A comparative study of cross-linked human serum albumin nanoparticles using ultrasonication or glutaraldehyde; The impact on the corona protein adsorption using SDS-PAGE and MALDI-TOF

Protein-based nanoparticles (NPs) are promising delivery systems designed for many drugs, including anticancer drugs. In this study, human serum albumin (HSA) in solution and once nanoparticulated by the desolvation method were crosslinked using ultrasonication, and their characteristics were compared to glutaraldehyde (GA) crosslinked HSA solution and nanoparticles (NPs). The results revealed that ultrasonic irradiation caused the development of new intermolecular disulfide bonds between albumin molecules, perhaps via the production of free radical species. The sonicated NPs were then compared with the GA cross-linked NPs in terms of size, shape, surface charge, and functional groups. Furthermore, the corona protein of the produced HSA NPs was examined using SDS-PAGE and MALDI-TOF since protein adsorption plays a significant role in the biological fate of NPs. The findings showed that while the morphologies of the sonicated and GA-NPs were comparable, the particle sizes (224 vs. 174 nm) and zeta potentials (+27.5 vs. -6.4 mV) were different. SDS-PAGE results showed that the protein bands adsorbed onto the surface of the sonicated nanoparticles were more intense. This could be connected to the distinct surface characteristics and surface charge of the ultrasonically irradiated NPs. In summary, the preparation of cross-linked HSA NPs using disulfide bound rearrangement, which led to the positively charged albumin NPs is reported. Moreover, ultrasonic irradiation can be introduced as an alternative method to avoid the toxic residual of cross-linking agents in HSA NPs production.