The impact of lutein-loaded poly(lactic-co-glycolic acid) nanoparticles following topical application: An in vitro and in vivo study.

Antioxidant therapies are of interest in the prevention and management of ocular disorders such as cataracts. Although an active area of interest, topical therapy with antioxidants for the treatment of cataracts is complicated by multiple ocular anatomical barriers, product stability, and solubility. Entrapment and delivery of antioxidants with poly(lactic-co-glycolic acid) nanoparticles is a possible solution to these challenges, however, little is known regarding their effects in vitro or in vivo. Our first aim was to investigate the impact of blank and lutein loaded PLGA nanoparticles on viability and development of reactive oxygen species in lens epithelial cells in vitro. Photo-oxidative stress was induced by ultraviolet light exposure with cell viability and reactive oxygen species monitored. Next, an in vivo, selenite model was utilized to induce cataract formation in rodents. Eyes were treated topically with both free lutein and lutein loaded nanoparticles (LNP) at varying concentrations. Eyes were monitored for the development of anterior segment changes and cataract formation. The ability of nanodelivered lutein to reach the anterior segment of the eye was evaluated by liquid chromatography coupled to mass spectrometry of aqueous humor samples and liquid chromatography coupled to tandem mass spectrometry (targeted LC-MS/MS) of lenses. LNP had a minimal impact on the viability of lens epithelial cells during the short exposure timeframe (24 h) and at concentrations < 0.2 µg LNP/µl. A significant reduction in the development of reactive oxygen species was also noted. Animals treated with LNPs at an equivalent lutein concentration of 1,278 µg /mL showed the greatest reduction in cataract scores. Lutein delivery to the anterior segment was confirmed through evaluation of aqueous humor and lens sample evaluation. Topical treatment was not associated with the development of secondary keratitis or anterior uveitis when applied once daily for one week. LNPs may be an effective in the treatment of cataracts.

Modulation of Methoxyfenozide Release from Lignin Nanoparticles Made of Lignin Grafted with PCL by ROP and Acylation Grafting Methods.

An efficient and sustainable agriculture calls for the development of novel agrochemical delivery systems able to release agrochemicals in a controlled manner. This study investigated the controlled release of the insecticide methoxyfenozide (MFZ) from lignin (LN) nanoparticles (LNPs). LN-grafted poly(ε-caprolactone) (LN-g-PCL) polymers were synthesized using two grafting methods, ring-opening polymerization (ROP)(LN-g-PCLp) and acylation reaction (LN-g-PCLa), creating polymers capable of self-assembling into nanoparticles of different properties, without surfactants. The LN-g-PCLp polymers exhibited a degree of polymerization (DP) from 22 to 101, demonstrating enhanced thermal stability after LN incorporation. LNPs loaded with MFZ exhibited a spherical core-shell structure with a hydrophilic LN outer layer and hydrophobic PCL core, with sizes affected by grafting methods and DP. LNPs controlled MFZ release, displaying variation in release profiles depending on the grafting methodology used, LN-g-PCLp DP, and temperature variations (23 to 30 °C). LNPs formulated with LN-g-PCLa showed a cumulative release of MFZ of 36.78 ± 1.23% over 196 h. Comparatively, increasing the DP of the LN-g-PCLp polymers, a reduction of the LNPs release rate from 92.39 ± 1.46% to 70.59 ± 2.40% was achieved within the same time frame. These findings contribute to identifying ways to modulate the controlled release of agrochemicals by incorporating them in renewable-based LNPs.