AbstractPolymeric amine (Ia) was prepared by reacting a copolymer ofN‐(2‐hydroxypropyl) methacrylamide (HPMA) andN‐methacryloyl ρ‐aminocaproyl L‐leucinep‐nitrophenyl ester with 1,6‐diaminohexane in excess. The rate of reaction of (Ia) with reactive copolymers of HPMA andp‐nitrophenyl esters of methacryloylated amino acids was investigated. The results indicate that interpenetration of polymeric coils occurs in dimethylsulfoxide solution! .A study of the stability of cross‐links towards chymotrypsinin vitroshowed that in addition to steric factors, subsite interactions between substrate and chymotrypsin must also be borne in mind. An aimed synthesis of crosslinks allowing such interactions leads to an increase in the enzymatic degradability of th