Study of pH and ionic strength influence on the physicochemical properties of Au:pDNA:Protamine nanoparticles aiming at DNA vaccination

• Grant number: 15/17456-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2015
• End date: July 31, 2016
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Adriano Rodrigues Azzoni
• Grantee: Caio Henrique de Souza Santos
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The use of non-viral vectors like plasmid DNA (pDNA) in gene therapy and DNA vaccination studies has been limited by their low efficiency compared to viral vectors. This is mainly due to the limited capacity to overcome physical, enzymatic and diffusional barriers in the transport to the nuclei of target cells. Besides that limitation, the lack of systematic studies of the influence of non-viral vectors characteristics on gene delivery limits their use. We have been observing that the efficiency is highly influenced by the physicochemical characteristics of non-viral vectors, particularly charge, size and morphology, which are influenced by their environment of complexation. The main objective of this scientific initiation study is the characterization of ternary complexes of gold nanoparticles (AuNP), plasmid DNA (pDNA) and protamine protein formed in different pH and ionic force conditions. The complexes are going to be characterized by transmission electron spectrometry, zeta potential and light scattering. These data will then be correlated with the results of the transfection efficiency of mammalian cell in culture (HeLa), by the quantification of the expression of reporter gene GFP carried in the used model plasmid (pVAX1GFP). In addition to incentivating and training a young student in research practices, it is expected as a result of this research a better comprehension of the phenomena involved in the assembly of these transfectants particles, also known as "artificial viruses".