Characterization and Enhancement of Local Drug Delivery in Orthopaedic Infection
Abstract
The delivery of antibiotics is an important component of therapy for orthopedic device-related infections (ODRI). In this study, we have investigated new techniques to characterize and enhance antibiotic delivery for ODRI. Characterization of small-molecule diffusion is essential to the development of drug-delivery systems. We have developed a quantitative, non-invasive, longitudinal, micro-CT technique to quantify the diffusion of small-molecules in an intact phantom. We employed a radio-opaque molecule (i.e., Iohexol) as a surrogate for commonly used antibiotics (e.g., Vancomycin). We characterized diffusion from a finite-core carrier into an agar, tissue-equivalent phantom. The estimate of the diffusion coefficient was derived from the analysis of radial diffusion distance of Iohexol and the cumulative release amount of this drug surrogate. This micro-CT method enabled us to describe the elution of small-molecules from enhanced carriers within a porous metal scaffold. To enhance antibiotic delivery, we designed and fabricated gyroid-based scaffolds with appropriate mechanical properties and filled with Iohexol-loaded carriers. Diffusion characteristics within the porous structures were evaluated using the micro-CT technique.