文摘
Elastin-like polypeptides (ELPs) exhibit an inverse phase transition temperature (Tt) in response to changes in their environment. We hypothesized that processing ELP鈥揷ollagen composites at temperatures higher than the Tt of ELP (32 掳C) will affect their microstructure and subsequently, achieve tunable release of model drugs. The composite coatings were prepared by formation of ELP鈥揷ollagen hydrogels at 37 掳C, incubation at 37, 45, or 55 掳C, and finally air-drying at 37 掳C. Scanning electron micrographs revealed that the fabrication process affected both the collagen and ELP microaggregate phases. A gradual time dependent bovine serum albumin (BSA) release that followed the power law and a burst antibiotic doxycycline release followed by a linear zero-order release were observed. Importantly, BSA and doxycycline releases were dependent on the ELP microaggregate size, which was governed by the processing temperatures. This study lays the foundation to achieve optimized composite microstructures by controlling processing conditions for drug delivery applications.