Enzyme delivery using the 30Kc19 protein and human serum albumin nanoparticles

Abstract Nanoparticles have been widely used for delivering various chemical and biomolecular drugs, such as anti-cancer drugs and therapeutic proteins. Among nanoparticles, protein nanoparticles have advantages of non-cytotoxicity and biodegradability. In this study, a recombinant 30Kc19 protein was applied to human serum albumin (HSA) nanoparticles to enhance cellular uptake and stability of a nanoparticle cargo enzyme. The 30Kc19 protein, which originates from silkworm, has cell-penetrating and enzyme-stabilizing abilities. Therefore, 30Kc19–HSA nanoparticles were expected to enhance cellular uptake and stability of an enzyme loaded on the nanoparticles. Here, nanoparticles loaded with β-galactosidase were prepared using the desolvation method. The 30Kc19–HSA nanoparticles were uniformly spherical in shape, dispersed evenly in phosphate buffered saline and cell culture media, and released β-galactosidase in a sustained manner. The 30Kc19–HSA nanoparticles had negligible toxicity to animal cells and exhibited enhanced cellular uptake and intracellular stability of β-galactosidase in HeLa and HEK293 cells when compared with those of HSA nanoparticles. These results suggest that 30Kc19–HSA protein nanoparticles could be used as a versatile tool for drug delivery to various cells.