Dirty surface - Cleaner cells? Some observations with bio-assembled extracellular matrices

Abstract

Conventional propagation of mesenchymal stem cell (MSC) on tissue culture polystyrene (TCPS) decreases their self-renewal capacity and drives them into senescence. Human embryonic stem cells (hESC) cannot be propagated on TCPS at all and require feeder layers or MatrigelTM, both of which introduce a xenogenic threat. Obviously, these platforms do not emulate the physiological stem cell microenvironment, consisting of soluble factors, neighbouring cells and a complex extracellular matrix (ECM). We directed ECM deposition by human fibroblasts through application of macromolecular crowding followed by detergent lysis to achieve a cell-free matrix. Long-term propagation of MSCs for 58 days on these bioassembled matrices increased their population doublings by 79% compared to TCPS controls. In addition, these MSCs showed a better retention of adipogenic differentiation capability. HESCs cultured on these matrix in combination with a chemically defined medium for more than 13 passages and showed 40% more population doublings compared to MatrigelTM cultures. Matrix-propagated hESCs maintained a desirable morphology and growth pattern and retained the expression of pluripotency markers. These cells were able to form teratomas in SCID mice, while exhibiting normal karyotypes. The application of macromolecular crowding to create bioassembled human matrices shows great promise in the propagation of MSCs or hESCs. © 2011 Springer-Verlag.