Self-assembled albumin nanoparticles for redox responsive release of curcumin

The synthesis of stimuli-responsive protein-based nanocarriers often involves multi-step processing or use of toxic crosslinkers, which impede their wide-spread utilization as drug delivery systems. In this study, we report a facile, self-assembly based method for the synthesis of redox responsive albumin nanocarriers (<150 nm) without the use of crosslinkers. Curcumin (CUR) was encapsulated into these self-assembled albumin nanoparticles with 83.22% encapsulation efficiency and 8.33% loading capacity. These CUR loaded redox responsive albumin nanoparticles displayed glutathione (GSH) triggered CUR release due to the reduction of disulfide bonds in the protein structure. The release studies show that in the presence of GSH, 61% of the CUR is released, whereas in GSH-free environment only 18% of the drug is released within the first 12 h. In vitro studies performed on triple negative human breast cancer cells (MDA-MB-231) show that encapsulation of CUR provided enhanced cytotoxicity compared to free CUR. Furthermore, studies on the mitochondrial structure of these cells confirm that the drug loaded nanoparticles lead to the changes in mitochondria stress conditions by reacting with the GSH in the cells.