PULSin was used in combination with a multistage vector system to facilitate cellular internalization of pyruvate decarboxylase. The cells were exposed to PULSin (1.2 l/well), pyruvate decarboxylase (0.3 g/well), or PULSin/pyruvate decarboxylase (0.3 g protein/1.2 l PULSin/well) in serum-free media for 4 h, after which the media was replaced with media containing 1% FBS.

Cancer cells have high rates of glycolysis and lactic acid fermentation in order to fuel accelerated rates of cell division (Warburg effect). Here, we present a strategy for merging cancer and yeast metabolism to remove pyruvate, a key intermediate of cancer cell metabolism, and produce the toxic compound acetaldehyde. This approach was achieved by administering the yeast enzyme pyruvate decarboxylase to triple negative breast cancer cells. To overcome the challenges of protein delivery, a nanoparticle-based system consisting of cationic lipids and porous silicon were employed to obtain efficient intracellular uptake. The results demonstrate that the enzyme therapy decreases cancer cell viability through production of acetaldehyde and reduction of lactic acid fermentation.