Probing the nanobiointerface: dynamic, structure and binding ratio of plasma proteins adsorbed onto biocompatible polymeric micelles and polymersomes

• Grant number: 16/11431-0
• Support Opportunities: Scholarships abroad - Research
• Start date: May 01, 2017
• End date: April 30, 2018
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Fernando Carlos Giacomelli
• Grantee: Fernando Carlos Giacomelli
• Host Investigator: Sébastien Lecommandoux
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Institution abroad: Laboratoire de Chimie des Polymères Organiques (LCPO), France

Abstract

The investigations will be devoted to the influence of polymeric nanoparticles' morphology on the interaction and adsorption with plasma proteins. Initially, polymeric micelles and polymersomes will be produced from novel synthesized pH-responsive and biocompatible block copolymers made as PHPMAm-b-PDPAn with different PHPMA/PDPA ratios. They will be deeply characterized by using a variety of scattering techniques (dynamic light scattering - DLS, static light scattering - SLS, electrophoretic light scattering - ELS and small-angle x-ray scattering - SAXS) besides transmission electron microscopy (cryo-TEM). Subsequently, it will be evaluated the adsorption of different plasma proteins onto the surface of the produced polymeric assemblies with further discussions in relation with structural features, particularly their morphology. The interaction and adsorption of distinct plasma proteins (HSA, IgG, fibrinogen, APoA1 and lysozyme) onto polymeric micelles and vesicles will be investigated taking into account the binding dynamics, binding affinity, binding ratio as well as protein conformational changes due to binding. The binding dynamics will be monitored essentially via dynamic and electrophoretic light scattering measurements. Accordingly, changes in size, size distribution and surface charge will be monitored as a function of time. The static light scattering measurements will be employed to determine the molecular weight of the nanoparticle-protein complexes and accordingly, the binding ratio, which means the amount of different protein adsorbed onto the surface of the polymeric assemblies. Thermodynamic informations such as number of binding sites and binding constants will be determined by isothermal titration calorimetry (ITC) and accordingly, it will possibly allow us to get informations related to the mechanisms of binding and primary intermolecular forces involved. Finally, possible protein conformational changes due to the adsorption phenomena will be probed via circular dichroism, fluorescence and Raman spectroscopy. (AU)