ii) at least one monomer or {HEAD ~ macromer} containing at least one free radical polymerizable group, wherein at least one of the monomers or macromers includes {TAIL ~ an anhydride linkage} 
ii ) at least one monomer or { HEAD ~ macromer } containing at least one free radical polymerizable group , wherein at least one of the monomers or macromers includes { TAIL ~ an anhydride linkage }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL