The study of the whole bladder acellular matrix prepared by the perfusion decellularization system combined with the adipose-derived stem cells to construct the tissue engineering bladder / 中华泌尿外科杂志

Objective:To prepare the whole bladder acellular matrix (BAM) using the self-designed perfusion decellularization system, and evaluate the feasibility of constructing the tissue engineering bladder with the adipose-derived stem cells (ADSCs).Methods:This study was conducted from October 2020 to April 2021. The self-designed perfusion decellularization system was used, and four different decellularization protocols (group A, group B, group C and group D) were formulated, according to the flow direction of the perfusate and the action time of different decellularization solutions. Among them, the urethral orifice of the bladder tissue was used as the outflow tract of the perfusion fluid in groups A and B. The top of the bladder was cut off and used as the outflow tract of the perfusion fluid in groups C and D. In groups A and C, 1% Triton X-100 was treated for 6 h, and 1% sodium dodecyl sulfate (SDS) was treated for 2 h. In groups B and D, 1% Triton X-100 was treated for 7 h, and 1% sodium dodecyl sulfate (SDS) was treated for 1 h. In addition, the tissue in the normal bladder group was directly obtained from the natural bladder tissue, which did not require perfusion, cryopreservation and thawing. The fast and efficient decellularization protocol was screened out through HE, DAPI, Masson trichrome and Alcian Blue staining and quantitative analyses to prepare the whole bladder scaffold. The prepared BAM was used as the scaffold material, and the ADSCs were used as the seeding cells to construct the tissue engineering bladder. HE and DAPI staining were used to observe the distribution of ADSCs on the BAM.Results:HE and DAPI staining showed that there was no obvious nuclear residue in the group C. Masson trichrome and Alcian Blue staining showed that the collagen structure and glycosaminoglycan were well preserved in the group C. There was no significant difference in bladder wall thickness between the group C and the normal bladder group [(975.44±158.62)μm vs.(1 064.49±168.52)μm, P > 0.05]. The DNA content in the group C [(43.59 ±4.59) ng/mg] was lower than that in the normal bladder group, group A, group B and group D [(532.50±26.69), (135.17±6.99), (182.49±13.69) and(84.00±4.38)ng/mg], and the difference was statistically significant ( P<0.05). The collagen content [(10.98 ± 0.29)μg/mg] and glycosaminoglycan content [(2.30±0.18)μg/mg] in group C were not significantly different with those in the normal bladder group [(11.69±0.49) and (2.36±0.09)μg/mg, P>0.05]. Scanning electron microscopy showed that a large number of pore structures could be observed on the surface of the prepared BAM in groups A-D and were facilitated to cell adhesion. The isolated and cultured ADSCs were identified by flow cytometry to confirm the positive expression of CD90 and CD29, and the negative expression of CD45 and CD106. Live/dead staining and CCK-8 detection confirmed that the prepared BAM in the group C had no cytotoxicity. HE and DAPI staining showed that a large number of ADSCs were distributed on the surface and inside of the tissue engineering bladder. Conclusions:The whole bladder shape BAM prepared by the self-designed perfusion decellularization system could be used as the scaffold material for bladder tissue engineering, and the constructed tissue engineering bladder could be used for bladder repair and reconstruction.

The study on the tissue engineered bladder patch constructed with the double-layer silk scaffold and adipose-derived stem cells for bladder repair and reconstruction / 中华泌尿外科杂志

Objective:To investigate the effect of tissue engineered bladder patch constructed by double-layer silk scaffold and adipose-derived stem cells (ADSCs) in the repair and reconstruction of bladder.Methods:This study was conducted from May 2020 to March 2021. The silk fibroin (SF) aqueous solution was obtained from silkworm cocoons, and a double-layer silk scaffold composed of silk fibroin film and silk fibroin sponge was further prepared. The rat ADSCs were isolated, cultured, and the ADSCs surface markers (CD29, CD90, CD45, CD106) were identified by flow cytometry. The ADSCs were planted on a double-layer silk scaffold to construct a tissue-engineered bladder patch. Thirty-six male SD rats were randomly divided into three groups: tissue engineered bladder patch group (SF-ADSCs group, n=15), double-layer silk scaffold group (SF group, n=15), control group ( n=6). The tissue engineered bladder patch (SF-ADSCs group) and double-layer silk scaffold (SF group) were wrapped on the omentum to promote vascularization. The vascularization was evaluated by HE and immunofluorescence staining. The wrapped tissue engineered bladder patch and double-layer silk scaffold were used to repair the defective bladder. In the control group (six rats), the incision was closed immediately after the bladder tissue fully exposed. At 4 weeks and 12 weeks after operation, the general morphology of bladder tissue and cystography were performed to evaluate the recovery of bladder morphology. After the graft was harvested, HE and Masson's trichrome staining and immunofluorescence staining were used to observe the regeneration of bladder wall tissue. Urodynamics was used to assess the recovery of bladder function at 12 weeks after operation. Results:The flow cytometry results confirmed that the isolated cells positively expressed CD29 and CD90, and there was no significant expression of CD45 and CD106. Gross observation and scanning electron microscope confirmed that the preparation of double-layer silk scaffold not only had a pore structure that was conducive to cell planting, but also had good toughness and was facilitated to surgical suture. The number (43.50±2.66) and area (0.73±0.03)% of vascular-like structures in the SF-ADSCs group after the omentum encapsulation was significantly higher than that in the SF group [(24.50±3.51), (0.55±0.05)%], and the difference was statistically significant ( P<0.05). At 4 weeks after bladder repair, the histological staining of the grafts in the SF-ADSCs and SF groups showed a large number of degraded fragments of double-layer silk scaffold. At 12 weeks, the morphology of the graft in the SF-ADSCs group showed uniform bladder morphology, which was similar to that of normal bladder tissue. Immunofluorescence staining showed that the continuous urothelial layer, abundant smooth muscle tissue, vascular structure and regenerated neurons could be observed in the SF-ADSCs group. Urodynamic test showed that the bladder maximum volume (0.74±0.03)ml and compliance (16.68±0.44)μl/cm H 2O in the SF-ADSCs group, which were better than that in the SF group [(0.47±0.05)ml, (14.89±0.37)μl/cm H 2O], but lower than that in the control group [(1.12±0.08)ml, (19.34±0.45)μl/cm H 2O], and the difference was statistically significant ( P<0.05). Conclusions:The tissue engineered bladder patch constructed with double-layer silk scaffolds and ADSCs could promote the morphological repair of bladder tissue, the regeneration of bladder wall structure and the recovery of bladder physiological function.

Comparison of two different levels of adipose derived stem cells in fat transplantation in nude mice / 中华医学美学美容杂志

Objective:To explore the mechanism of fat formation induced by PLA-adipose derived stem cells (ADSC) and LAF-ADSC cells, and to provide a new direction and idea for cell-assisted granular fat transplantation.Methods:The liposuction operation of normal human body was performed in the plastic surgery operating room of Chengdu Badachu Medical Cosmetic Hospital. The liposuction obtained through the operation was placed still, and the upper granular adipose tissue was digested, isolated, cultured and identified by PLA-ADSC; the obtained lower liquid tissue was centrifuged, and the precipitate was digested, isolated, cultured and identified by LAF-ADSC; the differentiation characteristics and growth ability of PLA-ADSC and LAF-ADSC were compared. Then animal experiments were carried out: PLA-ADSC and LAF-ADSC were mixed with matrix glue Matrigel and transplanted into nude mice as experimental group 1 and experimental group 2. Matrix glue Matrigel was transplanted into nude mice as control group. The lipogenic ability of the three groups in nude mice was compared.Results:The cell experiment showed that the cells extracted from the static granular fat and the lower filtrate sediment could adhere to the wall and grew and subcultured smoothly. The cells from the above two different sources expressed CD44, CD73 and CD105, with positive rates of 99.5%, 99.99% and 99.7% respectively, while CD19, CD31 and CD45 were negative. The results of lipogenic induction and differentiation showed that there were lipid droplets in the cytoplasm, and the lipid droplets were orange red after cell oil red O staining. The results of animal experiment showed that three months after transplantation, the average graft volume of experimental group 1 was (0.070±0.009) cm 3, that of experimental group 2 was (0.067±0.007) cm 3, and that of the control group was (0.009±0.005) cm 3. The difference between the graft volume of experimental group 1 and experimental group 2 and the control group was statistically significant ( t=26.522 and t=37.183, all P<0.01), There was no significant difference in graft volume ( t=1.250, P>0.05). The wet weight of grafts in experimental group 1 was (0.200±0.021) g, that in experimental group 2 was (0.175±0.019) g, and that in the control group was (0.129±0.012) g, there was significant difference between experimental groups 1 and 2 and the control group ( t=11.601 and t=9.978, P<0.05), but there was no significant difference between experimental group 1 and experimental group 2 ( t=3.650, P>0.05). After oil red O staining, the grafts in experimental groups 1 and 2 were generally orange yellow, and the control group was scattered light yellow. The expression of CD31 in the experimental groups 1 and 2 was positive, and the expression of CD31 in control group was negative. Conclusions:Active ADSCs can be extracted from the granular fat layer and the lower filtrate of the static fat aspirate, and the ADSCs from both sources have good lipogenic ability in nude mice.

Role of active ADM microparticle in skin wound healing of diabetic mice / 中华医学美学美容杂志

Objective:To evaluate the effects of adipose-derived stem cells (ADSCs) and ADM microparticle on diabetic wound healing.Methods:ADSCs was co-cultured with ADM microparticle in vitro. The models of diabetic nude mice were established by intraperitoneal injection of STZ and the full-thickness skin defects were designed on the back. All 24 diabetic mice were randomly divided into 4 group: experimental groups were transplanted with ADSCs and ADM microparticle and the other groups were transplanted with ADSCs, ADM microparticle and blank control group was set up. On the 7th and 14 th days, the wound healing rate of 3 mice randomly selected from each group was calculated, and the thickness between dermis and epidermis was measured by hematoxylin and eosin staining. The density of neovascularization was measured by immunohistochemical staining. The differences were compared between the groups.Results:Compared to the ADSCs groups, the mice of the experimental groups showed higher cell survival rate. The wound healing rate in the experimental groups was (86.0±2.7)% (7 days) and (98.5±1.1)% (14 days), thicker dermis-epidermis distance was (99.1±1.8) μm (7 days) and (124.3±4.3) μm (14 days) ( P<0.05), and higher density of neovascularization was noted. Conclusions:The transplantation with active ADM microparticle can significantly promote neovascularization and wound healing of diabetic wound.

Stem cell therapy for alopecia areata / 中华皮肤科杂志

It is currently considered that alopecia areata is caused by the impairment of immune privilege in hair follicles. Stem cells have immunoregulatory functions, and can secrete a variety of cytokines to promote immune privilege in hair follicles. Stem cell therapy, especially umbilical cord- and adipose-derived stem cell therapy, has been applied to a variety of preclinical and clinical studies on alopecia, providing a new approach to refractory alopecia areata.

Effect of donor age on biological characteristics of adipose-derived stem cells / 中华医学美学美容杂志

Objective:To identify the influence of age factors on biological characteristics of human adipose-derived stem cells (ADSCs), and to compare the differences in morphology, aging characteristics, differentiation potential, surface marker expression, and proliferation ability of human ADSCs with different ages and the effect of human ADSCs of different ages on proliferation and migration of fibroblasts.Methods:Adipose tissues from 27 individuals of healthy beauty treatments, aged 0-59 years, were collected from Department of Burns and Plastic Surgery, the 940th Hospital of Joint Logistics Support Force from January 2020 to December 2020. According to the age of the donor, they were divided into 6 groups. 0-9 years old group (4 cases), 10-19 years old group (4 cases), 20-29 years old group (5 cases), 30- 39 years old group (5 cases), 40-49 years old group (5 cases), and 50-59 years old group (4 cases). We obtained and cultured the ADSCs of each group, subcultured to obtain the ADSCs, and observed the morphological characteristics of each group; the proliferation ability of each group of ADSCs was detected by CCK-8 method; the differentiation potential of each group of ADSCs was detected by in vitro adipogenesis and osteogenic induction. Flow cytometry was used to detect the surface marker expression levels of each group of ADSCs, and qPCR was used to detect the expression levels of HGF, PPAR-γ, type Ⅲ collagen and DbX2 in each group. We also collected the skin tissues of a healthy person from Department of Burns and Plastic Surgery of the 940th Hospital of Joint Logistics Support Force in 2020, obtained and cultured fibroblasts, subcultured to obtain the second generation of fibroblasts, and prepared each group of ADSCs conditioned medium (ADSCs-CM); the proliferation ability of fibroblasts cultured in each group of ADSCs-CM was detected by CCK-8 method, and the migration ability of fibroblasts cultured in each group of ADSCs-CM was detected by cell scratch method. SPSS 21.0 software was used for data analysis and P<0.05 was considered statistically significant. Results:The cells of all age groups were in a typical spindle shape. The cells of the younger age group showed small nuclei and the cell morphology were uniform and similar; the cells of the older age group had larger nuclei and uneven morphology. With aging, the proliferation ability of ADSCs gradually decreased. In vitro adipogenic differentiation induction results showed that with the increase in age, the ability of ADSCs to differentiate into adipocytes gradually decreased. In vitro osteogenic differentiation induction results also demonstrated that with the increase in age, the ability of ADSCs to differentiate into osteoblasts gradually decreased. The expression rates of positive surface markers of ADSCs in each group of ADSCs were all above 93%. With aging, the expression levels of PPAR-γ, HGF, and type Ⅲ collagen decreased, and the expression levels of DbX2 showed an upward trend with age. The number of β-galactosidase staining positive cells increased with age, while the difference between groups A, B and C was not statistically significant, and the difference between groups A and D, E, and F was statistically significant ( P<0.05). The ADSCs conditioned medium of each group was able to promote the proliferation of fibroblasts, but the difference between the groups was not statistically significant. With aging, the ability of ADSCs conditioned medium to promote the migration of fibroblasts gradually decreased. Conclusions:The proliferation ability and multidirectional differentiation ability of human ADSCs and the ability to secrete a variety of cytokines that promote the proliferation and migration of fibroblasts show a downward trend, but the adipogenic differentiation ability of ADSCs declines significantly after the age of 40 years. ADSCs in all age groups could promote the proliferation and migration of fibroblasts.

The role of LncRNA00602 in Ad36-induced differentiation of adipocytes / 中华内分泌代谢杂志

Objective:To investigate the possible role of long non-coding RNA (LncRNA) 00602 in promoting browning in adipocytes induced by adenovirus type 36 (Ad36).Methods:According to Ad36 infection, adipose tissue samples of obese patients were divided into Ad36-negative group and Ad36-infected group. Realtime fluorescent quantitative PCR (qRT-PCR) was used to detect the changes in the expression of LncRNA00602 mRNA in omental adipose tissue of the two groups, and analyze the differences between the two groups. The correlation between waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triacylglyceride and other indicators of the patients in the group with LncRNA00602 mRNA expression were analyzed. HE staining was used to detect the size of adipocytes in the omental adipose tissue of the Ad36 negative group and the Ad36 infection group. qRT-PCR and Western blotting were used to detect the mRNA and protein expression levels of uncoupling protein 1 (UCP1) and PR domain containing 16 (PRDM16) in omental adipose tissue of two groups of patients. Human adipose-derived stem cells (hADSC) were isolated and cultured, using Ad36 to induce differentiation, and divided into control group and LncRNA00602 knockdown group. On 0, 2, and 4 days after LncRNA00602 knockdown, fluoroboron dipyrrole (BODIPY) and mitochondrial red fluorescence (Mito-Tracker Red) were used to stain intracellular lipid droplets and mitochondria. At the same time, qRT-PCR and Western blotting were used to detect changes in the expression of UCP1 and PRDM16.Results:The expression of LncRNA00602 gene in the Ad36 infection group was higher than that in the Ad36 negative group (all P<0.05). The expression of LncRNA00602 in the Ad36 negative group was not significantly different from the above clinical indicators, while the expression of LncRNA00602 was negatively correlated with serum fasting blood glucose and triacylglyceride ( r=-0.522, -0.486, P<0.05) in the Ad36 infection group; HE staining showed that the average adipocyte area of the Ad36 infection group was smaller than that of the Ad36 negative group. At the same time, UCP1 and PRDM16 gene expression were higher than the negative group (all P<0.05). At the cellular level, on the 2nd and 4th days after knockdown of LncRNA00602, the lipid droplet area of adipocytes in the LncRNA00602 knockdown group was larger than that of the control group, the number of mitochondria decreased compared with the control group, and difference was statistically significant ( P<0.05 or P<0.01); Compared with the control group, there was significantly lower expression of the browning marker genes UCP1, PRDM16, and protein in the adipocytes in the LncRNA00602 knockdown group (all P<0.05). Conclusion:In Ad36-induced adipocyte differentiation, LncRNA00602 may positively regulate the expression of UCP1, PRDM16 and lipid droplet metabolism, and promote the browning of adipocytes.

Extracellular vesicle activities regulating macrophage- and tissue-mediated injury and repair responses

Macrophages are typically identified as classically activated (M1) macrophages and alternatively activated (M2) macrophages, which respectively exhibit pro- and anti-inflammatory phenotypes, and the balance between these two subtypes plays a critical role in the regulation of tissue inflammation, injury, and repair processes. Recent studies indicate that tissue cells and macrophages interact

Research progress of hydrogel combined with mesenchymal stem cells in the treatment of spinal cord injury / 生物医学工程学杂志

Spinal cord injury (SCI) is a complex pathological process. Based on the encouraging results of preclinical experiments, some stem cell therapies have been translated into clinical practice. Mesenchymal stem cells (MSCs) have become one of the most important seed cells in the treatment of SCI due to their abundant sources, strong proliferation ability and low immunogenicity. However, the survival rate of MSCs transplanted to spinal cord injury is rather low, which hinders its further clinical application. In recent years, hydrogel materials have been widely used in tissue engineering because of their good biocompatibility and biodegradability. The treatment strategy of hydrogel combined with MSCs has made some progress in SCI repair. This review discusses the significance and the existing problems of MSCs in the repair of SCI. It also describes the research progress of hydrogel combined with MSCs in repairing SCI, and prospects its application in clinical research, aiming at providing reference and new ideas for future SCI treatment.

Estudo da morfologia e status oxidativo em rim de ratos com nefropatia isquêmica após tratamento com células-tronco mesenquimais de tecido adiposo / Study of morphology and oxidative status in kidney of rats with ischemic nephropathy after treatment with adipose tissue mesenchymal stem cells

A nefropatia isquêmica é uma doença renal crônica provocada pela redução do fluxo sanguíneo renal que pode progredir para a doença renal terminal, cujo tratamentos disponíveis se baseiam em terapias substitutivas da função renal, como diálise ou transplante renal. No entanto, devido ao alto custo dos tratamentos e a carência de órgãos, se faz necessária a busca por novas terapias, como as células-tronco (CT). Apesar do potencial terapêutico das CT em doenças crônicas, não está claro se essas células mantêm seus efeitos benéficos em órgãos lesionados por tempo prolongado. O objetivo desse estudo foi avaliar os efeitos precoces e tardios do tratamento com células-tronco adiposas (CTA) sobre a morfologia e o status oxidativo em rins de ratos com nefropatia isquêmica. A isquemia renal foi induzida pelo modelo 2rins-1clip (2R1C) e, depois de um mês da clipagem da artéria renal, foram injetadas 106 células-tronco na região subscapsular do rim afetado. Após 15 e 30 dias da injeção das CTA, a morfologia renal foi verificada por meio da análise macroscópica, microscópica e ultraestrutural. Além disso, o status oxidativo foi avaliado no tecido renal através da mensuração da atividade das enzimas antioxidantes catalase e glutationa peroxidase; e de marcadores biológicos de dano oxidativo, como proteínas carboniladas, 3-Nitrotirosina e 4-Hidroxinonenal. Por imunoperoxidase foi possível localizar as células-tronco adiposas GFP+ foram rastreadas e encontradas tanto 15 dias, quanto 30 dias após a injeção na região subcapsular. A restauração da arquitetura renal foi evidenciada 15d após o uso das células, onde detectamos redução na deposição de fibras colágenas no parênquima renal, o que não foi observado 30d após o uso das células. Os resultados também foram confirmados através da análise da ultraestrutura renal que mostraram restauração da arquitetura renal no grupo de 15d, não evidenciada no grupo de 30d. Quanto a análise do status oxidativo, somente os animais com nefropatia isquêmica mais prolongada apresentaram estresse oxidativo com redução da atividade da enzima antioxidante catalase no tecido renal. Além disso, foi observado dano proteico e lipídico, sem melhora dessa condição nos animais 30d após o tratamento com as células-tronco. No modelo de nefropatia isquêmica avaliado, o tratamento com CTA mostrou benefícios na morfologia renal a curto prazo, mas não tardiamente, apesar da permanência dessas células no tecido. Acreditamos que o estresse oxidativo, evidenciado somente no tecido renal com isquemia mais prolongada, possa ter dificultado a ação das células-tronco, contribuindo para tais achados. Esses resultados abrem perspectivas para o aprofundamento do estudo quanto à caracterização dos mecanimos de ação das CTA nas respostas anti-fibrogênicas, assim como o estabelecimento do número, frequência, vias de administração e melhor momento para uso dessas células no tratamento de doenças renais crônicas.

Ischemic nephropathy is a chronic kidney disease caused by reduced kidney blood flow that can progress to end stage kidney disease, whose available treatments are based on kidney function replacement therapies, such as dialysis or kidney transplantation. However, due to the high cost of treatments and the lack of organs, it is necessary to search for new therapies, such as stem cells (SC). Despite the therapeutic potential of SC in chronic diseases, it is unclear whether these cells maintain their beneficial effects on injured organs for a long time. The aim of this study was to evaluate the early and late effects of adipose-derived stem cells (ADSC) treatment on the morphology and oxidative status in kidneys of rats with ischemic nephropathy. Renal ischemia was induced by the 2kidneys-1clip (2K1C) model and, after a month of clipping the renal artery, 106 stem cells were injected into the subscapsular region of the affected kidney. After 15 and 30 days of ADSC injection, renal morphology was verified by macroscopic, microscopic, and ultrastructural analysis. In addition, oxidative status was assessed in renal tissue by measuring the activity of the antioxidant enzymes catalase and glutathione peroxidase; and biological markers of oxidative damage, such as carbonylated proteins, 3-nitrotyrosine and 4-hydroxynonenal. By immunoperoxidase, it was possible to locate GFP + adipose-derived stem cells that were tracked and found both 15 days and 30 days after injection in the subcapsular region. The restoration of the renal architecture was evidenced 15d after the use of the cells, where we detected a reduction in the deposition of collagen fibers in the renal parenchyma, which was not observed 30d after the use of the cells. The results were also confirmed by analyzing the renal ultrastructure, which showed restoration of the renal architecture in the 15d group, not evidenced in the 30d group. Regarding the analysis of oxidative status, only animals with more prolonged ischemic nephropathy presented oxidative stress with reduced activity of the antioxidant enzyme catalase in renal tissue. In addition, protein and lipid damage was observed, with no improvement in this condition in the animals 30d after treatment with stem cells. In the evaluated ischemic nephropathy model, treatment with ADSC showed benefits in renal morphology in the short term, but not late, despite the permanence of these cells in the tissue. We believe that oxidative stress, evidenced only in renal tissue with more prolonged ischemia, may have hindered the action of stem cells, contributing to such findings. These results open perspectives for further study on the characterization of ADSC mechanisms of action in anti-fibrogenic responses, as well as the establishment of the number, frequency, routes of administration and the best time to use these cells in the treatment of chronic kidney diseases.

Roles of adipocytes and adipose-derived stem cells in the lipophilic metastasis of ovarian cancer / 中国肿瘤临床

Ovarian cancer is the most common cause of cancer-associated deaths among the gynecological malignancies. The 5-year survival rate of the patients is less than 30%. This high mortality rate is mainly due to the metastasis. Adipose-rich omentum is the main site of metastasis, suggesting that ovarian cancer may have the characteristic of "lipophilic" metastasis. Adipocytes and adipose-derived stem cells are the most important components of the omentum. These cell ssecrete cytokines and adipokines and modify glucose and lipid metabolism to induce migration of ovarian cancer cells to the omentum. Simultaneously, they create a suitable microenvironment for the metastasis and colonization of these cancer cells by interacting with vascular endothelial cells, tumor-associated macrophages, and cancer-associated fibroblasts. This article reviews the recent advances in the role of adipocytes and adipose-derived stem cells in the "lipophilic" metastasis of ovarian cancer, aiming at providing new ideas for preventing ovarian cancer metastases and improving the survival rate of patients with ovarian cancer.

Ammonium chloride lysis method versusnon-lysis method for isolation of human adipose-derived stem cells / 中国组织工程研究

BACKGROUND: A general standard has not been established for the extraction and purification of adipose-derived stem cells (ADSCs). An erythrocyte lysis step for stromal vascular fraction is the commonly used method in the procedure for ADSCs isolation. However, there is a lack of evidence on whether this step will have adverse effects on human ADSCs (hADSCs). OBJECTIVE: To test the efficiency of two hADSCs isolation methods, which are erythrocyte-lysis method based on ammonium chloride and non-lysis method. Moreover, the biological characteristics of the hADSCs isolated by the two methods were also compared. METHODS: After collagenase digestion of lipoaspirate, erythrocyte lysis buffer was used to purify stromal vascular fraction in erythrocyte-lysis method, while in non-lysis method the buffer was not used. A Muse™ cell analyzer was used to assess living cell counting and proportion of stromal vascular fraction in both methods. Then hADSCs were cultured to the second passage for next testing. Cell morphology was observed under light microscope. Cell phenotype was detected by flow cytometry. Cell counting kit-8 was used to evaluate cell proliferation. Oil red O staining and alizarin staining were used to evaluate adipogenic and osteogenic ability of hADSCs after adipogenic and osteogenic induction. This study was approved by the Ethics Committee of the Plastic Surgery Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, and informed consents were signed by all participants. RESULTS AND CONCLUSION: (1) Compared with the erythrocyte lysis group, hADSCs obtained in the non-lysis group contained a larger number and a larger percentage of non-erythrocyte living cells. (2) The two groups of hADSCs were spindle-shaped and arranged as a fish shape. (3) The cell phenotypes of both groups met the phenotypic requirements for human mesenchymal stem cells. (4) The cell proliferation in the non-lysis group was faster than that in the erythrocyte lysis group, while there was no difference in the adipogenic and osteogenic abilities between the two groups. In conclusion, the use of erythrocyte lysis buffer reduces the isolation efficiency of hADSCs and inhibits cell proliferation. The non-lysis isolation method does not affect phenotypes, adipogenic and osteogenic ability of hADSCs. Therefore, it is not recommended to implement erythrocyte lysis during the isolation of hADSCs.

Research progress in osteogenic differentiation of adipose-derived stem cells induced by bioscaffold materials / 中国组织工程研究

BACKGROUND: Adipose-derived stem cells are easy to access and have strong proliferative capacity, which are considered as ideal seed cells for bone defect repair. The bone tissue engineering research progress reveals that bioscaffold material modification can directly regulate the osteogenic differentiation of stem cells. OBJECTIVE: To review various biological scaffold materials that can regulate the osteogenic differentiation of adipose-derived stem cells. METHODS: The first author searched the articles in CNKI, WanFang, VIP, PubMed, Embase and Web of Science databases published from January 2016 to May 2019. The search terms were “adipose derived stem cells, scaffold, osteogenic, metal, Ti” in Chinese and English, respectively. Finally 62 eligible articles were selected. RESULTS AND CONCLUSION: Scaffold materials for bone tissue engineering are classified into inorganic materials (hydroxyapatite, tricalcium phosphate, bioglass, titanium, and magnesium), natural polymer materials (collagen, silk fibroin, and chitosan) and synthetic polymer materials (polycaprolactone, polylactic acid, polyglycolic acid and poly(lactic-co-glycolic acid)). The studies on materials that interact with cells to guide their biological response and bone differentiation are increasing. But how to create a safe, rational, and close to the micro-environment of cell growth in vivo is a challenge. Modification of bioscaffold materials can directly regulate osteogenic differentiation of stem cells. Moreover, vascularization and post-implantation infections are issues of concern.

Role and potential of adipose-derived stem cells in cranio-maxillofacial bone regeneration / 中国组织工程研究

BACKGROUND: The repair of cranio-maxillofacial bone defects is still facing severe challenges, and the introduction of the concept of bone regeneration points out a new direction for this problem. Adipose-derived stem cells are easy to access and have strong osteogenic differentiation capacity, which are considered as ideal seed cells for cranio-maxillofacial bone regeneration. OBJECTIVE: To review the influencing factors of osteogenic differentiation of adipose-derived stem cells as well as the research progress in cranio-maxillofacial bone regeneration, thus providing ideas for further study on adipose-derived stem cells in promoting cranio-maxillofacial bone regeneration. METHODS: A computer-based online search of PubMed, Wanfang, and CNKI databases was performed to retrieve papers published from January 2013 to February 2020 with the search terms of “adipose-derived stem cells, cranio-maxillofacial, oral tissue regeneration, periodontal tissue regeneration, bone regeneration, bone defects, osteogenesis” in English and Chinese. Finally, 88 papers were included for summary. RESULTS AND CONCLUSION: Adipose-derived stem cells can be induced to differentiate to osteoblasts and are easy to acquire in large quantities. It has a strong ability of expansion in vitro and has a broad application prospect in the field of cranio-maxillofacial bone regeneration. miRNAs/microRNAs play a role in the osteogenic differentiation of adipose-derived stem cells. The osteogenic differentiation ability of adipose-derived stem cells can be improved by the means of co-culture with other cells, combined with platelet-rich plasma or modified titanium and gene technology. Compared with conventional extracorporeal scaffolds, adipose-derived stem cells combined with injectable scaffolds have greater potential in osteogenesis. Some progress has been made in repairing cranio-maxillofacial bone defects with adipose-derived stem cells, but there is still a lack of sufficient evidence in large-scale clinical trials.

Proteomics analysis of exosomes from adipose-derived stem cells in skin damage repair / 中国组织工程研究

BACKGROUND: There are lots of researches about using adipose-derived stem cells to promote damage repair, but the studies from the perspective of exosome from adipose-derived stem cells based on proteomics and bioinformatics technologies are rarely reported. OBJECTIVE: To analyze the differentially expressed proteins of exosome from adipose-derived stem cells between diabetic patients with leg ulcers and healthy adults through proteomics and bioinformatics technologies, so as to screen out the diagnostic and prognostic landmarks. METHODS: Adipose-derived stem cells were obtained from 25 diabetic patients (trial group) with leg ulcers who accepted debridement skin grafting at the Department of Plastic and Burn, Second Affiliated Hospital of Air Force Military Medical University from October 2018 to May 2019 and 10 healthy adults who concurrently accepted liposuction (control group). Exosomes from adipose-derived stem cells were extracted for identification. Three cases were randomly selected from each group for proteomics analysis. LFQ technology was used to conduct quantitative analysis. GO and Pathway analysis for the differentially expressed proteins were performed using clueGO (version 2.5.4) was used to do. The transactional analysis between proteins was conducted (String database, version 11.0, R software clusterProfi ler package, FDR < 0.25). RESULTS AND CONCLUSION: (1) Totally 231 quantitative differentially expressed proteins were screened out, 31 kinds of which had significant difference. There were 29 down-regulated proteins and 2 up-regulated proteins in the trial group. (2) Differential proteins had a high correlation with nutrition and metabolic diseases. Differentially expressed proteins were mostly expressed in extracellular vesicles and platelet alpha granules and were mainly involved in two biological processes-coagulation process and lipid transport. The main molecular functions of differential proteins were related to enzyme inhibitor activity and heparin binding capacity. (3) The pathway analysis of PPI and KEGG showed that the significantly down-regulated ITGA2B and ITGB3 proteins were closely related to the course of the disease in the trial group, both of which are expected to be the new targets in stem cell treatment for diabetes with leg ulcers.

Addition Of Adipose Derived Stem Cell To Beta Tricalcium Phosphate and Human Cancellous Bone for Craniofacial Bone Tissue Engineering: An In Vitro Study

@#Introduction: Autologous bone graft remains the method of choice for correction of osseous defects despite its shortcomings related to its limited availability, donor side effects and post-surgical potential complications of the recipient. It is imperative to develop more innovative substitute that offers little to no adverse effects. We aimed to assess the impact of addition human adiposed derived stem cell to Beta tricalcium phosphate (βTCP) and human cancellous bone in vitro. Methods: Experimental study was carried out in vitro, where βTCP and human cancellous freeze-dried bone graft were seeded onto a 24-well microplate (each well containing 2x106 hADSCs). A colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide/MTT) was carried out for three days using the second passage of hADSCs to calculate the cell viability using ELISA reader at optical density (OD) 590nm. Results: MTT Assay showed that the percentage of viable cells in both groups were more than 70%, of which the βTCP showed significantly higher percentage than cancellous bone groups. Conclusion: This study proved that the addition of human adipose derived stem cell to βTCP and human cancellous bone in vitro is harmless and significantly improve cell viability in vitro.

Effects of adipose-derived stem cell released exosomes on wound healing in diabetic mice / 中国修复重建外科杂志

Objective: To investigate the effects of adipose-derived stem cell released exosomes (ADSC-Exos) on wound healing in diabetic mice. Methods: The ADSCs were isolated from the adipose tissue donated by the patients and cultured by enzymatic digestion. The supernatant of the 3rd generation ADSCs was used to extract Exos (ADSC-Exos). The morphology of ADSC-Exos was observed by transmission electron microscopy. The membrane-labeled proteins (Alix and CD63) were detected by Western blot, and the particle size distribution was detected by nanoparticle tracking analyzer. The fibroblasts were isolated from the skin tissue donated by the patients and cultured by enzymatic digestion. The 5th generation fibroblasts were cultured with PKH26-labeled ADSC-Exos, and observed by confocal fluorescence microscopy. The effects of ADSC-Exos on proliferation and migration of fibroblasts were observed with cell counting kit 8 (CCK-8) and scratch method. Twenty-four 8-week-old Balb/c male mice were used to prepare a diabetic model. A full-thickness skin defect of 8 mm in diameter was prepared on the back. And 0.2 mL of ADSC-Exos and PBS were injected into the dermis of the experimental group ( n=12) and the control group ( n=12), respectively. On the 1st, 4th, 7th, 11th, 16th, and 21st days, the wound healing was observed and the wound healing rate was calculated. On the 7th, 14th, and 21st days, the histology (HE and Masson) and CD31 immunohistochemical staining were performed to observe the wound structure, collagen fibers, and neovascularization. Results: ADSC-Exos were the membranous vesicles with clear edges and uniform size; the particle size was 40-200 nm with an average of 102.1 nm; the membrane-labeled proteins (Alix and CD63) were positive. The composite culture observation showed that ADSC-Exos could enter the fibroblasts and promote the proliferation and migration of fibroblasts. Animal experiments showed that the wound healing of the experimental group was significantly faster than that of the control group, and the wound healing rate was significantly different at each time point ( P<0.05). Compared with the control group, the wound healing of the experimental group was better. There were more microvessels in the early healing stage, and more deposited collagen fibers in the late healing stage. There were significant differences in the length of wound on the 7th, 14th, and 21st days, the number of microvessels on the 7th and 14th days, and the rate of deposited collagen fibers on the 14th and 21st days between the two groups ( P<0.05). Conclusion: ADSC-Exos can promote the wound healing in diabetic mice by promoting angiogenesis and proliferation and migration of fibroblasts and collagen synthesis.

Construction of tissue engineered adipose by human adipose tissue derived extracellular vesicle combined with decellularized adipose tissues scaffold / 中国修复重建外科杂志

Objective: To explore the possibility of constructing tissue engineered adipose by adipose tissue derived extracellular vesicles (hAT-EV) combined with decellularized adipose tissue (DAT) scaffolds, and to provide a new therapy for soft tissue defects. Methods: The adipose tissue voluntarily donated by the liposuction patient was divided into two parts, one of them was decellularized and observed by HE and Masson staining and scanning electron microscope (SEM). Immunohistochemical staining and Western blot detection for collagen type Ⅰ and Ⅳ and laminin were also employed. Another one was incubated with exosome-removed complete medium for 48 hours, then centrifuged to collect the medium and to obtain hAT-EV via ultracentrifugation. The morphology of hAT-EV was observed by transmission electron microscopy; the nanoparticle tracking analyzer (NanoSight) was used to analyze the size distribution; Western blot was used to analyse membrane surface protein of hAT-EV. Adipose derived stem cells (ADSCs) were co-cultured with PKH26 fluorescently labeled hAT-EV, confocal fluorescence microscopy was used to observe the uptake of hAT-EV by ADSCs. Oil red O staining was used to evaluate adipogenic differentiation after hAT-EV and ADSCs co-cultured for 15 days. The DAT was scissored and then injected into the bilateral backs of 8 C57 mice (6-week-old). In experimental group, 0.2 mL hAT-EV was injected weekly, and 0.2 mL PBS was injected weekly in control group. After 12 weeks, the mice were sacrificed, and the new fat organisms on both sides were weighed. The amount of new fat was evaluated by HE and peri-lipoprotein immunofluorescence staining to evaluate the ability of hAT-EV to induce adipogenesis in vivo. Results: After acellularization of adipose tissue, HE and Masson staining showed that DAT was mainly composed of loosely arranged collagen with no nucleus; SEM showed that no cells and cell fragments were found in DAT, and thick fibrous collagen bundles could be seen; immunohistochemical staining and Western blot detection showed that collagen type Ⅰ and Ⅳ and laminin were retained in DAT. It was found that hAT-EV exhibited a spherical shape of double-layer envelope, with high expressions of CD63, apoptosis-inducible factor 6 interacting protein antibody, tumor susceptibility gene 101, and the particle size of 97.9% hAT-EV ranged from 32.67 nmto 220.20 nm with a peak at 91.28 nm. Confocal fluorescence microscopy and oil red O staining showed that hAT-EV was absorbed by ADSCs and induced adipogenic differentiation. In vivo experiments showed that the wet weight of fat new organisms in the experimental group was significantly higher than that in the control group ( t=2.278, P=0.048). HE staining showed that the structure of lipid droplets in the experimental group was more than that in the control group, and the collagen content in the control group was higher than that in the experimental group. The proportion of new fat in the experimental group was significantly higher than that in the control group ( t=4.648, P=0.017). Conclusion: DAT carrying hAT-EV can be used as a new method to induce adipose tissue regeneration and has a potential application prospect in the repair of soft tissue defects.

Research progress of adipose-derived stem cells in promoting the repair of peripheral nerve injury / 中国修复重建外科杂志

Objective: To summarize the research progress of adipose-derived stem cells (ADSCs) in promoting the repair of peripheral nerve injury. Methods: The related literature at home and abroad in recent years was widely reviewed, the mechanism of ADSCs promoting the repair of peripheral nerve injury was introduced, and its basic research progress was analyzed and summarized. Finally, the clinical transformation application of ADSCs in the treatment of peripheral nerve injury was introduced, the existing problems were pointed out, and the new treatment regimen was prospected. Results: ADSCs have the function of differentiation and paracrine, and their secreted neurotrophic factors, antiapoptosis, and antioxidant factors can promote the repair of peripheral nerve injury. Conclusion: ADSCs are rich in content and easy to obtain, which has a definite effectiveness on the repair of peripheral nerve injury with potential clinical prospect.

In vitro study on promoting migration ability of rat adipose derived stem cells modified by stromal cell-derived factor 1α / 中国修复重建外科杂志

Objective: To explored the effect of stromal cell-derived factor 1α (SDF-1α) on promoting the migration ability of rat adipose derived stem cells (rADSCs) by constructed the rADSCs overexpression SDF-1α via adenovirus transfection. Methods: rADSCs were isolated from adipose tissue of 6-week-old SPF Sprague Dawley rats. Morphological observation, multi-directional differentiations (osteogenic, adipogenic, and chondrogenic inductions), and flow cytometry identification were performed. Transwell cell migration experiment was used to observe and screen the optimal concentration of exogenous SDF-1α to optimize the migration ability of rADSCs; the optimal multiplicity of infection (MOI) of rADSCs was screened by observing the cell status and fluorescence expression after transfection. Then the third generation of rADSCs were divided into 4 groups: group A was pure rADSCs; group B was rADSCs co-cultured with SDF-1α at the best concentration; group C was rADSCs infected with recombinant adenovirus-mediated green fluorescent protein (Adv-GFP) with the best MOI; group D was rADSCs infected with Adv-GFP-SDF-1α overexpression adenovirus with the best MOI. Cell counting kit 8 (CCK-8) and Transwell cell migration experiment were preformed to detect and compare the effect of exogenous SDF-1α and SDF-1α overexpression on the proliferation and migration ability of rADSCs. Results: The cell morphology, multi-directional differentiations, and flow cytometry identification showed that the cultured cells were rADSCs. After screening, the optimal stimulating concentration of exogenous SDF-1α was 12.5 nmol/L; the optimal MOI of Adv-GFP adenovirus was 200; the optimal MOI of Adv-GFP-SDF-1α overexpression adenovirus was 400. CCK-8 method and Transwell cell migration experiment showed that compared with groups A and C, groups B and D could significantly improve the proliferation and migration of rADSCs ( P<0.05); the effect of group D on enhancing the migration of rADSCs was weaker than that of group B, but the effect of promoting the proliferation of rADSCs was stronger than that of group D ( P<0.05). Conclusion: SDF-1α overexpression modification on rADSCs can significantly promote the proliferation and migration ability, which may be a potential method to optimize the application of ADSCs in tissue regeneration and wound repair.