mice received treatments of stromal vascular fraction gel, fat, tretinoin, or phosphate-buffered saline. Photoaging skin was characterized by histologic and immunohistochemical analyses. Expression of collagen synthesis-related or photoaging-related genes was assessed.

RESULTS

Stromal vascular fraction gel, fat, and tretinoin reversed photoaging, whereas stromal vascular fraction gel demonstrated the greatest therapeutic effect. Treatment with stromal vascular fraction gel restored intradermal fat tissue content and increased dermal collagen density. Injection of stromal vascular fraction gel had the strongest effect on stimulating fibroblasts and increasing the expression of transforming growth factor β1 (TGF-β1), propeptide of type-I procollagen, and Smad 2, decreasing the expression of Smad 3, compared with fat and tretinoin. Expression of photoaging-related genes was significantly reduced, whereas expression of fibulin-5 was significantly increased after stromal vascular fraction gel treatment.

CONCLUSIONS

Stromal vascular fraction gel demonstrated remarkable therapeutic effects in reversing photoaging skin. Stromal vascular fraction gel can be injected intradermally and survive within dermal layer after grafting. This product increased TGF-β1expression and activated fibroblasts to produce propeptide of type I procollagen, thus increasing the amount of collagen I, leading to thickening of the dermis of photoaging skin.

Evaluating the effect of Luffa cylindrica stem sap on dermal fibroblasts; An invitro study

Luffa cylindrica stem sap (LuCS) has been traditionally used as a facial cosmetic supplement to enhance the skin condition of Asians. However, LuCS has yet to be described and there is no solid scientific evidence regarding the use of LuCS as an anti-wrinkle agent. In the present study, we have evaluated the functional effect of LuCS and its underlying mechanisms based on scientific evidence. Treatment with LuCS stimulated the growth and migration of human skin fibroblasts. LuCS treatment activated EGFR signaling via the enhanced expression of EGFR and down-regulation of PPARγ in human skin fibroblasts. Exposure to LuCS induced the synthesis of cellular type I procollagen and elastin in consort with the down-regulation of various proteinases including MMP-1, -2 and -9 in human skin fibroblasts. LuCS treatment also reversed the skin damage induced by UV-A irradiation in human skin fibroblasts. 3-bromo-3-methylisoxazol-5-amine was identified as the functional component using UPLC-MS-MS analysis and increased production of cellular type I procollagen. Collectively, these results suggest the efficacy of LuCS supplementation in improving the skin condition via anti-wrinkle effect.

Mesenchymal Stem Cell Secretome for Dermatology Application: A Review

Secretome, also known as conditioned medium, is a secreted molecule from mesenchymal stem cells (MSCs) that has a variety of biological activities that can be used in various therapies, especially on the skin applications. A lack of conventional therapies makes secretome as a promising alternative therapy. The presence of growth factors, cytokines, and extracellular vesicles including microvesicles and exosomes in secretome has been widely reported, which serves in improving the proliferation and migration of cells to help in skin regeneration. Therefore, we were able to optimize the use of this secretome in a well-needed special review related to its work in addressing various skin problems. So, in this article, we discussed the benefits and biological activity of secretome on the skin application. This review was compiled based on the approval of several sites, such as Scopus, PubMed, Science Direct, and Google Scholar with the terms "MSC secretome for skin," "secretome for skin," "secretome dermatology," "secretome conditioned medium for skin," "secretome conditioned medium for skin wound," "secretome conditioned medium for aging," "secretome conditioned medium for hair growth," and "secretome conditioned medium for psoriasis." A total of 215 articles were collected for selection, of which 90 articles were used. Based on the results, it was concluded that secretome has a variety of useful activities to regenerate and repair tissue damage that have not been used on the skin, such as for wound healing, photoprotection, promotion of hair growth, psoriasis treatment, and other application as antimicrobial.

Adipose-Derived Stem Cell Conditioned Medium and Wound Healing: A Systematic Review

Adipose-derived stem cells (ASCs) have been growing in popularity for their potential in wound healing and tissue engineering. Stem cell therapies are limited in application, with the need to maintain cell viability and function as well as safety concerns. It has been increasingly reported that the effects of ASCs are predominantly attributable to the paracrine effects of the secreted factors, which can be collected in conditioned medium (CM). The goal of this systematic review is to investigate the effects on wound healing of CM collected from ASC culture. Original articles relevant to ASC-CM and wound healing (in vitro: dermal fibroblast, epidermal keratinocytes and their equivalent cell lines; in vivo: full-thickness wound models) were included. The agreement level of selections between two investigators were calculated by the kappa scores. And the information concerning to the publications, CM preparation and its application and effects were extracted and reported in a systematic way and summarized in tables. In total, 121 publications were initially identified through a search of the PubMed/MEDLINE database with a specific search algorithm, and 36 articles were ultimately included after two screenings. Nineteen were in vitro studies that met the search criteria and 17 were in vivo studies with or without in vitro data. In summary, based on the included articles, treatment with ASC conditioned medium (ASC-CM), to a large extent, resulted in positive effects on wound healing in vitro and in vivo. Modulation of the culture conditions of ASCs producing the CM, including hypoxic conditions, alternative substrates, medium supplementation, as well as genetic modification of cells, favorably promoted the effects of ASC-CM. Finally, a discussion of the future perspectives and therapeutic potential of ASC-CM, which also addresses the limitations of the field, is presented. A limitation of the evidence is the inconsistency in CM preparation methods among included articles. In conclusion, ASC-CM is a promising novel cell-free therapy for wound healing in regenerative medicine and warrants further exploration.

Effects of human collagen α-1 type I-derived proteins on collagen synthesis and elastin production in human dermal fibroblasts

Collagen type I is the most abundant form of collagen in human tissues, and is composed of two identical α-1 type I chains and an α-2 type I chain organized in a triple helical structure. A previous study has shown that human collagen α-2 type I (hCOL1A2) promotes collagen synthesis, wound healing, and elastin production in normal human dermal fibroblasts (HDFs). However, the biological effects of human collagen α-1 type I (hCOL1A1) on various skin properties have not been investigated. Here, we isolate and identify the hCOL1A1-collagen effective domain (CED) which promotes collagen type I synthesis. Recombinant hCOL1A1-CED effectively induces cell proliferation and collagen biosynthesis in HDFs, as well as increased cell migration and elastin production. Based on these results, hCOL1A1-CED may be explored further for its potential use as a preventative agent against skin aging.

Stem cell therapy in dermatology

Stem cells are precursor cells present in many tissues with ability to differentiate into various types of cells. This interesting property of plasticity can have therapeutic implications and there has been substantial research in this field in last few decades. As a result, stem cell therapy is now used as a therapeutic modality in many conditions, and has made its way in dermatology too. Stem cells can be classified on the basis of their source and differentiating capacity. In skin, they are present in the inter-follicular epidermis, hair follicle, dermis and adipose tissue, which help in maintaining normal skin homeostasis and repair and regeneration during injury. In view of their unique properties, they have been employed in treatment of several dermatoses including systemic sclerosis, systemic lupus erythematosus, scleromyxedema, alopecia, Merkel cell carcinoma, pemphigus vulgaris, psoriasis, wound healing, epidermolysis bullosa and even aesthetic medicine, with variable success. The advent of stem cell therapy has undoubtedly brought us closer to curative treatment of disorders previously considered untreatable. Nevertheless, there are multiple lacunae which need to be addressed including ideal patient selection, timing of intervention, appropriate conditioning regimens, post-intervention care and cost effectiveness. Further research in these aspects would help optimize the results of stem cell therapy.

A Step in the Right Direction: A Prospective Randomized, Controlled Crossover Trial of Autologous Fat Grafting for Rejuvenation of the Heel

BACKGROUND

The shock-absorbing soft tissues of the heel are composed of dermis and specialized fat pads. Heel fat pad atrophy is common and can be painful and debilitating. In our previous work, autologous fat grafting was effective for treating pain from forefoot fat pad atrophy.

OBJECTIVES

The authors hypothesized that autologous fat grafting to the heel would relieve pain and improve function in patients with heel fat pad atrophy.

METHODS

Patients with heel fat pad atrophy and associated pain were recruited and randomized into 2 groups. Group 1 received autologous fat grafting on enrollment and was followed for 2 years. Group 2 received offloading and activity modification for 1 year, then crossed over, underwent autologous fat grafting, and was followed for 1 year afterward. Outcome measures included ultrasound-measured fat pad and dermal thickness; pedobarograph-measured foot pressures and forces; and patient-reported outcomes as measured by the Manchester Foot Pain and Disability Index.

RESULTS

Thirteen patients met the inclusion criteria and completed the study. Seven (12 affected feet) were randomized into Group 1; and 6 (9 affected feet) were randomized into Group 2. The average age was 55 years and BMI was 30.5 kg/m2. Demographics did not significantly differ between groups. Heel fat pad thickness increased after autologous fat grafting but returned to baseline at 6 months. However, autologous fat grafting increased dermal thickness significantly and also increased fat pad thickness under a compressive load compared with controls at 6 and 12 months. Foot pain, function, and appearance were also significantly improved compared with controls at 6 and 12 months.

CONCLUSIONS

Autologous fat grafting improved patient-reported foot pain, function, and appearance and may rejuvenate local soft tissues in patients with heel fat pad atrophy.

LEVEL OF EVIDENCE: 3

Comparison of the Donor Age-Dependent and In Vitro Culture-Dependent Mesenchymal Stem Cell Aging in Rat Model

Clinical experiments suggest that mesenchymal stem cells (MSCs) may be useful for tissue repair therapies or treatment of the autoimmune disorders. There is still lack of consensus concerning the age limit of MSC donors, majority of researchers suggest the autologous MSC therapies of patients not exceeding age limit of 55-60 yrs. The purpose of our study was to compare the selected parameters of MSCs from adipose tissue (adipose stem cell, ASC) collected from young and old rats of ages corresponding to patient's ages 25 yrs. and 80 yrs., respectively. The differences of parameters of ASCs from young and old animals were compared with the differences between ASCs from short-term (3 passage) and long-term (30 passage) in vitro culture. Cell morphology, surface marker expression, growth potential, metabolic activity, β-galactosidase activity, clonogenic potential, angiogenic potential, and differentiation ability of ASCs from young and aged animals and from in vitro cultures at 3rd and 30th passages were compared and analyzed. It may be concluded that ASCs may be applied for autologous transplantations in aged patients. Comparison of ASC aging dynamics depending on host aging or in vitro culture duration suggests that long-term in vitro culture may affect ASCs more than natural aging process of their host. We suggest that ASCs expanded in vitro prior to their clinical use must be carefully screened for the possible aging effects resulting not only from donor age, but from the duration of their in vitro culture.

Hydrogel Scaffolds to Deliver Cell Therapies for Wound Healing

Cutaneous wounds are a growing global health burden as a result of an aging population coupled with increasing incidence of diabetes, obesity, and cancer. Cell-based approaches have been used to treat wounds due to their secretory, immunomodulatory, and regenerative effects, and recent studies have highlighted that delivery of stem cells may provide the most benefits. Delivering these cells to wounds with direct injection has been associated with low viability, transient retention, and overall poor efficacy. The use of bioactive scaffolds provides a promising method to improve cell therapy delivery. Specifically, hydrogels provide a physiologic microenvironment for transplanted cells, including mechanical support and protection from native immune cells, and cell-hydrogel interactions may be tailored based on specific tissue properties. In this review, we describe the current and future directions of various cell therapies and usage of hydrogels to deliver these cells for wound healing applications.

Tissue Mechanics in Haired Murine Skin: Potential Implications for Skin Aging

During aging, the skin undergoes changes in architecture and composition. Skin aging phenotypes occur due to accumulated changes in the genome/epigenome, cytokine/cell adhesion, cell distribution/extracellular matrix (ECM), etc. Here we review data suggesting that tissue mechanics also plays a role in skin aging. While mouse and human skin share some similarities, their skin architectures differ in some respects. However, we use recent research in haired murine skin because of the available experimental data. Skin suffers from changes in both its appendages and inter-appendage regions. The elderly exhibit wrinkles and loose dermis and are more likely to suffer from wounds and superficial abrasions with poor healing. They also have a reduction in the number of skin appendages. While telogen is prolonged in aging murine skin, hair follicle stem cells can be rejuvenated to enter anagen if transplanted to a young skin environment. We highlight recent single-cell analyses performed on epidermis and aging human skin which identified new basal cell subpopulations that shift in response to wounding. This may be due to alterations of basement membrane stiffness which would change tissue mechanics in aging skin, leading to altered homeostatic dynamics. We propose that the extracellular matrix (ECM) may play a key role as a chemo-mechanical integrator of the multi-layered senescence-associated signaling pathways, dictating the tissue mechanical landscape of niche microenvironments in aging phenotypes. We show examples where failed chemo-mechanical signaling leads to deteriorating homeostasis during skin aging and suggest potential therapeutic strategies to guide future research to delay the aging processes.

Stem cells and growth factors-based delivery approaches for chronic wound repair and regeneration: A promise to heal from within

The sophisticated chain of cellular and molecular episodes during wound healing includes cell migration, cell proliferation, deposition of extracellular matrix, and remodelling and are onerous to replicate. Encapsulation of growth factors (GFs) and Stem cell-based (SCs) has been proclaimed to accelerate healing by transforming every phase associated with wound healing to enhance skin regeneration. Therapeutic application of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs) and induced pluripotent stem cells (PSCs) provides aid in wound fixing, tissue integrity restoration and function of impaired tissue. Several scientific studies have established the essential role GFs in wound healing and their reduced degree in the chronic wound. The overall limitation includes half-life, unfriendly microhabitat abundant with protease, and inadequate delivery approaches results in decreased delivery of effective amounts in a suitable time-based fashion. Advancements in the area of reformative medicine as well as tissue engineering have offered techniques competent of dispensing SCs and GFs in site-oriented manner. The progress in nanotechnology-based approaches attracts researcher to study and evaluate the potential of this SCs and GFs based therapy in chronic wounds. These techniques embrace the polymeric regime viz., nano-formulations, hydrogels, liposomes, scaffolds, nanofibers, metallic nanoparticles, lipid-based nanoparticles and dendrimers that have established better retort through targeting tissues when GFs and SCs are transported via these humans made devices. Assumed the current problems, improvements in delivery approaches and difficulties offered by chronic wounds, we hope to show that encapsulation of SCs and GFs loaded nanoformulations therapies is the rational next step in improving wound care.

The Paracrine Effect of Adipose-Derived Stem Cells Orchestrates Competition between Different Damaged Dermal Fibroblasts to Repair UVB-Induced Skin Aging

Background

Human dermal fibroblasts (HDFs) are the primary cells in skin and are associated with UVB-induced skin photoaging. Adipose-derived stem cells (ASCs) have been proposed as a treatment for skin aging. The goal of this study was to investigate paracrine mechanisms by which ASCs repair HDFs damage from UVB exposure.

Methods

ASCs were cocultured with UVB-irradiated and nonirradiated HDFs. We compared HDF senescence, proliferation, migration, oxidative stress, and cytokine expression. In a nude mouse UVB-induced photoaging model, ASCs were injected subcutaneously, and skin samples were collected weekly between postoperative weeks 3 through 7. Histological analysis, PCR, ELISA, and immunohistochemistry were used to analyze the effect of ASCs.

Results

Compared with UVB-irradiated HDFs, nonirradiated HDFs showed higher proliferation and migration, reduced apoptosis, and fewer senescent cells when cocultured with ASCs. The expression of extracellular matrix-related cytokines was also regulated by ASCs. In addition, ASCs effectively reversed UVB-induced skin photoaging in vivo. We propose that ASCs more robustly coordinate healthy HDFs than UVB-damaged HDFs to repair aging skin.

Conclusions

ASCs improved the function of both UVB-damaged and healthy HDFs through paracrine effects. However, the impact of ASCs on healthy HDFs was greater than UVB-damaged HDFs. These findings help to elucidate the underlying mechanisms of the skin rejuvenation effect of ASCs.

Sequential Scalp Assessment in Hair Regeneration Therapy Using an Adipose-Derived Stem Cell-Conditioned Medium

BACKGROUND

An adipose-derived stem cell-conditioned medium (ADSC-CM) reportedly exerts skin-rejuvenating and hair growth-promoting effects. In the therapeutic application of ADSC-CM for alopecia, changes to the interfollicular scalp remain unclear although some evidence has indicated hair growth-promoting effects.

OBJECTIVE

To evaluate the effects of ADSC-CM not only on hair follicles, but also on the interfollicular scalp.

METHODS

Forty patients (21 men, 19 women; age range, 23-74 years) with alopecia were treated by intradermal injection of ADSC-CM every month for 6 months. Eighty fixed sites on patients were investigated by trichograms, physiological examinations, and ultrasonographic examinations at 4 time points (before treatment and 2, 4, and 6 months after the initial treatment).

RESULTS

Hair density and anagen hair rate increased significantly. As physiological parameters, transepidermal water loss value gradually increased, with significant differences at 4 and 6 months after the initial treatment, but hydration state of the stratum corneum and skin surface lipid level showed no obvious changes. As ultrasonographic parameters, dermal thickness and dermal echogenicity were increased significantly.

CONCLUSION

Intradermal administration of ADSC-CM on the scalp has strong potential to provide regenerative effects for hair follicles and the interfollicular scalp. An adipose-derived stem cell-conditioned medium offers a promising prospect as an alternative treatment for alopecia.

Application of adipose-derived stem cells in photoaging: basic science and literature review

Photoaging is mainly induced by continuous exposure to sun light, causing multiple unwanted skin characters and accelerating skin aging. Adipose-derived stem cells(ADSCs) are promising in supporting skin repair because of their significant antioxidant capacity and strong proliferation, differentiation, and migration ability, as well as their enriched secretome containing various growth factors and cytokines. The identification of the mechanisms by which ADSCs perform these functions for photoaging has great potential to explore therapeutic applications and combat skin aging. We also review the basic mechanisms of UV-induced skin aging and recent improvement in pre-clinical applications of ADSCs associated with photoaging. Results showed that ADSCs are potential to address photoaging problem and might treat skin cancer. Compared with ADSCs alone, the secretome-based approaches and different preconditionings of ADSCs are more promising to overcome the current limitations and enhance the anti-photoaging capacity.

Human collagen alpha-2 type I stimulates collagen synthesis, wound healing, and elastin production in normal human dermal fibroblasts (HDFs)

Skin aging appears to be the result of overlapping intrinsic (including genetic and hormonal factors) and extrinsic (external environment including chronic light exposure, chemicals, and toxins) processes. These factors cause decreases in the synthesis of collagen type I and elastin in fibroblasts and increases in the melanin in melanocytes. Collagen Type I is the most abundant type of collagen and is a major structural protein in human body tissues. In previous studies, many products containing collagen derived from land and marine animals as well as other sources have been used for a wide range of purposes in cosmetics and food. However, to our knowledge, the effects of human collagen-derived peptides on improvements in skin condition have not been investigated. Here we isolate and identify the domain of a human COL1A2-derived protein which promotes fibroblast cell proliferation and collagen type I synthesis. This human COL 1A2-derived peptide enhances wound healing and elastin production. Finally, the human collagen alpha-2 type I-derived peptide (SMM) ameliorates collagen type I synthesis, cell proliferation, cell migration, and elastin synthesis, supporting a significant anti-wrinkle effect. Collectively, these results demonstrate that human collagen alpha-2 type I-derived peptides is practically accessible in both cosmetics and food, with the goal of improving skin condition.

Randomized controlled study for the anti-aging effect of human adipocyte-derived mesenchymal stem cell media combined with niacinamide after laser therapy

BACKGROUND

Recent advancements in laser-assisted drug delivery have emphasized the importance of post-laser use of active ingredients.

AIMS

We evaluated the effect of topical post-laser treatment with adipocyte-derived stem cell-containing medium (ADSC-CM) in combination with niacinamide through a double-blind, randomized, vehicle-controlled study.

PATIENTS/METHODS

Twenty-five patients with aging skin underwent ablative fractional laser (AFL) treatment on both sides of the face for skin rejuvenation. Moisturizers with or without ADSC-CM plus 2% niacinamide was applied to the designated sides of faces for 3 weeks. The wrinkle and the melanin indices were assessed using a specialized digital photography analyzer. Additional in vitro assays were performed.

RESULTS

The wrinkle index, melanin index, patient satisfaction score, and the investigator's global esthetic improvement scale (GAIS) after use of ADSC-CM plus niacinamide were significantly higher than after use of the vehicle cream. The in vitro UVB irradiation assays with human keratinocytes showed decreased levels of pro-inflammatory cytokines upon incubation with ADSC-CM plus niacinamide, and the cell scratch assay displayed decreased MMP-1 and MMP-2 expression as well as increased Type 1 collagen expression.

CONCLUSIONS

We demonstrated that post-laser topical application of ADSC-CM in combination with niacinamide has anti-aging effect on skin.

The Efficacy of Amniotic Membrane Stem Cell (AMSC) Metabolite Product and Vitamin E for Wrinkles, Spots, and Pores in Photoaging

Background

It is expected that a combination of amniotic membrane stem cell metabolite product (AMSC-MP) and vitamin E after fractional CO₂ laser as laser-assisted drug delivery (LADD) will provide better effects in photoaging treatment as the combination reaches the target. This promises an option for photoaging therapy in the future.

Materials and Methods

Sixty women with photoaged skins were involved in this experimental study. They were then divided into two groups. The treatment group received a topical combination of AMSC-MP and vitamin E, and the control group received AMSC-MP alone after fractional CO₂ laser. The treatment was repeated three times.

Result

The Janus assessment results showed a significant difference in pores in the third observation, and the average pore improvements in the treatment group were better than the control group. Wrinkle, UV spot, and polar spot did not show any significant difference.

Conclusion

A combination of the amniotic membrane stem cell metabolite product (AMSC-MP) and vitamin E after fractional CO₂ laser as LADD only improves pores in photoaged skins.

Astragaloside IV Promotes Antiphotoaging by Enhancing the Proliferation and Paracrine Activity of Adipose-Derived Stem Cells

Photoaging is a degenerative biological process. As a kind of pluripotent stem cells, adipose-derived stem cells (ADSCs) are widely used in the treatment of photoaging. Therefore, we aimed to find an effective way to improve the antiaging ability of ADSCs. In this study, we isolated ADSCs and assessed multilineage differentiation ability and markers. Cultured ADSCs were preconditioned with astragaloside IV (ASI) at 10^-7, 10^-6, and 10^-5 M. Cell proliferation was assessed by CCK-8 assay and cytokine secretion by enzyme-linked immunosorbent assay (ELISA). A fibroblast photoaging model was established and cocultured with normal ADSCs or ASI-treated ADSCs. Matrix metalloproteinase-1 (MMP1) and type I procollagen (PC-I) secreted by human dermal fibroblasts were measured by ELISA. The effects of ASI-treated ADSCs on skin texture, including dermal thickness, collagen content, and microvessel density, in a photoaging animal model were analyzed using H&E staining, Masson staining, and CD31 immunohistochemistry, respectively. We found that 10^-6 M ASI could significantly promote cell proliferation and stimulate robust secretion of growth factors in ADSCs. Furthermore, our data showed that ASI-treated ADSCs could markedly reverse the ultraviolet B-induced decrease of PC-I secretion and increase of MMP-1 release in fibroblasts. Moreover, in photoaged skin of nude mice, ASI-treated ADSCs significantly increased dermal thickness, collagen content, and microvessel density.

Facial rejuvenation using stem cell conditioned media combined with skin needling: A split-face comparative study

BACKGROUND

The use of stem cells derived growth factors is representing a novel treatment modality in facial rejuvenation. Nowadays, skin needling is considered a very famous treatment of skin aging. However, the addition of such derived products, augments its therapeutic efficacy in the management and delay of skin aging.

OBJECTIVE

Comparing the effect of amniotic fluid mesenchymal stem cell derived conditioned media (AF-MSC-CM) combined with skin needling versus the needling alone in the management of facial aging.

METHODS

Both sides of the face of ten volunteers, suffering from facial aging, were treated with five sessions of skin needling, 2 weeks apart. After skin microneedling, AF-MSC-CM was added topically to the right side only. Clinical, histological, and morphometrical assessment of the treated skin was done at 1 month after the last session.

RESULTS

The percentage of improvement of aged skin increased significantly on the combined treated side (AF-MSC-CM and dermaroller [DR]), when compared with the other side (DR only) (P < .001). Remodeling of the dermal structures was observed mainly on the combined side. Meanwhile, histometry of the epidermis revealed a significant increase in the epidermal thickness on both treated sides.

CONCLUSION

AF-MSC-CM combined with skin needling was more efficient in managing facial aging than skin needling alone.

Tissue engineering in female pelvic floor reconstruction

Pelvic organ prolapse is a common and frequently occurring disease in middle-aged and elderly women. Mesh implantation is an ideal surgical treatment. The polypropylene mesh commonly used in clinical practice has good mechanical properties, but there are long-term complications. The application of tissue engineering technology in the treatment of pelvic organ prolapse disease can not only meet the mechanical requirements of pelvic floor support, but also be more biocompatible than traditional polypropylene mesh, and can promote tissue repair to a certain extent. In this paper, the progress of tissue engineering was summarized to understand the application of tissue engineering in the treatment of pelvic organ prolapse disease and will help in research.