Banca de QUALIFICAÇÃO: ALZIRA REGINA SILVA DE DEUS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALZIRA REGINA SILVA DE DEUS
DATE: 29/10/2025
TIME: 14:00
LOCAL: VIDEOCONFERÊNCIA
TITLE:

DEVELOPMENT OF NANOSYSTEMS FOR EXPERIMENTAL IMMUNIZATION
APPLIED TO VISCERAL LEISHMANIASIS

 

KEY WORDS:

PLA nanoparticles; polyethylenimine; Leishmania infantum; neglected tropical diseases.

PAGES: 110
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

This study developed and characterized poly(lactic acid) (PLA) nanoparticles functionalized with polyethylenimine (PEI) and incorporated with Leishmania infantum protein extract, aiming to assess their applicability as an immunotherapeutic strategy against visceral leishmaniasis. The nanoparticles were obtained by nanoprecipitation, exhibiting spherical shape and satisfactory physicochemical stability for 30 days, even after functionalization with PEI and the antigenic extract. Evaluations using dynamic light scattering (DLS), zeta potential, and scanning electron microscopy (SEM) confirmed the encapsulation efficiency as well as the morphological integrity of the nanoparticles. The cytotoxicity of the systems was investigated in vitro in fibroblast (3T3) and macrophage (RAW 264) cell lines. The blank nanoparticles showed low toxicity, while the cationic systems exhibited concentration-dependent cytotoxicity. Functionalization with protein extract mitigated adverse effects in some assays, suggesting modulation of the interaction between the nanoparticles and the cells. The immunogenic efficacy of the nanosystems was evaluated in vivo through immunization of BALB/c mice. The animals were divided into four experimental groups and monitored for total IgG and IgG subclasses (IgG1, IgG2a, IgG2b, and IgG3) production over 60 days. Results showed that all immunized groups had a significant increase in IgG production, with peaks at different time points. Although the highest IgG levels were observed in the control groups with free extract or extract + aluminum, the groups treated with nanoparticles also induced a sustained humoral response. Analysis of IgG subclasses revealed a predominance of IgG2b and IgG3 in the nanoparticle groups, suggesting a Th1-type immune response, which is more effective against intracellular infections such as leishmaniasis. Furthermore, the nanoparticles’ ability to protect the extract from degradation and promote controlled release reinforces their potential as a vaccine adjuvant. In conclusion, the developed nanosystems are promising tools for immunotherapy of visceral leishmaniasis, exhibiting favorable characteristics such as stability, low toxicity, and the ability to modulate the immune response. Future studies should further investigate the underlying immunomodulatory mechanisms to optimize their vaccine efficacy.

COMMITTEE MEMBERS:
Externa à Instituição - ARIANE FERREIRA LACERDA - IFGoiano
Externa à Instituição - CLAUDIA JASSICA MORENO - NOVA
Externo à Instituição - EMANUELL DOS SANTOS SILVA - FACENE
Presidente - 1544647 - MATHEUS DE FREITAS FERNANDES PEDROSA