Papers by Keyword: Adipose Tissue-Derived Stem Cells

Abstract: The purpose of this study is to confirm the possibility of regenerating actual fat tissue using human adipose tissue-derived stem cells (ASCs) and hyaluronic acid-collagen sponge in animal model. Human ASCs of young female adults were isolated and culture expanded in basal media. At the second passage, cultured ASCs suspension containing 106 cells was applied on prewetted scaffolds the hyaluronic acid-collagen sponge and the sponges was exposed to adipogenic media for the 1week. Then the tissue engineered constructs were implanted into the subcutaneous pocket on the back of immunodeficient athymic nude mice for 3 weeks. Hyaluronic acid-collagen sponges without human ASCs were used as the control. After 3 weeks, specimens were harvested and adipogenic potentials were assessed with histological examination, RT-PCR for PPAR-γ2 expression and G-3-PDH activity. Tissue engineered fat tissue from ASCs and hyaluronic acid-collagen sponges demonstrated PPAR-γ2 positive expression and positive Oil red O staining. The histologic study showed definitive adipose tissue and rich vascular tissue within the engineered fat. Two-fold higher activities of G-3-PDH were identified in experimental group after 3 weeks as compared to control. By contrast, the specimen from control group did not show active vessel ingrowth and contained only few cellular elements within the scaffold. The control specimens failed to demonstrate adipogenic gene markers and were negative in oil red O staining. In conclusion, human ASCs can be differentiated into adipocytes and actual fat tissue engineering was possible with combination of adequate scaffold materials, such as hyaluronic acid-collagen sponges. These data demonstrate that fat tissue engineered from human ASCs can retain predefined shape and dimension for soft tissue augmentation and reconstruction of defects.

Abstract: Fibrin is a natural substrate for growth, adhesion, and migration of mature endothelial cells (ECs) and a candidate coating material in approaches to graft endothelialization. Adipose tissue represents an abundant, practical source of donor tissue for stem cells which may be a useful source for engineering of vascular grafts. However, the optimal substrates that promote differentiation of adipose tissue-derived stem cells (ASCs) into ECs remain to be elucidated. In the present study, we investigated whether fibrin can be used as a substratum to support in vitro ECs differentiation of ASCs and whether fibrinogen concentration can be affect on ECs differentiation of ASCs. For determination of phenotypic characteristics of ASCs used in this experiment, we performed flow cytometry analysis. ASCs were plated on fibrin composed of varying concentrations of fibrinogen and induced into ECs differentiation in presence of VEGF. Before inducing into ECs, ASCs did not express any markers of hematopoietic cells (CD34, CD45), ECs (CD31, CD34), and endothelial progenitor cells (CD34, CD133, Flk-1). The degree of ECs differentiation was determined by capillary network formation, ECs-specific gene expression, and F-actin assembly. During the first 12 h after seeding, cells spread randomly, moved and formed small interconnected clusters. These clusters decreased in size and formed a capillary tube at 48 h. During the further incubation in presence of VEGF for 7 days, ASCs expressed mRNA and protein of von Willebrand factor (vWF). The degree of ECs differentiation of ASCs was consistently decreased as fibrinogen concentration increase. Fibrin may be used as biomatrix to promote differentiation of ASCs into ECs for tissue engineering.