Sustained, local delivery of the antibiotic ciprofloxacin under different formats from porous silk protein-based memory foam systems was studied. Similarly, protease XIV was incorporated during processing to provide control of the degradation kinetics of the silk materials. In vitro antibiotic release studies combined with degradation assessments were utilized to assess the mechanisms and kinetics of release from the silk materials. The sequestered protease XIV affected the degradation profiles of the silk foams yet did not impact the release kinetics of the ciprofloxacin, which was controlled by solubility and diffusion of the drug. The ability to tune the release of ciprofloxacin between 1 and 200 days, combined with the option to modulate the degradation rate up to 80% in 2 weeks via incorporation of a protease, suggests utility for drug release devices. Further, we anticipate that this approach could also be extended to other medical implant needs and other drugs.
Keywords: antibiotic; biomaterials; controlled release; degradable; memory foam; silk.