ObjectiveTo summarize the isolation procedures, molecular characterization, and differentiation and vascularization capacity of adipose-derived stem cells (ADSCs), in order to discuss the potential value of ADSCs for the repairment and regeneration of adipose tissues. MethodsRelated literatures about ADSCs were retrieved to summarize the potential value of ADSCs for the repairment and regeneration of adipose tissues. ResultsAs mesenchymal stem cells, ADSCs was rich in human adipose tissues. ADSCs possessed the potential to differentiate toward a variety of cell lineages, such as adipogenic, chondrogenic, osteogenic, cardiomyogenic, myogenic, and angiogenic. Besides, its capacity of adipogenic differentiation could maintain several passages. The most importantly, ADSCs could secrete significant amounts of angiogenesis-related cytokines, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2), which increased the angiogenesis of adipose tissue. ConclusionsADSCs play a key role in adipose tissue engineering, autologous adipose tissue grafting, and soft tissue wound repairing, which have important application prospect for breast reconstruction.
ObjectiveTo investigate the necessity of subcutaneous suture for gynecologic abdominal incision, and to prove the clinical value of suture without subcutaneous ligature. MethodsWe retrospectively studied the clinical data of 210 cases of gynecologic abdominal incision treated between May 2010 and May 2013. A total of 111 cases had the suture without subcutaneous ligature and 99 received the traditional suture. ResultsOne patient (0.90%) had fat liquefaction in the group of suture without subcutaneous ligature, while 7 (7.07%) of fat liquefaction were found in the traditional suture group, and the difference was statistically significant (χ2=3.883, P=0.049). No hospital infection occurred. The healing period averaged (15.1±4.7) days, and the patients were followed up for 2 months without any complication of abdominal incision in all the patients. ConclusionSuture without subcutaneous ligature is simple and easy to practice, with precise effect, which deserves clinical application.
Objective To review research progress of adipose tissuederived stromal cells (ADSCs).Methods The recent articles on ADSCs were extensively reviewed, and the culture and differentiation ability of ADSCs were investigated.Results A population of stem cells could be isolated from adult adipose tissue, they were processed to obtain a fibroblast-like population of cells and could be maintained in vitro for extended periods with stable population doubling. The majority of the isolated cells were mesenchymal origin, with a few pericytes,endothelial cells and smooth muscle cells. ADSCs could be induced to differentiate intomultiple mesenchymal cell types, including osteogenic, chondrogenic, myogenic and adipogenic cells, they could also differentiate into nerve cells.Conclusion ADSCs can substitute mesenchymal stem cells and become an alternative stem cells source for tissue engineering.
ObjectiveTo 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.MethodsThe 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.ResultsAfter 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).ConclusionDAT 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.
Objective To investigate the possibility of theadipose tissue-derived stromal cells(ADSCs) to differentiate into the neuron-like cells and to explore a new cell source for the transplantation related to the central nervous system. Methods Adipose was digested by collagenase, cultured in the fetal bovine serum containing a medium. Trypse was used to digest the cells and the cell passage was performed. The 3rd to the 9th passage ADSCs were used to make an induction. Isobutylmethylxanthine, indomethacin, insulin, and dexamethasone were used to induce the ADSCs to differentiate into the neuron-like cells and adipocytes. Sudan black B and immunocytochemistry were used to identify the cells. Results A population of the ADSCs could be isolated from the adult human adipose tissue, they were processed to obtain a fibroblast-like population of the cells and could be maintained in vitro for an extendedperiod with the stable population doubling, and they were expanded as the undifferentiated cells in culture for more than 20 passages, which indicated their proliferative capacity. They expressed vimentin and nestin, and characteristics of the neuron precursor stem cells at an early stage of differentiation. And the majority of the ADSCs also expressed the neuron-specific enolase and βⅢ-tubulin, characteristics of the neurons. Isobutyl-methyxanthine, indomethacin, insulin, and dexamethasone induced 40%-50% of ADSCs to differentiate into adipocytes and 0.1%0.2% of ADSCs into neuron-like cells. The neuron-like cells had a complicated morphology of the neurons, and they exhibited a neuron phenotype, expressed nestin, vimentin, neuron-specific enolase and βⅢ-tubulin, but some neuron-like cells also expressed thesmooth muscle actin (SMA), and the characteristics of the smooth muscle cells; however, the neurons from the central nervous system were never reported to express this kind of protein. Therefore, the neuron-like cells from the ADSCs could be regarded as functional neurons. Conclusion Ourresults support the hypothesis that the adult adipose tissue contains the stem cells capable of differentiating into the neuron-like cells, and they can overcome their mesenchymal commitment, which represents an alternative autologous stemcell source for transplantation related to the central nervous system.
Objective Extracellular matrix is one of the focus researches of the adi pose tissue engineering. To investigate the appropriate method to prepare the porcine skeletal muscle acellular matrix and to evaluate the biocompatibility of the matrix. Methods The fresh skeletal muscle tissues were harvested from healthy adult porcine and were sl iced into2-3 mm thick sheets, which were treated by hypotonic-detergent method to remove the cells from the tissue. The matrix was then examined by histology, immunohistochemistry, and scanning electron microscopy. The toxic effects of the matrix were tested by MTT. Human adi pose-derived stem cells (hADSCs) were isolated from adi pose tissue donated by patients with breast cancer, and identified by morphology, flow cytometry, and differentiation abil ity. Then, hADSCs of passage 3 were seeded into the skeletal muscle acellular matrix, and cultured in the medium. The cellular behavior was assessed by calcein-AM (CA) and propidium iodide (PI) staining at 1st, 3rd, 5th, and 7th days after culturing. Results Histology, immunohistochemistry, and scanning electron microscopy showed that the muscle fibers were removed completely with the basement membrane structure; a large number of collagenous matrix presented as regular network, porous-like structure. The cytotoxicity score of the matrix was grade 1, which meant that the matrix had good cytocompatibil ity. The CA and PI staining showed the seeded hADSCs had the potential of spread and prol iferation on the matrix. Conclusion Porcine skeletal muscle acellular matrix has good biocompatibility and a potential to be used as an ideal biomaterial scaffold for adi pose tissue engineering.
ObjectiveTo prepare human acellular adipose tissue matrix and to evaluate the cellular compatibility so as to explore a suitable bio-derived scaffold for adipose tissue engineering. MethodsThe adipose tissue was harvested from abdominal skin graft of breast cancer patients undergoing radical mastectomy or modified radical mastectomy, and then was treated with a series of decellularization processes including repeated freeze-thaw, enzyme digestion, and organic solvent extraction. The matrix was examined by histology, immunohistochemistry, DAPI fluorescence staining, and scanning electron microscopy to observe the the removal of cells and to analyze its composition of collagen type IV, laminin, and fibronectin, and microstructure. The 3rd passage human adipose-derived stem cells (hADSCs) were co-cultured with acellular adipose tissue matrix and different concentrations of extracted liquid (100%, 75%, 50%, and 25%). The cytotoxic effects of the matrix were tested by MTT. The biocompatibility of the matrix was detected by live/dead staining and scanning electron microscopy observation. ResultsThe acellular adipose tissue matrix basically maintains intrinsical morphology. The matrix after acellular treatment consisted of extracellular matrix without any cell components, but there were abundant collagen type I; neither DNA nor lipid residual was detected. Moreover, the collagen was the main component of the matrix which was rich in laminin and fibronectin. At 1, 3, and 5 days after co-cultured with hADSCs, the cytotoxic effect of matrix was grade 0-1. The matrix displayed good cell compatibility and proliferation. ConclusionThe acellular adipose tissue matrix prepared by repeated freeze-thaw, enzyme digestion, and organic solvent extraction method remains abundant extracellular matrix and has good cellular compatibility, so it is expected to be an ideal bio-derived scaffold for adipose tissue engineering.
Objective To summarize the donor factors and experimental factors that affect adipogenic differentiation of adipose derived stem cells, so as to provide reference for adipogenic differentiation of adipose derived stem cells. Methods The related research literature about donor factors and experimental factors affecting adipogenic differentiation of adipose derived stem cells in recent years was extensively reviewed and summarized. Results There are a lot of donor factors and experimental factors affecting adipogenic differentiation of adipose derived stem cells, but some of the factors are still controversial, such as donor age, health status, adipose tissue of different parts, and so on. These factors need to be further studied. Conclusion The donor factors and experimental factors that affect adipogenic differentiation of adipose derived stem cells should be deeply studied and the controversial issues should be clarified to lay a solid foundation for the application of adipose derived stem cells in adipose tissue engineering.
Objective To summarize applications and research progress of common magnetic resonance imaging lipid detection techniques in abdomen and pelvis. Method The latest domestic and foreign research literatures related to the applications and research progress of common magnetic resonance imaging lipid detection techniques in the abdomen and pelvis in recent years were collected and reviewed. Results The fat-selective spectral-spatial imaging, 1H-magnetic resonance spectroscopy (1H-MRS), and Dixon & IDEAL are three main magnetic resonance imaging lipid detection techniques, and they can estimate the fat content in the normal tissues and lesions noninvasively and longitudinally, which make the ectopic fat-induced diseases’ early diagnosis, treatment and follow-up possible. Conclusion Magnetic resonance imaging lipid detection techniques have obvious clinical values in quantitative measurement of fat content, and each method gets its own advantage, especially modified Dixon, which is more convenient and accurate and shows an enormous potential in clinical practice.