and

312 ABSTRACT: A novel polymer system sensitive to glucose concentration has been studied as a can-didate material for chemically regulated insulin release system. Phenylboronic acid is able to form reversible binding to cis-diol substances. A glucose responsive insulin release system has been studied with utilization of phenylboronic acid polymers for the key material in the exchange reaction between gluconic acid modified insulin (G-Ins) and glucose. The released concentration of G-Ins from the polymer was pulsatile in response to the repeated stepwise concentration changes of glu-cose. The linearity between glucose concentration and peak height of released G-Ins and the release response demonstrated no lag time to changes in glucose concentration were other important finites. The phenylboronic acid polymer shows considerable promise for use in a self-regulating insulin delivery system