Catechin loaded PLGA submicron-sized fibers reduce levels of reactive oxygen species induced by MWCNT in vitro.

Reactive oxygen species (ROS) are common products of normal aerobic cellular metabolism, but high levels of ROS lead to oxidative stress and cellular damage. Therefore, effective antioxidant therapies are needed to prevent ROS overproduction. This study reports the development of poly(l-lactide-co-glycolide) (PLGA) bicomponent fibers loaded with selected amounts of the natural polyphenolic antioxidant catechin. Thereby a novel route based on emulsion electrospinning is investigated to obtain tailored and sustained release rates for chatechin. The activity of the released catechin was assessed for its influence on multi-walled carbon nanotube (MWCNT) induced formation of reactive oxygen species (ROS) in the human alveolar epithelial the cell line A549. Homogenous fiber morphologies were obtained at specified ranges of PLGA concentrations within the emulsions including the formation of a core - sheath structure localizing the drug within the fiber core. In vitro measurements of the delivery showed moderate burst release kinetics in a first phase followed by a linear and smooth release at long term. In combination with polymer degradation studies a mostly diffusion controlled release mechanism was revealed exhibiting only marginal degradation of the polymer during the time span of the drug delivery. As a proof of concept, the activity of released catechin in A549 cells stimulated with MWCNTs was determined and revealed a high reduction of ROS production in a dose dependent manner. This effect diminishes over time indicating a depletion of catechin.