The effect of polymeric chemistry on the expression of bone-related mRNAs and proteins by human bone-derived cells in vitro

This study used human bone-derived cells (HBDC) grown on two defined polyme ric substrata to examine the effect of substrata chemistry on the expressio n of mRNAs and proteins characteristic of the osteoblastic phenotype. The g rowth profile of cells grown on tissue culture: polystyrene (TCP) was expon ential whereas for those seeded on polyethylenelerephthalate (PET) there wa s a pronounced lag period before cellular multiplication. The temporal expr ession pattern of mRNAs in HBDC cultured on TCP was similar to that of cell s on PET. On TCP, the levels of several mRNAs peaked at day 4, as cellular proliferation slowed. In contrast, the induction in mRNA levels in cells gr own on PET corresponded to maximum mitotic activity. There appears to be se quential cascade in protein expression in cells grown on TCP with overlappi ng peaks of thrombospondin (Tsp), osteocalcin (OC) and osteopontin (OP) exp ression. In contrast, peak intracellular protein expression levers for Tsp, OC and OP did not overlap when cells were grown on PET.