Colonization and maintenance of murine embryonic stem cells on poly( α-hydroxy esters)

The aim of this study was to determine the ability of various poly( α-hydroxy esters) to support the in vitro propagation of murine embryonic stem (ES) cells in an undifferentiated state. To this end, ES cell colonization, growth and Oct-4 immunoreactivity following a 48 h culture period upon poly( d,l -lactide), poly( l -lactide), poly(glycolide) and poly( d,l -lactide- co-glycolide) (PLGA) were assessed. By the analysis of live and dead cell number indices and Oct-4 immunoreactivity, ES cell colonization rate during a 48 h culture period was found to be significantly greater on PLGA compared to all the other unmodified poly( α-hydroxy esters) tested. Surface treatment of all polymers with 0.1 m potassium hydroxide revealed a significant increase in ES cell live numbers when compared to all unmodified polymers, thus revealing a correlation between polymer content, hydrophilicity and colonization rate. These data suggest that surface treated poly( α-hydroxy esters) may be employed for ES cell scale up procedures and in tissue engineering applications requiring the colonization of scaffolds by ES cells in an undifferentiated state. According to such applications, once the designated scaffold has been colonized, ES cell directed differentiation into the desired and fully differentiated, functional adult tissue may then be effected.