Preparation of size-controlled bovine serum albumin (BSA) nanoparticles by a modified desolvation method

The size effect of nanomaterials is of major interest, since it may affect their bioavailability and toxicity. In this study, bovine serum albumin (BSA) nanoparticles were prepared using a modified desolvation method. Bare BSA nanoparticles and calcium (Ca)-loaded BSA nanoparticles were fabricated at the targeted sizes, 100, 400, and 800 nm. The mean diameters of the prepared BSA nanoparticles were 125, 393, and 713 nm; those of the Ca-BSA nanoparticles were 260, 353, and 919 nm. The surface-area-to-volume-ratios of the prepared BSA nanoparticles were 4.82, 1.53, and 1.03 nm−1; those of the Ca-BSA nanoparticles were 2.34, 1.72, and 0.90 nm−1. The size and the surface-area-to-volume-ratio of the BSA nanoparticles were controlled by adjusting BSA concentration, pH, and NaCl content, which affected the coagulation of the BSA molecules. The surface-area-to-volume-ratio is a more useful parameter than the mean diameter of particles for comparing effectiveness of nanoparticles.

Research highlights
► Nanoparticles of a controlled size are important to ascertain size effect in food.
► Difference in manufacturing processes affects particle properties.
► Different-size similar-surface particles are good tools to study size effect.
► Size-controlled BSA nanoparticles are prepared by similar manufacturing processes.
► Size-controlled BSA nanoparticles prepared are useful as standard materials.