|Hee-Cheol Kim1, Jens Träger1, and Norbert Hampp1,2
1Faculty of Chemistry, University of Marburg, Hans-Meerwein-Straße, 35032 Marburg, Germany
2Material Science Center Marburg, D-35032 Marburg, Germany
Intraocular lens (IOL) implantation is the standard technique to treat cataract. But despite recent progress in surgical procedures, posterior capsule opacification (PCO) is still the most frequent postoperative complication of IOL implantation. We present a novel drug delivery device to prevent PCO which is caused by the regeneration and extracellular matrix production of the residual lens epithelial cells. A drug delivery polymer suitable for manufacturing IOLs has been developed. The therapeutic agents are attached through a UV light sensitive cyclobutane-type linker to the acrylic polymer backbone which is responsible for the optical performance of the IOL. UV-photons in daylight conditions, however, cannot affect the drug delivery device, due to the high absorption of the cornea at this spectral region. The controlled drug release is accomplished by two-photon absorption induced cleavages of the linker structure. Since the two-photon absorption requires high photon densities, this does not occur in any lighting conditions in daily life, but is easily achieved by focused laser beams with an excellent spatial selectivity. In this proof-of-principle study we have investigated the properties of the therapeutic system with approved drugs, 5-fluorouracil and chlorambucil. The drug delivery was successfully demonstrated in vitro and additional cell tests confirmed that the device itself shows no cytotoxicity until photochemical stimulation. This concept introduced here can provide a powerful tool for designing controlled drug delivery devices in ophthalmology.