Spectrin conjugated PLGA nanoparticles for potential membrane phospholipid interactions: Development, optimization and in vitro studies

The distorted membrane asymmetry and abnormal distribution of phospholipids viz., phosphatidylserine (PS), and phosphatidylethanolamine (PE) in the outer leaflet are critical features of cancer. In the present study, the blood protein spectrin (SPN) was used as a ligand due to it PS-binding affinity and drug nisin was used because it disrupts and fluidized the plasma membrane. Polymeric poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) were prepared and optimized by the Response surface Box Behnken randomized model using various independent and dependent variables. The optimized-nanoparticles (NNP2) were further conjugated with SPN, and conjugation was confirmed by infrared spectroscopy, and in silico docking, the analysis was also conducted for the ligand-polymer interactions. Both nanoparticulate formulations were further characterized for mean particle size, drug entrapment, zeta potential, surface morphology, and in vitro drug release and kinetic study. The results indicated that the prepared formulations were in spherical, nano-metric size with -ve zeta potential. More than 64% drug entrapment with 85% drug released after 72 h were found in both types of formulations. In vitro cytotoxicity study was performed by sulforhodamine blue assay on MDA-MB-231 (breast cancer), and FR-2 (normal breast epithelial) cell lines and results showed the IC50 of unconjugated and SPN-conjugated nanoparticles 13.0 mu g/mL and 0.06 mu g/mL, respectively on MDA-MB-231 whereas 276.11 mu g/mL and 142.99 mu g/mL on FR-2. Briefly, results suggest that the developed nanoparticles could be used for better cancer treatment without any harmful effects on adjacent normal cells.