Objective Seed cells are the hotspot of tissue engineering research. To study the seed cells with high potential of adipogenic differentiation for applying the adipose tissue engineering and increasing the constructing efficiency of adipose tissue engineering. Methods Mature adipocytes (MA) and adipose-derived stromal cells (ADSCs) were harvestedfrom human fat aspirates via l iposuction by collagenase digestion. MA were cultured and induced to dedifferentiated adipocytes (DA) by ceil ing adherent culture method. DA and ADSCs were induced to adipogenic differentiation. The adipogenic abil ities of DA and ADSCs were compared by inverted phase contrast microscope observation, absorption spectrometry assay of oil red O staining, and cell counting of oil red O staining. Results MA could dedifferentiate into fibroblast-shaped DA. After adi pogenic differentiation, the inverted phase contrast microscope observation showed that there were much more l i pid droplet in DA than in ADSCs. Absorption spectrometry assay of oil red O staining showed there were significant l ipid droplet aggregation in DA 4 days of adipogenic induction. However, the same phenomenon could be observed in ADSCs at 10 days after differentiation. After 12 days, the absorption value of DA was higher than that of ADSCs, showing significant difference (P lt; 0.05). The cell counting of oil red O staining demonstrated that the adipogenic rates of DA and ADSCs were 65% ± 6% and 35% ± 5%, respectively, showing significant difference (P lt; 0.05). Conclusion The potential of adipogenic differentiation of DA is ber than that of ADSCs. DA is a promising seed cell of adipose tissue engineering.
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 summarize recent progress in adipose tissue acting as a more efficient and ideal therapy to facilitate wound repair and evaluate the therapeutic values of adipose tissue.MethodsThe related literature about adipose tissue for wound healing in recent years was reviewed and analyzed.ResultsEnormous studies focus on the capacity of adipose tissue to accelerate wound healing including cellular components, extracellular matrix, and paracrine signaling have been investigated.ConclusionAdipose tissue has generated great interest in recent years because of unique advantages such as abundant and accessible source, thriven potential to enhance the regeneration and repair of damaged tissue. However, there is still a need to explore the mechanism that adipose tissue regulates cellular function and tissue regeneration in order to facilitate clinical application of adipose tissue in wound healing.
Objective To review the research status of the neovascularization of adi pose tissue engineering in the past decade so as to provide theoretical references for the development of the rapid revascularization of tissue engineered adi pose. Methods The l iterature about the revascularization of adi pose tissue engineering was extensively reviewed andanalyzed, centering on 5 elements: specificity of histological structures and blood supply, revascularization mechanism, coculture of different seed cells, modification of scaffold, and microenvironment. Results Adi pose tissue engineering offers a new solution for soft tissue defects. However, there is still the unfulfilled need in the size of engineered adipose tissue (less than 1 mL), which was determined by the degree of neovascularization in engineered tissue. Overall, rapid neovascularization in engineering tissue is a key l ink of experimental study changing into cl inical appl ication. Conclusion Providing a sufficient supply with nutrients and oxygen by means of a sufficient and rapid neovascularization will be at the heart of any attempts to obtain bigger tissue engineered adipose to meet the demand of repairing large soft tissue defect.
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.
ObjectiveTo study effect of expression levels of serum inflammatory factors and insulin receptor substrate(IRS)-1/2 in visceral adipose tissue after Roux-en-Y gastric bypass(RYGB) on type 2 diabetes mellitus(T2DM) rats, and explore possible mechanism in treatment of T2DM. MethodsThe T2DM rats models were established, which were divided into 3 groups by intervention: T2MD-RYGB group(n=14), T2MD-sham operation(T2MD-SO) group(n=10), and T2MD group(n=10), and 10 normal rats were selected as control group. The rats of the T2MD-RYGB group were received the RYGB, and of the T2MD-SO group were received transection and reanastomosis of the gastroin-testinal tract. The fasting plasma glucose(FPG), fasting insulin(FINS), C-reaction protein(CRP), tumor necrosis factor-α(TNF-α), free fatty acid(FFA), homestasis model assessment for insulin resistance(HOMA-IR), adipose tissue insulin resistance(Adipo-IR) were tested respectively before operation and on week 1, 4, 8 after operation(synchronous detec-tion of rats with or without surgical intervention). The IRS-1 and IRS-2 protein contents of the rat epididymal adipose tissue were tested on week 8 after operation. ResultsThe FPG, FINS, CRP, TNF-α, FFA levels, and HOMA-IR, Adipo-IR indexes in the T2DM rats were significantly higher than those in the normal rats(P < 0.05) before operation, the above indicators on week 4, 8 after operation were significantly lower than those before operation in the T2MD-RYGB group(P < 0.05). The differences of changes among the other groups were not statistically significant(P > 0.05). The IRS-1 and IRS-2 protein expressions in the adipose tissue of the rats were significantly increased in the T2MD-RYGB group as compared with these indicators in the T2MD group and T2MD-SO group(P < 0.05), but which were significantly lower than those in the control group(P < 0.05). ConclusionsRYGB could increase IRS-1/2 expression levels in adipose tissue, which could enhance insulin sensitivity, decrease serum inflammatory factors levels, and improve insulin resistance ultimately. This might be one of the mechanisms in treatment of T2DM.
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.
ObjectiveTo evaluate the mechanism of stromal vascular fraction (SVF) promoting angiogenesis and tissue regeneration in tissue engineering chamber. MethodsTwenty-four 6-month-old New Zealand white rabbits, male or female, weighing 2.5-2.8 kg, were selected. Thoracic dorsal arteriovenous bundle combined with collagen type I scaffold was transplanted to dorsal side, and wrapped by cylindrical hollow silicone chamber; all animals were randomly divided into the experimental group (n=12) and the control group (n=12). SVF was isolated from the back fat pads of rabbits in experimental group and labelled with DiI at 2 weeks after operation. The 1 mL cell suspension (1×106 cells/mL) and equal saline were injected into the chamber in experimental group and control group, respectively. The regenerative tissues were harvested for general observation and HE staining at 2 and 4 weeks after injection;and immunofluorescent staining was carried out in experimental group at 4 weeks. ResultsAt 2 weeks after injection, the regenerative tissue was cylindrical; obvious vessel network and incompletely degradable collagen scaffold could be seen on the surface of the new tissue in 2 groups. The volume of new tissue was (0.87±0.11) mL in experimental group, and (0.72±0.08) mL in control group at 2 weeks, showing significant difference (t=2.701, P=0.011). At 4 weeks, little collagen scaffold could be seen on the surface in control group, but no collagen scaffold in experimental group; the volume of new tissue was (0.74±0.14) mL in experimental group, and (0.64±0.10) mL in control group, showing no significant difference (t=1.424, P=0.093). HE staining showed new mature vessels at 4 weeks, but no adipose tissue or fat lobulus formed in both groups; the capillary density was significantly higher in experimental group than in control group at 2 weeks (t=6.291, P=0.000) and at 4 weeks (t=5.445, P=0.000). The immunofluorescent staining found that SVF survived and located at the edge area after 4 weeks; the expressions of CD31 and DiI were positive in some endothelial cells. ConclusionSVF can promote the angiogenesis and tissue regeneration in tissue engineering chamber, but it can not differentiate into adipocyte spontaneously without adipogenic microenvironment.
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.