Attachment and Growth of Fibroblasts on Poly(L-lactide/∊-caprolactone) Scaffolds Prepared in Supercritical CO 2 and Modified by Polyethylene Imine Grafting with Ethylene Diamine-Plasma in a Glow-Discharge Apparatus

Abstract

In this study, a copolymer of L-lactide and ∊-caprolactone (M_n: 73,523, M_w: 127,990 and PI: 1.74) was synthesized by ring-opening polymerization by using stannous octoate as the catalyst. FTIR, ¹H-NMR and DSC confirmed the copolymer formation. The copolymer films were prepared and a novel method was developed to produce highly porous sponges for potential use in tissue engineering. Films were subjected to supercritical CO₂ at 3300 psi and 70°C to create porous structures for production of possible tissue engineering scaffolds. The pore sizes were in the range of 40–80 mm. The copolymer films were pre-wetted with polyethylene imine (PEI) and then treated with ethylene diamine (EDA)-plasma in glow-discharge apparatus. Gas plasma surface modification of three-dimensional scaffolds fabricated by supercritical carbon dioxide technique was demonstrated to enhance cell adhesion, proliferation, and differentiation over 6 days in culture using L929 fibroblast cell line. Alkaline phosphatase (ALP) activity and glucose uptake in cell culture medium were followed in the cell culture experiments. Fibroblastic cell attachment and growth on the EDA-plasma treated scaffolds were rather low. However, both cell attachment and growth were significantly increased by PEI pre-treatment before EDA-plasma. The changes in ALP activity and glucose uptake also supported the cell growth behavior on these PEI and EDA-plasma treated scaffolds.