The present invention relates to a macromolecule-loaded bioresorbable crosslinked polymer wherein the polymer is obtainable from the polymerization of: (i) at least one monomer of formula (I) (CH2=CR1)CO-K wherein: -K represents O-Z or NH-Z, Z representing (CR2R3)m-CH3, (CH2-CH2-O)m-H, (CH2-CH2-O)m-CH3, (CH2)m-NR4R5 with m representing an integer from 1 to 30; -R1, R2, R3, R4 and R5 independently represent H or a C1-C6 alkyl; and (ii) at least one bio-resorbable block copolymer cross-linker, and wherein the macromolecule is chosen in the group consisting of proteins and nucleic acids.