Preparation of Intelligent Chitosan- Collagen Based Scaffolds for Drug Delivery

Chitosan-collagen scaffolds were produced by freeze-drying method and coated with a thermoresponsive polymer poly(N, N-diethylacrylamide) (PDEAAm) to confer them temperature sensitivity using a non residue technology, the supercritical carbon dioxide (scCO2). All native and coated scaffolds were characterized by SEM, intrusion mercury porosimetry, swelling, biodegradability and mechanical analysis. Microarchitectural analysis by scanning electron microscopy and mercury intrusion porosimetry demonstrated that the coating of the pores inner structure could be efficiently achieved without a considerable loss of porosity. Collagen scaffolds lead to larger porous while chitosan scaffolds originated smaller ones. Collagen scaffolds also showed to be more biodegradable with higher swell capacity than chitosan, however chitosan scaffolds are more stiffness than collagen scaffolds. Scaffolds from mixtures of chitosan and collagen showed intermediate properties between chitosan and collagen appearing as a promising option as a biomedical device. Different release profiles of BSA and ibuprofen were achieved from different native and coated scaffolds. The maximum amount of BSA and ibuprofen were 250 and 180 mg/g scaffold, respectively, from collagen scaffolds.