The interaction between biomimetic nanoparticles and biological fluids: the role of protein corona

Nanoparticles (NPs) hold significant potential in the field of nanomedicine, serving as a primary focus of research for the development of innovative solutions to the limitations of conventional pharmaceuticals. Within this field, a diverse array of nanoplatforms has been developed and utilized, particularly in cancer treatment, including inorganic, lipid-based, and engineered biomimetic nanoparticles. These advancements have facilitated the creation of more specific, efficient, and safer therapeutic strategies, thereby contributing to the ongoing progress of personalized medicine. All these systems are designed with a specific biomedical purpose. However, once administered, NPs interact with the biological environment, initiating a dynamic process in which circulating biomolecules, mainly proteins, adsorb and desorb from the NP surface. This interaction, dependent on the NP physico-chemical properties and on the binding affinities of different proteins, results in the formation of the "Protein Corona" (PC), which confers a new biological identity to the nanoparticles. PC formation can influence NP stability, colloidal behaviour, while also playing a critical role in immune recognition, potentially affecting NP immunogenicity. Additionally, the PC may mask the intended function of NPs, reducing their therapeutic efficacy. To mitigate the challenges posed by PC formation, strategies such as PEGylation and other coating have been explored. This Master Thesis aims to investigate the dynamics of PC formation on iron-doped zinc oxide nanoparticles, comparing pristine NPs with biomimetic counterparts coated with various lipid formulations. The presented work includes the synthesis and functionalization of iron-doped zinc oxide nanoparticles using a wet chemical method, followed by their characterization through dynamic light scattering (DLS), zeta potential measurements, and field emission scanning electron microscopy (FESEM). The coating process based on solvent exchange for the production of biomimetic nanoparticles is also detailed. Subsequently, NP interactions with biological media, including cell culture medium and human plasma, are studied through incubation at various time points. NP stability is evaluated by analysing changes in size and surface charge, providing insights into PC formation. Protein adsorption is investigated using colorimetric assays and gel electrophoresis. Finally, the effects of PC on NPs internalization into cells are examined, with a focus on alterations in NP-cell interactions. Ultimately, this work offers insights into the role of the PC in modulating the biological behaviour of NPs, emphasizing the differences that arise when employing lipid coatings. This understanding can facilitate the rational design of highly effective biomimetic nanosystems for therapeutic applications.