AN INVESTIGATION OF THE GROWTH OF HUMAN DERMAL FIBROBLASTS ON POLY-L-LACTIC ACID IN-VITRO

A tissue engineered implant involving cells seeded on bioresorbable ma terials is an attractive proposition for the repair of soft tissue bec ause in the long term the material is resorbed leading to a natural re pair. The aim of this study was to assess the effect of poly-L-lactic acid (PLA) on the growth of human dermal fibroblasts in vitro. The res ults have been compared to other resorbable materials, polyhydroxybuty rate (PHB), polycaprolactone (PCL) and polyglycolic acid (PGA). Therma nox (Tmx) and tissue culture plastic (Tcp) were used as positive contr ols. PLA compared favourably with the other bioresorbable materials, a s a substrate for fibroblast attachment and proliferation. No evidence of cytotoxicity was observed for cells cultured in polymer extracts. Colonies of adhered fibroblasts were observed on PLA which exhibited n ormal bipolar morphology when viewed using phase contrast microscopy a nd cryo-SEM. Cellular proliferation was measured by tritiated thymidin e incorporation with total DNA as a baseline. Concerns associated with the use of PLA as the bioresorbable material utilized in tissue regen eration are primarily related to the effect of degradation products on the cellular component. No effect on the growth of dermal fibroblasts was observed in the presence of degradation products or lactic acid s tandards (0-1000 mu g/ml/48 h). This study has demonstrated that human dermal fibroblasts proliferated and formed a confluent monolayer on P LA, which may prove to be a suitable scaffold for soft tissue repair s ystems, providing biomechanical and biodegradation requirements can be fulfilled.