Abstract
Purpose :
Appropriate care of ocular injuries is vital to the preservation of vision. Full-thickness injuries are especially challenging in low-resource or emergency settings as current standards of care involve high surgical skill, equipment, and complex drug regimens. Nanoparticle (NP) based drug delivery systems (DDS) allow for localized tissue targeting with controlled drug release and dosages. Many anti-inflammatory ophthalmic drugs are class II compounds with low bioavailability due to their hydrophobic nature. Herein, we demonstrate a novel DDS by loading drug-laden micelles into a visible light photopolymerizable hydrogel patch with the potential to seal ocular injuries and elute a hydrophobic anti-inflammatory drug.
Methods :
Micelle building blocks were synthesized via radical polymerization to create polyethyleneglycol-b-(N-(2-hydroxypropyl) methacrylamide-co-oligolactate (PEG-b-(pHPMAm-co-Lacn)). Micelle characterization utilized gel permeation chromatography (GPC) to obtain the polydispersity index (PDI), and proton nuclear magnetic resonance (1HNMR) to measure molecular weight (Mw). Micelle physicochemical properties were obtained with dynamic light scattering (DLS) and zetasizer analysis. Loteprednol Etabonate (LE) was encapsulated into micelles and loading efficiency and in vitro drug release were measured using high performance liquid chromatography (HPLC). Lastly, LE loaded micelles were incorporated into the patch composed of methacrylated biopolymers with varying concentrations.
Results :
Synthesized micelle characterization showed a block co-polymer with Mw of ~20 kDa and a PDI of 1.46. LE was successfully loaded into micelles with a size of 100-120 nm and loading efficiency of ~ 30%. Micelles were stable for up to five days of incubation in buffer solution at 37°C. A first order (sustained) release of LE was demonstrated for 10 days, with 98% drug released on day 10. Micelles loaded into the patch showed complete and sustained release of LE within 10 days. DLS analysis of release media showed retention of micelles within the hydrogel network.
Conclusions :
The adhesive patch successfully loads a hydrophobic drug and allows for sustained release for up to 10 days. Our NP DDS can address critical factors in ocular injury care by its potential use in ocular injury sealing and drug delivery which can increase drug bioavailability without need for complicated and high frequency drug regimen.
This is a 2021 ARVO Annual Meeting abstract.