Synthesis of poly[alpha,beta-(N-2-hydroxyethyl-DL-aspartamide)]-thioglycolic acid (PHEA-TGA) conjugate as a new polyaspartamide thiomer is described. The parent polymer PHEA is chemically modified by introducing sulphydryl-bearing compound thioglycolic acid. By varying the reaction conditions several batches of PHEA-TGA conjugates were prepared and analyzed. Tensile studies revealed that total work of adhesion of PHEA-TGA increased more than twice compared to the unmodified polymer. Microparticles prepared from the thiolated polymer preserved its bioadhesive properties. (C) 2004 Elsevier B.V. All rights reserved.