Characterization of protein corona and its effect on cell internalization of silica nanoparticles

Author(s)

Flávia Elisa Galdino

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2023-07-04

Examining board members

Mateus Borba Cardoso; Watson Loh; Marcelo Bispo de Jesus; Leandro Ramos Souza Barbosa; Amauri Jardim de Paula

• Advisor: Mateus Borba Cardoso

Abstract

Nanoparticles have been great alternatives for applications in medicine as drug carriers and platforms for vaccines and disease diagnosis. The interaction of these nanomaterials with biological systems involves several processes, from interaction with biological fluids to internalization in target cells. When exposed to biological fluids, nanoparticles are spontaneously covered by a protein layer called protein corona which, after formation, leads to the interaction of these nanomaterials with the biological system. For some applications, the control of protein corona formation is desired to use as a stabilizer and targeting. However, many fundamental characterizations of this layer of proteins, such as the morphology and thickness, are still major challenges that prevent a complete understanding of its formation. On the other hand, for other applications, it is necessary to avoid the formation of the protein corona, and the functionalization of nanoparticles surface with zwitterionic groups or polyethylene glycol (PEG) is one of the strategies used for this purpose. The adsorbed proteins and these functionalizations directly affect the interaction and internalization of nanoparticles in cells, and understanding this effect is crucial for the development of nanomaterials applied in therapies and disease diagnoses. Thus, the objective of this study is to use new characterization tools to elucidate fundamental aspects of the protein corona and investigate the impact of protein and zwitterionic or PEG functionalizations on the interaction, internalization, and fate of silica nanoparticles in mammalian cells. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) techniques were used to characterize the binding constant, thickness, and morphology of the protein corona. The protein corona of bovine serum albumin was determined to have a heterogeneous thickness averaging about 8 nm and a hard corona of 4 nm. In addition, the effect of proteins and functionalizations on nanoparticle-cell interaction was investigated. To obtain a comprehensive understanding of the internalization processes and nanoparticle pathways in the cells, complementary techniques such as widefield, super-resolution, and total internal reflection fluorescence microscopies, as well as TEM and soft x-ray microscopies, were used. The results revealed that nanoparticles coated with proteins exhibit the highest rates of internalization. These nanoparticles are taken up by vesicles and directed towards the perinuclear region (AU)

• FAPESP's process: 18/09555-9 - Influence of protein corona on interaction and internalization of silica nanoparticles in human cells: from two-dimensional to tri-dimensional images
• Grantee: Flávia Elisa Galdino
• Support Opportunities: Scholarships in Brazil - Doctorate