a highly porous three - dimensional biodegradable poly matrix with hydrolytically unstable side chains is prepared and used as a scaffold for the growth of osteoblast cells . in a preferred embodiment , the poly includes between 10 and 90 % hydrolytically unstable side chains including glucosyl , glyceryl , glyceryl , imidazolyl or ethoxy units , for example , poly phosphazene ]. the addition of the glucosyl , glycinyl or glyceryl side chains to the polymer can also be used generally to enhance growth rates of cells adhered to the polymer , presumably through uptake and metabolism of the simple sugar or alcohol units .