In Vitro Cytotoxicity of Polymeric Nanoparticles Coated with Lipid Layer Loaded with Cardiovascular Drugs ^†

Nanomedicine is a rapidly growing field that uses nanotechnology to solve clinical problems—mainly diseases with a high risk of mortality (e.g., cardiovascular and cancer diseases). A new class of nanoparticles, polymeric nanoparticles coated with lipid layers, aimed at combining the advantages of both polymeric nanoparticles and lipid vesicles, has received attention in recent years [1]. Since cytotoxicity is one of the most important indicators for biological evaluation in in vitro studies, the main aim of this study was to investigate the cytotoxicity of polymeric nanoparticles coated with a lipid layer loaded with a mixture of two cardiovascular active pharmaceutical ingredients (APIs) on a human epithelial cell line [2,3]. Polymeric nanoparticles coated with a lipid layer were prepared via a nanoprecipitation method using poly(lactide-co-glycolide) (PLGA), Pluronic F127 and phosphatidylcholine. The APIs loaded in nanoparticles were valsartan and amlodipine besylate, used mainly in cardiovascular disease therapy. The nanoparticles were characterized by entrapment efficiency, size and polidispersity index using spectrophotometric and dynamic light spectrophotometry (DLS). Additionally, the nanoparticles were investigated in terms of cytotoxicity in comparison with the sample without lipid material(phosphatidylcholine). The cytotoxicity of these nanoparticles was evaluated through the tetrazolium-based colorimetric assay (MTT) on human epithelial cells. The MTT assay involves the NAD(P)H-dependent cellular oxidoreductase enzyme that converts the yellow tetrazolium MTT into insoluble compound (formazan), which was dissolved with dimethyl sulfoxide (DMSO) to give a purple color with a characteristic absorption at 540 nm [4]. The intensity of the purple color is directly proportional to the cell number and thus indicates the cell viability. DLS analysis of nanoparticles indicated sizes lower than 300 nm with good dispersity (polydispersity index < 0.3). Nanoparticles showed a higher encapsulation for amlodipin and valsartan as well. Both samples with and without lipid material showed no significant cytotoxicity on a human epithelial cell line. Polymeric nanoparticles coated with a lipid layer represent an important potential drug delivery system for future cardiovascular applications.