BLENDS OF SYNTHETIC AND NATURAL POLYMERS AS DRUG-DELIVERY SYSTEMS FORGROWTH-HORMONE

In order to overcome the biological deficiencies of synthetic polymers and to enhance the mechanical characteristics of natural polymers, tw o synthetic polymers, poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) were blended, in different ratios, with two biological polymers , collagen (C) and hyaluronic acid (HA). These blends were used to pre pare films, sponges and hydrogels which were loaded with growth hormon e (GH) to investigate their potential use as drug delivery systems. Th e GH release was monitored in vitro using a specific enzyme-linked imm unosorbent assay. The results show that GH can be released from HA/PAA sponges and from HA/PVA and C/PVA hydrogels. The initial GH concentra tion used for sample loading affected the total quantity of GH release d but not the pattern of release. The rate and quantity of GH released was significantly dependent on the HA or C content of the polymers.