Advanced search
Start date
Betweenand


Colloidal stability and protein corona: fundamental aspects for maintaining silica nanoparticle properties in biological media

Full text
Author(s):
Gabriela Borba Mondo
Total Authors: 1
Document type: Doctoral Thesis
Press: Campinas, SP.
Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
Defense date:
Examining board members:
Mateus Borba Cardoso; Celso Aparecido Bertran; Camila Alves de Rezende; Leandro Ramos Souza Barbosa
Advisor: Mateus Borba Cardoso; Watson Loh
Abstract

Nanomedicine has attracted attention for its potential for diagnosis and therapy. However, absence of coloidal stability and formation of protein corona (PC) have hindered the clinical translation of nanoparticles (NP). In this work, silica nanoparticles (SiO2NP) were functionalized and evaluated regarding the spontaneous formation of PC and the colloidal stability in physiological media. Measurements of light scattering have shown that bare SiO2NP adsorb BSA, presenting a saturation that is dependent on the medium, while SiO2NP functionalized with poly(ethylene glycol) and zwitterionic sulfobetaine moieties were capable of suppressing BSA adsorption. Saturation with a BSA corona over SiO2NP has been demonstrated to be an important element to provide protection against aggregation induced by freeze-drying process, evidencing that specific protein coronas can be explored for some applications. Regarding the correlation of colloidal stability in biological-relevant media and nanoparticle charge, SiO2NP functionalized with a sulfobetaine zwitterionic were evaluated, due to their remarkable colloidal stability in media containing high ionic strength and protein concentrations, despite their observed negative charge. Several procedures were carried aiming to obtain neutral nanoparticles, as described in literature, as well as to elucidate the source of this negative charge. Using molecular theory simulations, the negative charge for zwitterionic sulfobetaine-modified nanoparticles were attributed to stabilization of the negative charged siloxide groups in the silica surface by the positive quaternary amines of the sulfobetaine moiety. Lastly, bioconjugation of the cysteine aminoacid was performed through its distinct functional groups, to bioconjugation techniques that can be used for future production of a chemically bound protein corona (AU)

FAPESP's process: 16/16905-0 - Colloidal stability and protein corona: fundamental aspects for maintaining silica nanoparticle properties in biologial media
Grantee:Gabriela Borba Mondo
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)