Photodynamic Ocular Drug Delivery System with Optical Coherence Tomography Oriented Microscale Robots

Retinal diseases are the most common reasons of the irreversible blindness worldwide.

Common retinal diseases, such as diabetic retinopathy, macular degeneration, retinal vein occlusion and non-infectious uveitis, mostly require intravitreal steroid injections in clinical management.

Unfortunately, the intravitreal steroid injections, leads other important ocular problems, such as elevation of intraocular pressure, intravitreal infections and progression of cataracts. Because of these reasons, targeted drug delivery systems are necessity for the medical treatment of retinal diseases.

PHOTodynamic Ocular Drug delivery system with Optical Coherence Tomography Oriented microscale Robots (PHOTODOCTOR) project combines three novel technologies to solve this important clinical problem.

The first technological advancement for the project is dexamethasone saturated hyaluronic acid (HA) hydrogels with organo-ruthenium complexes, which enables controllable degradation under visible light exposure. With the help of visible light controlled degradation, dexamethasone will be released with the light pulses.

Then the hydrogels will be supplemented with super paramagnetic iron oxide nanoparticles (SPIONs) and 3D printed as helical micro-swimmers. Insertion of the SPIONs will help the magnetic actuation of the hydrogel-based microrobots in the intraocular space.

Lastly, SPIONs supplemented HA hydrogels will be observed with high resolution optical coherence tomography (OCT) system in the intraocular space to guide them in diseased area of the retina.

While HA based structure increases penetration in vitreous and helps to the attachment on the retina, SPIONs will increase the visibility of the microrobots in OCT imaging.

By this way, magnetic driven, visible light triggered intraocular drug release system with the OCT guidance will be produced and it could be used for not only intravitreal steroid delivery but also treatment of retinal tumors and other retinal problems.