Designed rubbery biomaterials

Research on novel implantable rubbery polyisobutylene-based biomaterials ca rried out at the University of Akron during the past similar to 15 years is outlined. Specific attention is paid to recent investigations focusing on the synthesis of semipermeable amphiphilic networks designed to be used as immunoisolatory membranes. The membranes envelop insulin-producing living p ig beta cells. They are biocompatible to the host (human) and the guest (be ta cells) and remain permeable for many months in vivo. They are rubbery sl ippery, robust, sterilizable, optically transparent, with controlled pore d imensions that allow the in-diffusion of glucose and nutrients, out-diffusi on of insulin and wastes, but they do not allow the entry of immunoproteins (IgG). The pores remain permeable for many months in vivo. The membranes a re made by copolymerizig/crosslinking hydrophilic (meth)acrylates with meth acrylate-telechelic polyisobutylenes. Controlling the molecular weights of the constituent segments controls the pore sizes of the membranes. Immunois olated pig beta cells enveloped in our membranes and implanted subcutaneous ly in a rat have corrected severe hyperglycemia.