Surface Characteristics and Fibroblast Adhesion Behavior of RGD-Immobilized Biodegradable PLLA Films

摘要

The interactions between the surface of scaffolds and specific cells play an important role in tissue engineering applications.Some cell adhesive ligand peptides including Arg-Gly-Asp (RGD) have been grafted into polymeric scaffolds to improve specific cell attachment.In order to make cell adhesive scaffolds for tissue regeneration,biodegradable nonporous poly(L-lactic acid) (PLLA) films were prepared by using a solvent casting technique with chloroform.The hydrophobic PLLA films were surface-modified by Argon plasma treatment and in situ direct acrylic acid (AA) grafting to get hydrophilic PLLA-g-PAA.The obtained carboxylic groups of PLLA-g-PAA were coupled with the amine groups of Gly-Arg-Asp-Gly (GRDG,control) and GRGD as a ligand peptide to get PLLA-g-GRDG and PLLA-g-GRGD,respectively.The surface properties of the modified PLLA films were examined by various surface analyses.The surface structures of the PLLA films were confirmed by ATR-FTIR and ESCA,whereas the immobilized amounts of the ligand peptides were 138-145 pmol/cm~2.The PLLA surfaces were more hydrophilic after AA and/or RGD grafting but their surface morphologies showed still relatively smoothness.Fibroblast adhesion to the PLLA surfaces was improved in the order of PLLA control < PLLA-g-PAA=PLLA-g-GRDG < PLLA-g-GRGD,indicating that PLLA-g-GRGD has the highest cell adhesive property.