Luis Braz is an assistant teacher at Universidade do Algarve since 2007, and was previously a Pharmacy Technician (2000 – 2007) at Hospital de Santa Luzia – Viana do Castelo. At Universidade do Algarve he belongs to the Pharmacy degree course committee since 2010 and has supervised 3 MSc theses of Pharmaceutical Sciences students.
He finished is BSc in Pharmacy in 2001 and the MSc in Chemistry in 2006. He recently concluded the PhD in Pharmaceutical Sciences – Pharmaceutical Technology specialty at Faculdade de Farmácia da Universidade do Porto (2016).
As a researcher, Luis Braz was part of GISOCB – Faculdade de Ciências da Universidade do Porto (02/2003 – 03/2006) and CIQA – Universidade do Algarve (09/2009 – 10/2017), and now integrates CBMR – Universidade do Algarve (11/2017 – present). He has participated in more than 30 national/international congresses with 4 oral and 16 poster communications and published 4 articles in international peer-review journals. His scientific interests focus the use of natural polymers to develop drug delivery systems.
During the presentation will be discussed the design of nanoparticles based on locust bean gum (LBG) and chitosan to be used as oral immunoadjuvant for vaccination purposes. The advantages of oral immunization and the importance of LBG for this purpose will be explained. LBG-based nanoparticles were prepared by mild polyelectrolyte complexation between chitosan (CS) and a synthesized LBG sulfate derivative (LBGS), thus, this nanoparticle preparation methodology and the LBG derivative synthesis methodology will be addressed. The morphological characterization suggested that nanoparticles present a solid and compact structure with spherical-like shape. Sizes around 180-200 nm and a positive surface charge between + 9 mV and +14 mV were obtained. The cytotoxicity of the polymers and nanoparticles will be discussed and CS/LBGS nanoparticles did not affect cell viability of Caco-2 cells after 3 h and 24 h of exposure when tested at concentrations up to 1.0 mg/mL. Two model antigens (a particulate acellular extract HE of Salmonella enterica serovar Enteritidis, and ovalbumin as soluble antigen) were associated to CS/LBGS nanoparticles with efficiencies around 26% for ovalbumin and 32% for HE, which resulted in loading capacities up to 12%. The reason for using these two model antigens will be discussed. The association process did not affect the antigenicity of the associated antigens, confirming the mildness of the nanoparticle preparation methodology. BALB/c mice were orally immunized with ovalbumin-loaded nanoparticles (100 µg), and results indicate an adjuvant effect of the CS/LBGS nanoparticles, eliciting a balanced Th1/Th2 immune response. Therefore, CS/LBGS nanoparticles are promising as antigen mucosal delivery tools, with particular interest for oral administration.
Audience will learn:
•The audience will see that unusual polymers can be used to produce nanoparticles;
•The chemistry of these polymers can be tailored to fit the needed characteristics;
•This presentation can give attendees some new ideas that they can implement in their researches.