Gels for encapsulation of biological materials

Abstract

This application is a continuation of U.S. application Ser. No. 08/783,387, filed Jan. 13, 1997, now U.S. Pat. No. 6,258,870, which is a divisional of U.S. application Ser. No. 08/484,160, filed Jun. 7, 1995, now abandoned, which is a divisional of U.S. application Ser. No. 07/958,870, filed Oct.