Hydrophilic polymethacrylates containing cholic acid-ethylene glycol derivatives as pendant groups

In an effort to improve the hydrophilicity of bile acid containing polymers , we have synthesized new methacrylate monomers by incorporating ethylene g lycol and oligo(ethylene glycol) spacers of different lengths between choli c acid and methacrylate residues. The monomers were subsequently polymerize d by free radical reaction in solution. The methyl ester protecting groups on the cholic acid residue were selectivity hydrolyzed to restore the carbo xylic acid group of cholic acid. Water absorption tests showed that the hyd rophilicity of the polymers was improved with increasing length of oligo(et hylene glycol) spacers and upon restoration of the carboxylic acid group of the cholic acid residue.