Degradable hydrogels for tissue engineering - Part II: Responses of fibroblasts and macrophages to linear PHEMA

A series of linear poly(2-hydroxyethyl methacrylate) (PHEMA) with defined molecular weights (MW) and narrow molecular distributions were synthesized by reversible additionfragmentation chain transfer (RAFT) polymerization using cumyl dithiobenzoate (CDB) as a chain transfer agent. Murine fibroblasts (3T3) were exposed to eluates from various PHEMA samples, washed or unwashed, and with or without dithioester end groups. After 72 hrs in cell culture, no cytotoxic response was elicited by the polymer samples devoid of dithioester end groups, and which also underwent a thorough washing regime. Specimens throughout the entire MW range were internalized by a macrophage (cell line Raw 264), suggesting that such polymers can be used as models for studying the biodegradation of PHEMA