the present invention relates to a polymer obtained from the polymerization of : at least one monomer of formula co — k wherein : k represents o — z or nh — z , z representing m - ch 3 , m - h , m - ch 3 , m - nr 4 r 5 with m representing an integer from 1 to 30 ; r 1 , r 2 , r 3 , r 4 and r 5 independently represent h or a c1 - c6 alkyl ; at least between 0 . 1 and 50 % mol , advantageously between 1 and 30 % mol , more advantageously between 1 and 20 mol % of a cyclic monomer having a exomethylene group of formula wherein : r6 , r7 , r8 and r9 represent independently h or a c5 - c7 aryl group or r6 and r9 are absent and r7 and r8 form together with the carbon atom on which they are bonded a c5 - c7 aryl group ; i and j represent independently an integer chosen between 0 and 2 ; x represents either o or x is not present and in this latter case , cr6r7 and cr8r9 are linked via a single bond c — c and at least one bio - resorbable block copolymer cross - linker .