PLGA doping of PCL affects the plastic potential of human mesenchymal stem cells, both in the presence and absence of biological stimuli.

A range of poly epsilon-caprolactone (PCL) films mixed/doped with poly(lactide-co-glycolide) (PLGA) (65:35) in 0, 10, 20, and 30 wt % were produced, sterilized using ethylene oxide, and analyzed using FTIR. Characterized human mesenchymal stem cells (hMSCs) were cultured in contact with the materials in basal, chondrogenic, and osteogenic medium for time periods up to 28 days, to determine if the materials could induce differentiation of MSC both in the presence and absence of biological stimuli. Viable cell adhesion was analyzed under all conditions. Collagen I, collagen II, sox-9, osteocalcin, osteopontin, osteonectin, and CBFA1 were evaluated at both the mRNA (real-time PCR) and protein production levels (fluorescent immunohistochemistry) and used to identify cell differentiation. Pure PCL and PCL mixed with PLGA demonstrated a chondrogenic potential. Only PCL 8 (80 wt % PCL, 20 wt % PLGA) facilitated osteogenic differentiation of MSCs under osteogenic conditions. This was attributed to the increased hydrophilic nature of the surface allowing sufficient homogeneous cell attachment and the formation of filamentous F-actin in the cells, allowing osteogenic differentiation. Of all materials tested, PCL 7 (70 wt % PCL, 30 wt % PLGA) demonstrated the greatest chondrogenic differentiation potential under basal and stimulated conditions at both the mRNA and protein production level.