Abstract
Here we present the development of nanoparticles (NPs) formulations specifically designed for targeting the antiapoptotic Bcl-2 proteins on the outer membrane of mitochondria with the drug agent ABT-737. The NPs which are self-assembled by the natural polypeptide poly gamma glutamic acid (ϒPGA) and a designed cationic and amphiphilic peptide (PFK) have been shown to target drugs toward mitochondria. In this study we systematically developed the formulation of such NPs loaded with the ABT-737 and demonstrated the cytotoxic effect of the best identified formulation on MDA-MB-231 cells. Our findings emphasize the critical role of solutions pH and the charged state of the components throughout the formulation process as well as the concentrations of the co-components and their mixing sequence, in achieving the most stable and effective cytotoxic formulation. Our study highlights the potential versatility of designed peptides in combination with biopolymers for improving drug delivery formulations and enhance their targeting abilities.