(425e) Analysis of Therapeutic Drug Release from Additively Manufacturable Materials As Affected By Mechanical Stress and Strain

The release profile of a model therapeutic agent from a drug eluting biodegradable and additively manufacturable polymer was assessed under cyclic mechanical loading. Therapeutic agents within implanted medical components can serve a wide variety of useful purposes from enhancing the performance of artificial joints to preventing thrombosis around a stint. However, little data exists at this time on the effect a repetitive mechanical loading may have on the release profile of the therapeutic agent. While a stint may be regularly loaded at frequencies similar to 1 Hz, other medical components, such as artificial joints, may experience completely different mechanical environments with irregular, largely spaced loadings. Such wide differences in environment highlight the need to understand the possible effects mechanical loadings can have on the release from these components. This work is intended to provide a more complete understanding of these materials by collecting release profile data, under a variety of mechanical conditions, for an SLA printable poly(ethylene glycol) diacrylate-based biodegradable material containing aspirin as a model therapeutic. Cyclic loads, of frequencies from 0.1 to 2.0 Hz and strains from 1 to 5 % over the course of 240 hours, were applied while the sample was submersed in a phosphate buffer. Samples of dissolution media were extracted, and their aspirin content determined, 4 times every 24 hours to track release rates while DMA frequency sweeps were performed in the same intervals to track the material’s degradation rate. The results serve to quantify the role of mechanical loading upon the release profiles from these materials, as well as the interaction between these properties and the decomposition of the sample.