Studies on the development of biomimetic microenvironment for stem cell culture

Abstract

This study examined to deveolop of three-dimensional (3D) culture system for in vitro culture of mouse embryonic stem cells (mESCs) and human adipose derived stromal cells (hADSCs) in biomimetic, non-cellular microenvironment. <br/> I assumed that every different type of stem cells need customized condition of microenvironment for themselves in biomimetic culture system. Development of 3D microenvironment were performed for mESCs and hADSCs and their result were compared. <br/> As the first step in this study, I analyzed oocyte isolation and development method to obtain quality oocytes from young and old aged mice. For the second step, I screened the integrin expression on the surface of inbred R1 and hybrid B6D2F1 mouse ESCs to analyze cell to cell/ECM interaction before construct biomimetic microenvironment. After functional analysis of integrin heterodimers, I confirmed that the integrin heterodimers α6β1 and αVβ1 actively functioned on the surface of undifferentiated mESCs of both strains. For the next step, to construct a biomimetic microenvironment customized to self-renewal and proliferation of mESCs, I evaluated whether the different types of mESCs needs the different conditions of three-dimensional (3D) synthetic scaffolds for cell self-renewal. In this step, mechanical strength of microenvironment were varied and different mESCs showed different aspects of cellular reactivity in microenvironment, which means each cell line requires customization for the mechanical properties of microenvironment.<br/> For hADSCs, similar-but little bit different- process were performed. hADSCs were isolated from adipose tissue and stabilized by MACS separation and culture process. Transcriptional and translational analysis showed hADSCs expressed α5, αV, and β1 subunits when conventional culture methods. This information provided different combination of integrin heterodimers which refers hADSC need different 3D condition than mouse ESCs for suitable culture. Accordingly, suitable mechanical strength of microenvironment for hADSCs were different than any of mESC lines. <br/> In these studies, every cell lines needed different condition of biomimetic microenvironment for suitable culture condition. Establishment of stabilized biomimetic microenvironment culture system for stem cells will contribute to develop bio-mimetics in in vitro and contribute to novel clinical stem cell therapies and researches.<br/>