Structured drug-loaded bioresorbable films for support structures
Journal of Biomaterials Science. Polymer Edition
Bioresorbable lms can serve simultaneously as anatomic support structures and as drug delivery platforms. In the present study, bioresorbable PLLA lms containing dexamethasone were developed through solution processing. The effect of processing parameters on the lm morphology and the resulting mechanical properties was studied. A model describing the structuring of these lms is suggested. Generally, the solvent evaporation rate determines the kinetics of drug and polymer crystallizationand
... tallizationand thus, both the mode of drug dispersion in the polymer and the resulting mechanical properties. Two types of structured lms were studied: (1) a polymer lm with drug located on its surface, obtained due to drug skin formation accompanied by a later polymer core formation; and (2) a polymer lm with small drug particles and crystals distributed within the bulk, obtained by parallel solidi cation of the two components. A prototypical application of these lms is an expandable biodegradable support structure (stent), which we have developed. This stent demonstrated good initial mechanical properties. The lm structure has only a minor effect on the stent radial compression strength, but more signi cantly affects the tensile mechanical properties.