Copolymers of Hydroxyethyl Methacrylate with Quadrol Methacrylate and with Various Aminoalkyl Methacrylamides as Fibroblast Cell Substrata

Universal application of hydrophilic hydrogels like poly(hydroxy ethyl methacrylate) [p(HEMA)], as biomaterials is limited due to their inabil ity to favorably affect eukaryotic cell growth. In an attempt to favorably manipulate surface properties, a series of HEMA copolymers was made with 10-40% aminoethyl methacrylamide (AEMA), aminopropyl methacrylamide (APMA), Quadrol methacrylate (QM), N,N'-bis(2-hydroxypropyl)aminoethyl meth acrylamide (HPAEMA) or dimethylaminoethyl methacrylate (DMAEMA). Balb/c 3T3 fibroblast cell growth was observed on HEMA:AEMA (80:20), HEMA:QM (80:20) and HEMA:HPAEMA (90:10) copolymers. Cell growth on HEMA: AEMA (80:20) was comparable to HEMA:DMAEMA (60:40). HEMA copolymers containing APMA, a homolog of AEMA, exhibited cytotoxicity. Cationic groups of primary and tertiary amines present in the HEMA copoly mer hydrogels favorably contribute to the support of cell growth. The effect of hydroxyl groups on cell growth appears to be favorable. The extent of cell growth varied with the concentration of the cationic groups in the hydrogel. The cytotoxicity of the HEMA:APMA copolymers as compared with the bio compatibility of the HEMA:AEMA copolymers suggests that the length of the branch from the polymer chain for copolymers with primary amino groups may be a critical factor in biocompatibility.