Gel compositions prepared from crosslinkable polysaccharides, polycations and/or lipids and uses therefor

A biocompatible gel containing entrapped mammalian cells produced by:

• a) chemically modifying a biocompatible material having a reactive functionality thereon with a reactive species capable of free radical polymerization to form a modified biocompatible material having the formula:
• A--X
• wherein
• A is a polysaccharide, polycation or lipid;
• X is a moiety containing a carbon-carbon double bond or triple bond capable of free radical polymerization, wherein X is not a methylol amide;
• and
• A and X are linked covalently through linkages selected from the group consisting of ester, ether, thioether, disulfide, amide, secondary amines, tertiary amines, direct C--C linkages, sulfate esters, sulfonate esters, phosphate esters, urethanes, and carbonates;
• and
• b) contacting said modified biocompatible material with a free radical initiating system under free radical producing conditions in an aqueous media that contains mammalian cells and is free of organic solvents, wherein said free radical producing conditions are not detrimental to the viability of said mammalian cells.