Papers by Author: Ji Yeon Seo

Abstract: New strategies to make cultured fibroblasts grafts more appealing are aimed at reducing the time spent in culture and improving the handling and biologic properties. In the present study, we developed a simple and effective method to fabricate dermal fibroblasts-populated membrane based on (1) the use of fibrin as a 3-dimensional matrix and (2) the use of cell- mediate contraction to make a self assembled, detachable cells-populated membrane. Human dermal fibroblasts were cultured by explants method. The fibroblasts encapsulated in fibrin were transferred into 6-well culture plates which pretreated with Sigmacoat® to prevent cell binding on surface of culture dish. Fibroblasts populated fibrin matrix (FPFM) was cultured in attached condition for 7 days and in free floating condition for 1 day. The FPFM were contracted, spontaneously released from culture plate, compacted, and formed tissue-like membrane. The fabricated FPFM revealed uniformly distributed cells and newly synthesized extracellular matrix was deposited in matrix. FPFM could successfully graft into full-thickness cutaneous defect of nude mice, and showed significantly increased wound closure rate. Our results demonstrate that the FPFM membrane delivery system allows for restoration of both the epidermal and dermal compartments.

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.