Three-dimensional-printed Refillable Drug Delivery Device for Long-term Sustained Drug Delivery to Retina

As the aging population increases worldwide, the number of patients with retinal diseases requiring long-term treatment, such as for age-related macular degeneration (AMD), is expected to increase. Intravitreal injection is the most common clinical treatment method for AMD, but a less invasive method and continuous drug administration are desirable. Here, we report a 3D-printed refillable drug delivery system (DDS) that fits the curvature of the eyeball. This DDS has three parts: a drug injection port for drug reloading, a drug release port with an opening for unidirectional release into the sclera, and a drug tank for drug retention. We evaluated in vitro the sustained release of fluorescein isothiocyanate conjugate (FITC)-albumin used as a model drug from 20 wt% poly(vinyl alcohol) (PVA) hydrogel placed at the release port over 200 days. Furthermore, we showed that ten successive drug refills could be carried out without problems. Finally, a smaller version of the DDS was implanted in vivo in rabbit sclera, which showed sufficient fluorescence release in the retina and the choroid/RPE homogenate. The present DDS with drug reloading capacity shows excellent promise as a minimally invasive drug administration tool for the long-term treatment of retinal diseases.

Automated summary

With the increasing global aging population, the number of patients with retinal diseases requiring long-term treatment is expected to rise. Researchers have developed a 3D-printed refillable drug delivery system (DDS) that fits the curvature of the eyeball, providing a less invasive and continuous drug administration method. In laboratory tests, the DDS demonstrated sustained release of a model drug over 200 days and was able to undergo ten successive drug refills without any issues. In vivo experiments in rabbit sclera also showed promising results, indicating the potential of this DDS for long-term treatment of retinal diseases.