Concanavalin a Microspheres for a Self‐Regulating Insulin Delivery System

Abstract

AbstractA self‐regulating insulin delivery system based on the competitive binding of glucose and p‐succinylamidophenyl‐α‐D‐glycopyranoside‐insulin (SAPG‐insulin) to crosslinked concanavalin A (Con A) microspheres (MSs) has been investigated. Con A MSs prepared by a water‐in‐oil emulsion technique demonstrated properties of binding to glucose and SAPG‐insulin (binding constants of 1.25 × 103 and 1.28 × 104 M−1. respectively) that are similar to the literature values of these properties for unmodified Con A. The retained binding capacity (number of binding sites per molecule) of Con A MSs, produced with 20% of the εeamino groups crosslinked, was ∼28% that of intact Con A. As a new device, Con A MSs loaded with SAPG‐insulin was enclosed in a heat‐sealed, surface‐modified, porous poly(vinylidene difluoride) membrane pouch. This system showed a pulsatile release pattern for insulin with a short lag time in response to glucose challenges of 50‐500 mg/dL. The pattern of release of SAPG‐insulin from the devices was studied with varying design parameters, such as surface area, membrane pore size, and loading content of SAPG‐insulin.