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| Author(s): |
Jessica Fernanda Affonso de Oliveira
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2019-05-22 |
| Examining board members: |
Mateus Borba Cardoso;
Celso Aparecido Bertran;
Italo Odone Mazali;
Eliana Martins Lima;
Diego Stéfani Teodoro Martinez
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| Advisor: | Edvaldo Sabadini; Mateus Borba Cardoso |
| Abstract | |
The present work describes the synthesis of silica nanoparticles (SiO2NPs) used on the antitumor drug doxorubicin (DOX) encapsulation and subsequent functionalization with the monoclonal antibody Ki-1, for CD30+ lymphoma cells treatment. Due to their physico-chemical properties and the efficient transport of biologically active molecules, SiO2NPs have been considered promising drug delivery systems. However, when SiO2NPs are in contact with biological fluids, proteins tend to adsorb on their surface, forming a coating known as the protein corona, consequently affecting their biological interaction. In this context, the first challenge to be transposed is to prevent nonspecific proteins adsorption on the SiO2NPs surface. Thus, we propose a surface modification to obtain dual functionalization, in order to modulate their behavior in vitro. Therefore, the functionalization of SiO2NPs was performed with the zwitterionic sulfobetaine, which provides colloidal stability and with 3-aminopropyltriethoxysilane (APTES), whose primary amines (-NH2) present in their chemical structure enable subsequent coupling reactions. We verified that the zwitterionic portion was very effective in the protein adsorption prevention, even in solutions with high protein concentration. This allowed the maintenance of the biological identity of the synthesized materials, allowing their subsequent interaction with the targeted cells. In addition, the second challenge of this work is related to the evaluation of the biological behavior and specificity of SiO2NPs functionalized with Ki-1 monoclonal antibody in cell assays. Ki-1 was chosen because of its specificity in the recognition of CD30 transmembrane protein, which is overexpressed in the cell membrane of Hodgkin's (LH) and anaplastic large cell (ALCL) lymphomas. Thus, cell viability assays were performed through flow cytometry with L540 and Karpas 299 cell lines, both CD30+. We investigated the selective targeting of Ki-1 functionalized materials, and we could observe that the non-functionalized SiO2NPs show negligible cytotoxic effect, maintaining cell viability above 90%. On the other hand, Ki-1 functionalized nanoparticles showed ~ 30% reduction in the cellular viability for both L540 and Karpas 299. We believe that the cytotoxic effect of SiO2NPs is only observed when they are internalized. Thus, it is possible that the functionalization with Ki-1 favors the entry of the nanoparticles, through the interaction of the antibody with the membrane CD30 protein of the cells studied, resulting in cell receptor-mediated internalization. Confocal microscopy assays allowed to validate the hypothesis cited, but there is still a need for investigations that fully justify the internalization and consequent cytotoxicity caused by SiO2NPs. In this way, the present work is of fundamental contribution for the advancement of research related to the biological and selective targeting using nanoparticles. We present a surface modification strategy that, while maintaining the biological identity of the materials, favors the coupling with targeting molecules. This methodology can contribute to the stability and better bioavailability of encapsulated drugs, as well as reduce possible side effects presented by conventional chemotherapeutic treatments (AU) | |
| FAPESP's process: | 13/22429-9 - Synthesis of mesoporous silica nanoparticles functionalized with monoclonal antibodies: an alternative to Hodgkin (HL) and anaplastic large cell CD30+ (ALCL - CD30+) lymphomas treatment |
| Grantee: | Jessica Fernanda Affonso de Oliveira |
| Support Opportunities: | Scholarships in Brazil - Doctorate |