| abstract |
Disclosed is a biocompatible membrane comprising a hydrophilic polyurea composition. The hydrophilic polyurea composition comprises the product of a reaction mixture comprising (a) an amino terminated polysiloxane, (b) a hydrophilic polymer selected from the group consisting of a diamino terminated copolymer of polypropylene glycol and polyethylene glycol, polyethylene glycol, polypropylene glycol and diamino polyethylene glycol having an average molecular weight of from about 400 to about 2000, and (c) diisocyanate selected from the group consisting of hexamethylene-1,6-diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, and isophorone diisocyanate, and constituting about 50 mole % of the reaction mixture. In this mixture, (a) and (b) constitute a polymeric portion of the reaction mixture, and the hydrophilic polyurea composition has a ratio of its diffusion coefficient for oxygen to its diffusion coefficient for glucose of from about 2,000 to about 10,000. Also provided are biosensors coated with a membrane of the invention, and methods of using such biosensors to measure an analyte in a tissue of a subject. |