INTEGRATION OF SURFACE MODIFICATION AND 3D FABRICATION TECHNIQUES TO PREPARE PATTERNED POLY(L-LACTIDE) SUBSTRATES ALLOWING REGIONALLY SELECTIVE CELL-ADHESION

Regeneration of organizationally complex tissue requires regulation of spatial distributions of particular cell types in three dimensions. L n this paper we demonstrate an integration of polymer processing and s elective polymer surface modification using methods suitable for const ruction of three-dimensional polymer scaffolds which may aid such cell organization. Specifically, the surfaces of degradable polyesters wer e modified with poly(ethylene-oxide) (PEO)-poly(propylene-oxide) (PPO) copolymers using a process compatible with a solid free-form fabricat ion technique, the 3Dp(TM) printing process. We demonstrate inhibition of cell (hepatocyte and fibroblast) adhesion to regions of two-dimens ional poly(lactide) (PLA) substrates modified with PEO-PPO-PEO copolym ers. We further show that PEO-PPO-PEO-modified surfaces which are not adhesive for hepatocytes or fibroblasts can be made selectively adhesi ve for hepatocytes by covalent linkage of a carbohydrate ligand specif ic for the hepatocyte asialoglycoprotein receptor to the PEO chain end s. Our approach may be generally useful for creating regionally select ive, microarchitectured scaffolds fabricated from biodegradable polyme rs, for spatial organization of diverse cell types.