Tunable drug release from hydrolytically degradable layer-by-layer thin films.

The development of new thin film fabrication techniques that allow for precise control of degradation and drug release properties could represent an important advance in the fields of drug delivery and biomedicine. Polyelectrolyte layer-by-layer (LBL) thin films can be assembled with nanometer scale control over spatial architecture and morphology, yet very little work has focused on the deconstruction of these ordered thin films for controlled release applications. In this study, hydrolytically degradable LBL thin films are constructed by alternately depositing a degradable poly(beta-amino ester) (polymer 1) and a series of model therapeutic polysaccharides (heparin, low molecular weight heparin, and chondroitin sulfate). These films exhibit pH-dependent, pseudo-first-order degradation and release behavior. The highly versatile and tunable properties of these materials make them exciting candidates for the controlled release of a wide spectrum of therapeutics.