. . . . "Specific examples of suitable degradable materials include polysaccharides such as dextrans or celluloses; chitins; chitosans; liquid esters (e.g., triethyl citrate); proteins (e.g., gelatin); aliphatic polyesters; poly(lactides); poly(glycolides); poly(??-caprolactones); poly(hydroxybutyrates); poly(anhydrides); aliphatic polycarbonates; ortho esters, poly(orthoesters); poly(amino acids); poly(et" .