An alternating copolymer comprising a backbone of residues of a maleic anhydride derivative and those of a compound containing vinylic unsaturation, which also comprises residues of an active compound containing a nucleophilic group, bound to the backbone by a residue of the nucleophilic group, including such a copolymer comprising residues of an active compound containing an alcohol, thiol or amine group. The chemical and biological properties of actives, such as protease inhibitors, neurotransmitter drugs, and other small molecule active drugs, are enhanced, and new applications enabled. Also, artefacts, including a solid medical implant device, dressing or scaffold or a fluid adhesive or medicinal composition comprising such a polymer, and a method of use of such a polymer, including a method for the treatment or prophylaxis of wounds.