Proliferation Of Adipose-derived Stem Cells Research Articles

Expression profiles of exosomal tRNA-derived fragments and their biological functions in lipomas.

There is evidence that exosomes derived from the lipoma tissue (Exo-LT) have a stronger capacity to promote the proliferation and migration of adipose-derived stem cells (ADSCs) than those from the adipose tissue (Exo-AT). But the Exo-LT do not have a significant effect on the adipogenic differentiation of the ADSCs. Recently, certain exosomal tRNA-derived fragments (tRFs) have been shown to play a crucial role in the pathogenesis of certain tumors. Therefore, it is necessary to identify the differently expressed tRFs in Exo-LT to further elucidate their molecular functions in lipomas. High-throughput sequencing was performed to examine the tRFs and mRNAs from the all samples belonging to the Exo-LT and Exo-AT groups. Target prediction and bioinformatics analysis were performed to explore their downstream mRNAs and biological functions. In total, 456 differently expressed tRFs and tiRNAs were identified in the Exo-LT group, 12 of which were up-regulated and 12 were down-regulated, respectively. Notably, tRF-1001 was most obviously down-regulated and tRF-3004a was most obviously up-regulated in the Exo-LT group. Moreover, among the target genes of tRF-1001 and tRF-3004a, both JAG2 and VSIG4 were significantly down-regulated in the Exo-LT group, while WNT5A, COL1A1, and PPARGC1A were highly expressed in both the Exo-LT and Exo-AT groups. The significant down-regulation of JAG2 and VSIG4 in the Exo-LT group could be due to the fact that Exo-LT had a stronger capacity to promote the proliferation and migration of ADSCs compared to the Exo-AT. The high expression of WNT5A, COL1A1, and PPARGC1A in both the Exo-LT and Exo-AT groups could be due to the similar ability of Exo-LT and Exo-AT to promote the adipogenic differentiation of ADSCs.

Melatonin enhances autologous adipose-derived stem cells to improve mouse ovarian function in relation to the SIRT6/NF-κB pathway

BackgroundPremature ovarian insufficiency (POI) is the main cause of female infertility. Adipose-derived stem cells (ADSCs) are ideal candidates for the treatment of POI. However, some deficient biological characteristics of ADSCs limit their utility. This study investigated whether melatonin (MLT)-pretreated autologous ADSCs were superior to ADSCs alone in the treatment of the POI mouse model.MethodsAutologous ADSCs were isolated and cultured in MLT-containing medium. Surface markers of ADSCs were detected by flow cytometry. To determine the effect of MLT on ADSCs, CCK-8 assay was used to detect ADSCs proliferation and enzyme-linked immunosorbent assay (ELISA) was used to detect the secretion of cytokines. The POI model was established by intraperitoneal injection of cyclophosphamide and busulfan. Then, MLT-pretreated autologous ADSCs were transplanted into mice by intraovarian injection. After 7 days of treatment, ovarian morphology, follicle counts, and sex hormones levels were evaluated by hematoxylin and eosin (H&E) staining and ELISA, and the recovery of fertility was also observed. The expressions of SIRT6 and NF-κB were detected by immunohistochemical (IHC) staining and quantitative real-time polymerase chain reaction (qRT-PCR).ResultsFlow cytometry showed that autologous ADSCs expressed CD90 (99.7%) and CD29 (97.5%). MLT can not only promote the proliferation of ADSCs but also boost their secretory function, especially when ADSCs were pretreated with 5 µM MLT for 3 days, improving the interference effect. After transplantation of autologous ADSCs pretreated with 5 µM MLT, the serum hormone levels and reproductive function were significantly recovered, and the mean counts of primordial follicle increased. At the same time, the expression of SIRT6 was remarkably increased and the expression of NF-κB was significantly decreased in this group.ConclusionsMLT enhances several effects of ADSCs in restoring hormone levels, mean primordial follicle counts, and reproductive capacity in POI mice. Meanwhile, our results suggest that the SIRT6/NF-κB signal pathway may be the potential therapeutic mechanism for ADSCs to treat POI.

Covalent and biodegradable chitosan-cellulose hydrogel dressing containing microspheres for drug delivery and wound healing

The purpose of this study is to prepare polysaccharide-based hydrogel dressing integrated with microspheres which has excellent self-healing ability and sustained antibacterial function for wound healing application. The hydrogel is derived from carboxymethyl chitosan (CMCS) and carboxymethyl cellulose (CMC) via the Schiff’s base reaction, without the addition of chemical catalyst. Also, the CMCS microspheres containing an antibacterial drug, e.g., tetracycline hydrochloride (TH), were prepared by an emulsion cross-linking. Parameters were optimized during the preparation experiment to improve various properties of the microspheres/hydrogel composite dressing. This gel dressing has good elasticity, when compressive strain was 0.7 mm/mm, the tangent elastic modulus was up to 1.7 MPa. Furthermore, its drug sustained release performance was significantly better than the drug directly embedded in the hydrogel. TH could sustain release stably within 12 h, without obvious burst release phenomenon. Antibacterial experiments showed that 20 mg/mL microspheres made composite dressing a better performance than control microspheres and hydrogel. Potential of the composite scaffolds was further demonstrated by culture of human adipose-derived stem cells (ASCs) in vitro. Cell culture showed that this composite hydrogel could support survival and proliferation of ASCs. These characteristics provide a potential opportunity to use this composite gel dressing in drug delivery and wound healing applications.

Low-Intensity Pulsed Ultrasound Enhanced Adipose-Derived Stem Cell-Mediated Angiogenesis in the Treatment of Diabetic Erectile Dysfunction through the Piezo-ERK-VEGF Axis.

Objectives Erectile dysfunction is a major comorbidity of diabetes. Stem cell transplantation is a promising method to treat diabetic erectile dysfunction. In this study, we evaluated whether low-intensity pulsed ultrasound (LIPUS) could enhance the efficacy of adipose-derived stem cells (ADSCs) and investigated the underlying molecular mechanism. Materials and methods. Sixty 8-week-old male Sprague–Dawley rats were randomly divided into the normal control (NC) cohort or the streptozocin-induced diabetic ED cohort, which was further subdivided into DM, ADSC, LIPUS, and ADSC+LIPUS groups. Rats in the ADSC or ADSC+LIPUS group received ADSC intracavernosal injection. Rats in the LIPUS or ADSC+LIPUS group were treated with LIPUS. The intracavernous pressure (ICP) and mean arterial pressure (MAP) were recorded at Day 28 after injection. The corpus cavernosum tissues were harvested and subjected to histologic analysis and ELISA. The effects of LIPUS on proliferation and cytokine secretion capacity of ADSCs were assessed in vitro. RNA sequencing and bioinformatic analysis were applied to predict the mechanism involved, and western blotting and ELISA were used for verification. Results Rats in the ADSC+LIPUS group achieved significantly higher ICP and ICP/MAP ratios than those in the DM, ADSC, and LIPUS groups. In addition, the amount of cavernous endothelium and cGMP level also increased significantly in the ADSC+LIPUS group. In vitro experiments demonstrated that LIPUS promoted proliferation and cell cycle progression in ADSCs. The excretion of cytokines such as CXCL12, FGF2, and VEGF was also enhanced by LIPUS. Bioinformatic analysis based on RNA sequencing indicated that LIPUS stimulation might activate the MAPK pathway. We confirmed that LIPUS enhanced ADSC VEGF secretion through the Piezo-ERK pathway. Conclusion LIPUS enhanced the curative effects of ADSCs on diabetic erectile dysfunction through the activation of the Piezo-ERK-VEGF pathway. ADSC transplantation combined with LIPUS could be applied as a synergistic treatment for diabetic ED.

A Three-Dimensional Printed Polycaprolactone-Biphasic-Calcium-Phosphate Scaffold Combined with Adipose-Derived Stem Cells Cultured in Xenogeneic Serum-Free Media for the Treatment of Bone Defects.

The efficacy of a three-dimensional printed polycaprolactone–biphasic-calcium-phosphate scaffold (PCL–BCP TDP scaffold) seeded with adipose-derived stem cells (ADSCs), which were cultured in xenogeneic serum-free media (XSFM) to enhance bone formation, was assessed in vitro and in animal models. The ADSCs were isolated from the buccal fat tissue of six patients using enzymatic digestion and the plastic adherence method. The proliferation and osteogenic differentiation of the cells cultured in XSFM when seeded on the scaffolds were assessed and compared with those of cells cultured in a medium containing fetal bovine serum (FBS). The cell–scaffold constructs were cultured in XSFM and were implanted into calvarial defects in thirty-six Wistar rats to assess new bone regeneration. The proliferation and osteogenic differentiation of the cells in the XSFM medium were notably better than that of the cells in the FBS medium. However, the efficacy of the constructs in enhancing new bone formation in the calvarial defects of rats was not statistically different to that achieved using the scaffolds alone. In conclusion, the PCL–BCP TDP scaffolds were biocompatible and suitable for use as an osteoconductive framework. The XSFM medium could support the proliferation and differentiation of ADSCs in vitro. However, the cell–scaffold constructs had no benefit in the enhancement of new bone formation in animal models.

S100A8 accelerates wound healing by promoting adipose stem cell proliferation and suppressing inflammation.

Adipose-derived stem cells (ADSCs) are stem cells with multidirectional differentiation potential isolated from adipose tissue. They have the same immunomodulatory effect as bone marrow mesenchymal stem cells in wound repair and immune regulation as bone marrow. The mechanism of action of ADSCs in skin wound repair has not been elucidated. S100A8 is a calcium and zinc binding protein, but its role in skin wound healing is rarely reported. We herein show that S100A8 overexpression significantly promoted ADSC proliferation and differentiation, whereas S100A8 knockdown yielded the opposite results. A skin injury model with bone exposure was created in rats by surgically removing the skin from the head and exposing the skull. The wounds were treated with S100A8-overexpressing or S100A8-knockdown ADSCs, and wound healing was monitored. The serum levels of the inflammation-related factors tumor necrosis factor-α and interleukin-6 were decreased significantly after S100A8 overexpression, while the angiogenic factor vascular endothelial growth factor and connective tissue generating factor showed the opposite trend. Histological staining revealed that granulation tissue neovascularization was more pronounced in wounds treated with S100A8-overexpressing ADSCs than that in the control group. We conclude that S100A8 promotes the proliferation of ADSCs and inhibits inflammation to improve skin wound healing.

High-Throughput Production of Microsponges from Platelet Lysate for Tissue Engineering Applications.

Cell-based therapies require a large number of cells, as well as appropriate methods to deliver the cells to damaged tissue. Microcarriers provide an optimal platform for large-scale cell culture while also improving cell retention during cell delivery. However, this technology still presents significant challenges due to low-throughput fabrication methods and an inability of the microcarriers to recreate the properties of human tissue. This work proposes, for the first time, the use of methacryloyl platelet lysates (PLMA), a photocrosslinkable material derived from human platelet lysates, to produce porous microcarriers. Initially, high quantities of PLMA/alginate core-shell microcapsules are produced using coaxial electrospray. Subsequently, the microcapsules are collected, irradiated with ultraviolet light, washed, and freeze dried yielding PLMA microsponges. These microsponges are able to support the adhesion and proliferation of human adipose-derived stem cells, while also displaying potential in the assembly of autologous microtissues. Cell-laden microsponges were shown to self-organize into aggregates, suggesting possible applications in bottom-up tissue engineering applications. Impact Statement Microcarriers have increasingly been used as delivery platforms in cell therapy. Herein, the encapsulation of human-derived proteins in alginate microcapsules is proposed as a method to produce microcarriers from photopolymerizable materials. The capsules function as a template structure, which is then processed into spherical microparticles, which can be used in cell culture, cell delivery, and bottom-up assembly. As a proof of concept, this method was combined with lyophilization to process methacryloyl platelet lysates into injectable microsponges for cell delivery.

Preparation of Nanofat Concentrate and Its Use for Hypertrophic Scar Treatment

Objective: Nanofat grafting has been reported to improve tissue repair by the Stromal Vascular Fraction (SVF) of nanofat. However, the oil and liquid portions of fat tissues were released by mechanical emulsification during the nanofat procedure. Here, we reported a simple method to remove the oil and water for concentrating nanofat. Methods: The concentrate of nanofat was obtained by processing nanofat using negative pressure produced by syringer and two-step centrifugation. The volume of oil and fat tissue as well as morphological changes of nanofat concetrate obtained by different procedures was examined. Meanwhile, the SVF numbers, the proliferation and differentiation capacity of Adipose-Derived Stem Cells (ADSCs) were determined. The clinical outcome of nanofat concentrate in treatment hypertrophic scar was evaluated. Results: The centrifugation and negative pressure had no significant effect on the proliferation activity of the SVF in the concentrate of nanofat. The concentrated rate after 0, 15, 30 and 60 times of emulsification was 2.08±0.042, 2.63 ± 0.07, 3.8 ± 0.01 and 8.2 ± 0.12 times greater than the original, respectively. The SVF number per 10 ml of fat in the above-mentioned groups were increased by 1.80 ± 0.15, 2.68 ± 0.27, 4.64 ± 0.20 and 3.44 ± 0.27 times, respectively. The capacity of cell proliferation and differentiation decreased significantly after more than 30 times emulsification. The concentrates of nanofat effectively improve the appearence and hardness of hypertrophic scar. Conclusion: The nanofat concentrate prepared by our method include more SVF cells and less oil and might be more effective during clinical use.

3D Bioprinting for Tissue Engineering Amidst the Century Cataclysm

Objective: Nanofat grafting has been reported to improve tissue repair by the Stromal Vascular Fraction (SVF) of nanofat. However, the oil and liquid portions of fat tissues were released by mechanical emulsification during the nanofat procedure. Here, we reported a simple method to remove the oil and water for concentrating nanofat. Methods: The concentrate of nanofat was obtained by processing nanofat using negative pressure produced by syringer and two-step centrifugation. The volume of oil and fat tissue as well as morphological changes of nanofat concetrate obtained by different procedures was examined. Meanwhile, the SVF numbers, the proliferation and differentiation capacity of Adipose-Derived Stem Cells (ADSCs) were determined. The clinical outcome of nanofat concentrate in treatment hypertrophic scar was evaluated. Results: The centrifugation and negative pressure had no significant effect on the proliferation activity of the SVF in the concentrate of nanofat. The concentrated rate after 0, 15, 30 and 60 times of emulsification was 2.08±0.042, 2.63 ± 0.07, 3.8 ± 0.01 and 8.2 ± 0.12 times greater than the original, respectively. The SVF number per 10 ml of fat in the above-mentioned groups were increased by 1.80 ± 0.15, 2.68 ± 0.27, 4.64 ± 0.20 and 3.44 ± 0.27 times, respectively. The capacity of cell proliferation and differentiation decreased significantly after more than 30 times emulsification. The concentrates of nanofat effectively improve the appearence and hardness of hypertrophic scar. Conclusion: The nanofat concentrate prepared by our method include more SVF cells and less oil and might be more effective during clinical use.

Trappc9 Deficiency Impairs the Plasticity of Stem Cells.

Genetic mutations of trappc9 cause intellectual disability with the atrophy of brain structures and variable obesity by poorly understood mechanisms. Trappc9-deficient mice develop phenotypes resembling pathological changes in humans and appear overweight shortly after weaning, and thus are useful for studying the pathogenesis of obesity. Here, we investigated the effects of trappc9 deficiency on the proliferation and differentiation capacity of adipose-derived stem cells (ASCs). We isolated ASCs from mice before overweight was developed and found that trappc9-null ASCs exhibited signs of premature senescence and cell death. While the lineage commitment was retained, trappc9-null ASCs preferred adipogenic differentiation. We observed a profound accumulation of lipid droplets in adipogenic cells derived from trappc9-deficient ASCs and marked differences in the distribution patterns and levels of calcium deposited in osteoblasts obtained from trappc9-null ASCs. Biochemical studies revealed that trappc9 deficiency resulted in an upregulated expression of rab1, rab11, and rab18, and agitated autophagy in ASCs. Moreover, we found that the content of neural stem cells in both the subventricular zone of the lateral ventricle and the subgranular zone of the dentate gyrus vastly declined in trappc9-null mice. Collectively, our results suggest that obesity, as well as brain structure hypoplasia induced by the deficiency of trappc9, involves an impairment in the plasticity of stem cells.

The Importance of Protecting the Structure and Viability of Adipose Tissue for Fat Grafting.

Fat grafting is widely used for soft-tissue augmentation; however, the related clinical outcome remains variable and technique-dependent. The mechanisms underlying fat graft survival are not fully understood, particularly regarding the contributions of different cell types, such as functional adipocytes. This study evaluated the importance of adipose tissue structure and viability in fat grafting and, to some extent, revealed the effect of adipocytes in fat grafting. Human lipoaspirate was harvested using suction-assisted liposuction and processed using three separate methods: cotton-pad filtration, soft centrifugation (400 g for 1 minute), and Coleman centrifugation (1200 g for 3 minutes). Then all samples were subjected to second cotton-pad concentration. Adipose tissue structure and viability, the numbers of adipose-derived stem cells, and their proliferation and multilineage differentiation abilities were compared in vitro. The volume retention rate and fat graft quality were evaluated in vivo. Cell structure destruction and viability decline were more evident in the Coleman centrifugation group compared to the cotton-pad filtration group and the soft centrifugation group. However, no intergroup differences were observed in the numbers, proliferation, or multilineage differentiation abilities of adipose-derived stem cells. After transplantation, the volume retention rates were similar in the three groups. However, greater structural and functional damage was associated with poorer graft quality, including decreased levels of graft viability, vessel density, and vascular endothelial growth factor secretion and increased levels of vacuoles, necrotic areas, fibrosis, and inflammation. Protecting adipose tissue structure and viability is crucial for improving fat grafting outcomes. The protection of the structure and viability of adipose tissue should be ensured throughout the whole process of fat grafting to reduce complications and improve graft quality.

The effect of glycerol as a cryoprotective agent in the cryopreservation of adipose tissue

BackgroundLong-term preservation of adipose tissue is crucial for clinical applications. Researchers should consider both efficiency and biosafety when choosing a cryoprotective agent (CPA) for adipose tissue preservation. Glycerol has been applied as a nontoxic CPA for multiple tissues but not adipose tissue. We aimed to evaluate the efficacy of glycerol as a CPA for adipose tissue cryopreservation.MethodsFresh human adipose tissues were obtained from patients who underwent liposuction and divided into 1 mL samples. Each sample was randomly mixed with 1 mL of CPA: 60–100% glycerol, 0.25 mol/L trehalose or DMSO + FBS and cryopreserved in − 196 °C liquid nitrogen for one month. After thawing and elution, the tissues were immediately evaluated for activity and structural integrity in vitro. Then, 0.2 mL of each sample was transplanted subdermally to the nude mouse dorsum and harvested after one month for histological examination to assess the effect of the cryopreserved fat in transplantation.ResultsAfter cryopreservation, the samples treated with DMSO + FBS, trehalose, 60% and 70% glycerol had a more integrated structure than the samples in other groups. Tissues preserved with 70% glycerol had the highest G3PDH activity of 24.41 ± 0.70, comparable to 24.76 ± 0.48 in fresh tissue (p > 0.05). Adipose-derived stem cells (ASC) viability, proliferation and differentiation capability were also better preserved in 70% glycerol group. In vivo analysis showed that tissue preserved with 70% glycerol had a retention rate of 52.37 ± 7.53%, significantly higher than other groups. Histological observation demonstrated better structural integrity and viability in 70% glycerol group. Compared to the DMSO + FBS and trehalose groups, the glycerol groups showed lower tissue inflammation.ConclusionGlycerol (70%) is efficient in adipose tissue cryopreservation. Glycerol-based CPAs, which are nontoxic and show biosafety, are a promising solution for clinical tissue cryopreservation.

G protein-coupled estrogen receptor 1 mediates proliferation and adipogenic differentiation of goat adipose-derived stem cells through ERK1/2-NF-κB signaling pathway.

Adipose tissue formation and moderate fat deposition are important for the production performance and eating quality of livestock meats. The self-renewal and adipogenic differentiation of adipose-derived stem cells are responsible for the formation and development of adipose tissue. In addition, estrogen targeting G protein-coupled estrogen receptor 1 (GPER1) has been reported to modulate cell proliferation and differentiation during tissue and organ development. However, the potential correlation among estrogen, GPER1, proliferation, and adipogenic differentiation in goat adipose-derived stem cells (gADSCs) is still unclear. Herein, we demonstrated that 17β-estradiol enhances the proliferative ability of gADSCs, indicated by the increased cell number and cell viability, accompanied by up-regulated expressions of cyclin D1 and PCNA. Meanwhile, the adipogenic differentiation is promoted by 17β-estradiol, supported by higher ccumulation of intracellular lipids and increased expressions of PPARγ, ACC, and FABP4. Notably, these activities are all obviously reduced by administration with GPER1 antagonist G15, but GPER1 agonist G1 enhances cell proliferation and adipogenic differentiation. Moreover, GPER1 silencing diminishes cell proliferation and adipogenic differentiation. In parallel, 17β-estradiol elevates the protein level of nuclear p-p65. Furthermore, the phosphorylation of p65 is enhanced by G1 but inhibited by G15 and GPER1 silencing. In addition, the phosphorylation of p65 is mediated by ERK1/2, suggesting that estrogen targeting GPER1 regulates cell proliferation and adipogenic differentiation of gADSCs through the ERK1/2-NF-κB signaling pathway. This study may provide a strong theoretical basis for improving meat quality, flavor, and cold resistance of livestock.

Investigation of polycaprolactone for bone tissue engineering scaffolds: In vitro degradation and biological studies

Polycaprolactone (PCL) is one of the most recognized polymeric materials used for bone tissue engineering scaffold fabrication. This study aims to evaluate the effects of the molecular weight (Mn) of PCL on the degradation kinematics, surface, microstructural, thermal, mechanical, and biological properties of 3D printed bone scaffolds. Surface properties were investigated considering water-in-air contact angle and nanoindentation tests, while morphological characteristics and degradation kinematics (accelerated degradation tests) were examined using scanning electron microscopy (SEM), pairing with thermal and mechanical properties monitored at each considered time point. A set of mathematical equations describing the variation of fiber diameter, porosity, mechanical properties, and weight, as a function of molecular weight and degradation time, were obtained based on the experimental results. Human adipose-derived stem cells (hADSCs) proliferation and differentiation tests were also conducted using in vitro colorimetric assay. All results indicated that molecular weight had impacts on the surface, mechanical and biological properties of PCL scaffolds, while no significant effects were observed on the degradation rate. Scaffolds with lower molecular weight presented better bio-mechanical properties. These findings provide useful information for the design of polymeric bone tissue engineering scaffolds.

Injectable adipose-derived stem cells-embedded alginate-gelatin microspheres prepared by electrospray for cartilage tissue regeneration.

ObjectiveTo prepare adipose-derived stem cells (ADSCs)-embedded alginate-gelatinemicrospheres (Alg-Gel-ADSCs MSs) by electrospray and evaluate their feasibility for cartilage tissue engineering. To observe the efficacy of Alg-Gel-ADSCs MSs in repairing articular cartilage defects in SD rats.MethodsADSCs were isolated and characterized by performing induced differentiation and flow cytometry assays. Alginate-gelatine microspheres with different gelatine concentrations were manufactured by electrospraying, and the appropriate alginate-gelatine concentration and ratio were determined by evaluating microsphere formation. Alg-Gel-ADSCs MSs were compared with Alg-ADSCs MSs through the induction of chondrogenic differentiation and culture. Their feasibility for cartilage tissue engineering was analysed by performing Live/Dead staining, cell proliferation analysis, toluidine blue staining and a glycosaminoglycan (GAG) content analysis. Alg-Gel-ADSCs MSs were implanted in the cartilage defects of SD rats, and the cartilage repair effect was evaluated at different time points. The evaluation included gross observations and histological evaluations, fluorescence imaging tracking, immunohistochemical staining, microcomputed tomography (micro-CT) and a CatWalk evaluation.ResultsThe isolated ADSCs showed multidirectional differentiation and were used for cartilage tissue engineering. Using 1.5 w:v% alginate and 0.5 w:v% gelatine (Type B), we successfully prepared nearly spherical microspheres. Compared with alginate microspheres, alginate gel increased the viability of ADSCs and promoted the proliferation and chondrogenesis of ADSCs. In our experiments on knee cartilage defects in SD rats in vivo, the Alg-Gel-ADSCs MSs showed superior cartilage repair in cell resides, histology evaluation, micro-CT imaging and gait analysis.ConclusionsMicrospheres composed of 1.5 w:v% alginate-0.5 w:v% gelatine increase the viability of ADSCs and supported their proliferation and deposition of cartilage matrix components. ADSCs embedded in 1.5 w:v% alginate-0.5 w:v% gelatine microspheres show superior repair efficacy and prospective applications in cartilage tissue repair.The translational potential of this articleIn this study, injectable adipose-derived stem cells-embedded alginate-gelatin microspheres (Alg-Gel-ADSCs MSs) were prepared by the electrospray . Compared with the traditional alginate microspheres, its support ability for ADSCs is better and shows a better repair effect. This study provides a promising strategy for cartilage tissue regeneration.

Three-dimensional printing of chitosan cryogel as injectable and shape recoverable scaffolds

Cryogel has macroporous structure and advantages of mechanical stability and injectability for biomedical applications. Three-dimensional (3D) printing is a customized manufacturing technology. However, there is little research on 3D printing of cryogel. In this work, we developed a 3D-printable chitosan cryogel using difunctional polyurethane nanoparticles as the crosslinker that reacted with chitosan at 4 °C for 4 h to form a stable feeding hydrogel (pre-cryogel) for 3D printing. The printed pre-cryogel was frozen at −20 °C to form 3D-printed chitosan cryogel. The 3D-printed cryogel had properties similar to those of bulk cryogel such as high compressibility, elastic recovery, and water absorption (≈3200%). Results from cell experiments indicated that the 3D-printed chitosan cryogel scaffolds provided good mechanical integrity for proliferation and chondrogenic differentiation of human adipose-derived adult stem cells. The 3D-printed chitosan cryogel scaffolds with injectability and shape recovery property are potential biomaterials for customized tissue engineering and minimally invasive surgery.

Application of Platelet-rich Plasma (PRP) with Different Scaffolds in Tissue Engineering

Background: Today, stem cells are the best candidates for cell therapy and tissue engineering. Adipose-derived Stem Cells (ADSCs) are an essential source of cells in replacement therapies of many diseases. Objectives: This study compared the proliferation of ADSCs in alginate and fibrin scaffolds. Methods: Adipose-derived stem cells were isolated from adipose tissue and cultured in alginate or fibrin scaffolds with a medium containing PRP 10% or FBS 10%. Then, the cell viability percentage was assessed by MTT assay and trypan blue staining. Also, the percentages of living, apoptotic, and necrotic cells were assessed by flow cytometry assay on the fourth and eighth days. Results: The cell viability rate was significantly higher in the fibrin scaffold group with PRP than in other groups on the fourth and eighth days (P < 0.05). Moreover, the rate of necrotic cells was significantly lower in the fibrin scaffold group than in the other groups (P < 0.05). Besides, the percentage of living cells was significantly higher in the fibrin scaffold group with PRP than in the other groups on the fourth and eighth days (P < 0.05). Also, the percentage of early apoptotic cells was significantly lower in fibrin with PRP than in other groups on the fourth day. There was no significant difference in the rate of late apoptotic cells between the groups (P > 0.05). Conclusions: These findings indicate the positive effect of PRP on the survival and proliferation of ADSCs compared with FBS. Therefore, PRP can be considered a suitable supplement to replace animal sera like FBS.

Oral administration of megestrol acetate can increase fat graft survival in a rat model

Insufficient and inconsistent survival is a significant shortcoming of fat grafts. Reportedly, megestrol acetate (MA) could induce proliferation, migration, and adipogenic differentiation of adipose-derived stem cells in vitro. Thus, we tested whether MA could promote fat graft survival in a rat model. Twenty-eight Sprague-Dawley rats (8 weeks old, male) were divided into two groups: experimental (MA group, n=14) and control (n=14). The inguinal fat pad (1g) was extracted en bloc and re-implanted under the scalp in both groups. MA (100mg/kg/day) was administered orally for 14 postoperative days in the experimental group. After 6 weeks, the volume and weight of the grafted fat were measured. Histologic examination with hematoxylin and eosin (HE) and real-time polymerase chain reaction (PCR) for vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2), and CCAAT/enhancer-binding protein alpha (C/EBP-α) were performed. Perilipin staining was performed to check the viability of grafted fat. Graft fat volume was greater in the MA group, compared with that in the control (P=0.023). The MA group also had more viable cells, including more adipocytes, and less fibrosis or vacuoles than the control on HE and perilipin staining. MA upregulated the expression of FGF2 (P<0.001), VEGF (P=0.008), and C/EBP-α (P=0.002) at the second postoperative week. MA increased survival of grafted fat in an animal model. Increased vascularization and adipogenesis were related to these results. Further human clinical trials are necessary to evaluate adjunctive oral administration of MA after fat grafting to promote graft survival.

Dermal Papilla Cell-Derived Extracellular Vesicles Increase Hair Inductive Gene Expression in Adipose Stem Cells via β-Catenin Activation.

Recently, extracellular vesicle (EV)-mediated cell differentiation has gained attention in developmental biology due to genetic exchange between donor cells and recipient cells via transfer of mRNA and miRNA. EVs, also known as exosomes, play a role in maintaining paracrine cell communication and can induce cell proliferation and differentiation. However, it remains unclear whether adipose-derived stem cells (ASCs) can adopt dermal papilla (DP)-like properties with dermal papilla cell-derived extracellular vesicles (DPC-EVs). To understand the effect of DPC-EVs on cell differentiation, DPC-EVs were characterized and incubated with ASCs, of monolayer and spheroid cell cultures, in combination with the CAO1/2FP medium specialized for dermal papilla cells (DPCs). DPC-like properties in ASCs were initially evaluated by comparing several genes and proteins with those of DPCs via real-time PCR analysis and immunostaining, respectively. We also evaluated the presence of hair growth-related microRNAs (miRNAs), specifically mir-214-5P, mir-218-5p, and mir-195-5P. Here, we found that miRNA expression patterns varied in DPC-EVs from passage 4 (P4) or P5. In addition, DPC-EVs in combination with CAP1/2FP accelerated ASC proliferation at low concentrations and propagated hair inductive gene expression for versican (vcan), alpha-smooth muscle actin (α-sma), osteopontin (opn), and N-Cam (ncam). Comparison between the expression of hair inductive genes (vcan, α-sma, ctnb, and others), the protein VCAN, α-SMA and β-Catenin (CTNB), and hair inductive miRNAs (mir-214-5P, mir-218-5p, and mir-195-5p) of DPC-EVs revealed similarities between P4 DPC-EVs-treated ASCs and DPCs. We concluded that early passage DPC-EVs, in combination with CAP1/2FP, enabled ASCs to transdifferentiate into DPC-like cells.

Advanced platelet-rich fibrin promotes the paracrine function and proliferation of adipose-derived stem cells and contributes to micro-autologous fat transplantation by modulating HIF-1α and VEGF

BackgroundThe micro-autologous fat transplantation (MAFT) technique has demonstrated its feasibility in multiple medical fields, such as facial rejuvenation. Advanced platelet-rich fibrin (APRF), an autologous platelet concentrated on a fibrin membrane without added external factors, has shown significant potential for tissue restoration. However, the role of APRF in the modulation of MAFT remains unclear. Here, we aimed to explore the effect of APRF on MAFT.MethodsAdipose-derived stem cells (ASCs) were isolated from human gastric subcutaneous fat and treated with APRF. ELISA assays measured cytokines. The proliferation of ASCs was analyzed by CCK-8 assays. The levels of hypoxia-inducible factor-1α (HIF-1α), heat shock protein 70 (HSP70), insulin like growth factor 2 (IGF-2), interleukin-6 (IL-6), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) were measured by ELISA assays, quantitative reverse transcription-PCR (qRT-PCR), and Western blot analysis. The effect of APRF/HIF-1α/VEGF on MAFT in vivo was analyzed in Balb/c nude mice. The BALB/c mice were subcutaneously co-transplanted with fat, APRF, and control shRNA, HIF-1α shRNA, or VEGF shRNA into the dorsal area. The serum and protein levels of the above cytokines were analyzed by ELISA assays and Western blot analysis. Lipid accumulation was measured by Oil Red O staining. The expression of CD34 was assessed by immunohistochemical staining.ResultsAPRF continuously secreted multiple cytokines, including epidermal growth factor (EGF), FGF-2, insulin like growth factor 1 (IGF-1), interleukin-1beta (IL-1β), interleukin-4 (IL-4), platelet-derived growth factor alpha polypeptide b (PDGF-AB), platelet-derived growth factor beta polypeptide b (PDGF-BB), transforming growth factor-beta (TGF-β), and VEGF. APRF was able to promote the proliferation of ASCs. APRF dose-dependently activated the expression of HIF-1α, HSP70, IGF-2, IL-6, IL-8, and VEGF in ASCs. APRF regulated the paracrine function of ASCs by modulating HIF-1α and VEGF. APRF increased the survival of MAFT by modulating HIF-1α and VEGF in vivo.ConclusionsAPRF promotes the paracrine function and proliferation of ASCs and contributes to MAFT by modulating HIF-1α and VEGF. Our findings provide new insights into the mechanism by which APRF regulates MAFT.