Osteoblast function on synthetic biodegradable polymers

TLDR

Rat osteoblasts were cultured on films of biodegradable PLLA, 75:25 PLGA, 50:50 PLGA, and PGA for up to 14 days. Osteoblasts attached equally to all polymers, proliferated to confluence by day 4 with plateau by day 7, and showed increased alkaline phosphatase activity only on 75:25 PLGA (comparable to TCPS), while collagen synthesis, morphology, and activity on PLLA, 50:50 PLGA, and PGA remained unchanged, indicating poly(alpha‑hydroxy esters) are suitable substrates for osteoblast culture and bone regeneration.

Abstract

Rat osteoblasts were cultured on films of biodegradable poly(L-lactic acid) (PLLA), 75:25 poly(DL-lactic-co-glycolic acid) (PLGA), 50:50 PLGA, and poly(glycolic acid) (PGA) for up to 14 days. Osteoblasts attached equally well to all the polymer substrates after 8 h in culture. By day 4 in culture, osteoblasts had exceeded confluency numbers, and their proliferation leveled off by day 7. An increase in alkaline phosphatase (ALP) activity from 1.92 (+/- 0.47) x 10(-7) for day 7 to 5.75 (+/- 0.12) x 10(-7) mumol/cell per min for day 14 was reported for osteoblasts cultured on 75:25 PLGA, which was comparable to that observed for tissue culture polystyrene (TCPS) controls. The ALP activities expressed by osteoblasts cultured on PLLA, 50:50 PLGA, and PGA films did not significantly increase over time. Collagen synthesis for osteoblasts cultured on all polymer substrates was similar to that of TCPS and did not vary with time. The morphology of cultured osteoblasts was not affected by the continuous degradation of the polymer substrates. These results demonstrate that poly(alpha-hydroxy esters) can provide a suitable substrate for osteoblast culture and hold promise in bone regeneration by osteoblast transplantation.