Comparative analysis of the efficacy of quercitin-loaded PLGA-MNP delivered to A549 cells via direct pippetting or nebulization. A549 cells growing on 96-well tissue culture plates were exposed to various concentrations (ranging from 10 to 250 μg/ml) of empty or quercitin-loaded PLGA-MNP by direct pippetting (A) or nebulization (B). Following treatment, cells were incubated for 24 h, washed and fixed. HCS assay was performed using IN Cell Analyzer-1000 equipped with Investigator software by quantifying cell adherence to the plates. Values in the plotted as line graph are fold change in viable cell numbers ± SEM of three independent experiments in triplicate from five randomly selected fields/well containing at least 300 cells. *p < 0.05. Quercetin alone could not be used as a control due to its poor aqueous solubility.