Development of new hydroactive dressings based on chitosan membranes: characterization and in vivo behavior

DE QUEIROZ,A.A.A.; FERRAZ, H.G.; ABRAHAM,G.A.; FERNANDEZ,M.M.; LOPEZ BRAVO,A.; SAN ROMAN,J

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH

John Wiley & Sons, Inc.

Lugar: New York, USA.; Año: 2003 vol. 64A p. 147 - 154

0021-9304

In this work our attention has been focused on employing biopolymers to compose hydrogels with pseudocrosslinks caused by interactions of hydrophobic side chains and hydrogen bonding, which stabilize hydrogel-forming molecules.  Different poly(vinyl alcohol) (PVA) / chitosan lactate (ChL)-blended hydrogels containing nitrofurazone as a local anti-infective drug were prepared by the phase inversion technique. The swelling degree, surface free energy, mechanical properties and nitrofurazone release of these membranes were determined. Blood compatibility of these systems was evaluated by the open-static platelet adhesion test with whole human blood. The results shows that absorption into the PVA/ChL membranes slows down, governed by the rate at which the dressing interacts with the physiological fluid, being the swelling degree values up to 200%. The rate of release of nitrofurazone seems to depend on the ChL percentage on the blend as well as the pH of the solution. The surface free energy values were in the range 20-30 dynes/cm which result appropriate for a favorable interaction with blood. From the Young’s module curve it can be seen that elastic hydrogels were obtained with increment of ChL in the PVA/ChL blends. Values of platelet adhesion and whole blood clotting times for the PVA/ChL blends as well as the increase of ChL, which appears to reduce the fibrinogen adsorption on the PVA/ChL membranes, demonstrate that the blood compatibility of PVP/ChL blends is superior to that separated polymers. The results of in vivo experiments in rats were in very good agreement with these observations suggesting that PVA/ChL may serve as a new type of potential wound dressing material.