Stereolithography 3D printed implants: a preliminary investigation as potential local drug delivery systems to the ear

The current study is a preliminary investigation on the use of stereolithography 3D printing technology in the field of personalized medicines and specifically for delivering drugs locally, which can for example usefully be applied to ear infections. The main aim is the development of drug-loaded implants for the treatment of ear diseases, to improve patient compliance and to overcome the limitations of current delivery approaches. Multiple prototypes of implant geometries have been created and printed using a flexible resin containing 0.5% w/v of Levofloxacin. Physicochemical characterization of the printed implants was carried out using a variety of techniques (e.g., microscopic, spectroscopic, and mechanical analysis). Finally, preliminary in vitro tests were performed to evaluate the release profile of Levofloxacin, the prototype implant's stability, and their antimicrobial property. The results obtained show that there is no interaction between the resin and the drug, which is perfectly solubilized in the device. In addition, the results of the mechanical tests show that the material used resists compression without compromising the design itself, and the diffusion test has shown that the drug diffused through the matrix prototype at 50% over 3 weeks. The selected designs showed higher antimicrobial activity on E.coli than on S.aureus.