Sustained intrascleral drug delivery using hollow microneedles to target posterior segment eye diseases

A 3D-printed adapter guided injections and the distribution of different formulations was studied using microscopy and optical coherence tomography. To address the need for long-acting treatments, developed a thermoresponsive hydrogel by chitosan conjugated poly (N-isopropyl acrylamide) for controlled release of sunitinib (SUN), an anti-angiogenic drug. To reduce burst release, SUN-loaded PLGA nanoparticles were incorporated into the hydrogels, achieving sustained release over 3 months.

In vitro and ex vivo studies demonstrated the safety and anti-angiogenic efficacy of the formulations. In vivo studies in rabbits showed significantly higher scleral drug retention with the nanoparticle-loaded hydrogels compared to SUN solution or hydrogel alone. This thesis demonstrates the potential of HMNs for minimally invasive intrascleral drug delivery and the promise of nanoparticle-loaded thermoresponsive hydrogels for long-term management of AMD and other chronic ocular diseases.<br><br><i>Thesis is embargoed until 31 December 2027</i>.<br><br>