Banca de QUALIFICAÇÃO: THAÍS DA SILVA CORRÊA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : THAÍS DA SILVA CORRÊA
DATE: 01/12/2023
TIME: 14:00
LOCAL: https://meet.google.com/osr-atth-rpj
TITLE:

synthesis, characterization and cytotoxicity of silver nanoparticles obtained from different yeasts

KEY WORDS:

Silver nanoparticles, green synthesis, antitumor action, antimicrobial effect.

PAGES: null
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Silver nanoparticles (AgNP) are antitumor and antimicrobial agents. Green synthesis (SV) of AgNP reduces the use of toxic reagents required in chemical synthesis. Among the biological materials capable of reducing silver salts, forming and stabilizing AgNPs, yeast stands out for its rapid growth in low-cost culture media. Furthermore, its bioactive molecules can contribute to a synergistic action in the intended biomedical application. The objective of this work was to produce, by SV, AgNP for antitumor and antimicrobial application, using two species of yeast. Different SV protocols were evaluated using the culture supernatant, the supernatant after incubating the biomass in ultrapure water or yeast extract. Parameters such as silver nitrate concentration, pH and reaction time were varied. SV was evaluated by spectroscopy (UV-vis) and the AgNPs obtained were characterized. AgNPs suitable for biomedical application were used in preliminary in vitro tests to evaluate cytotoxicity in tumor lines (4T1luc and CT26) through MTT assay and for antimicrobial potential against Klebsiella pneumoniae, Staphylococcus aureus and Candida albicans. Among the protocols evaluated, the cultivation of biomass in ultrapure water was the most effective, as it produced AgNP with a hydrodynamic diameter <250 nm, zeta potential < - 20 or >20 and polydispersity index (PDI) <0.4. SV from yeast 2 resulted in smaller AgNPs (89 to 138 nm) and more homogeneous (PDI < 3) than SV from yeast 1 (diameter between 196 and 242 nm and PDI between 0.3 and 0.4) . The MTT tests showed that all AgNPs produced by both yeasts with the ultrapure water protocol were able to reduce the viability of strains 4T1 and CT26, the latter being more sensitive. The preliminary antimicrobial activity test showed potential for the AgNPs produced, being capable of inhibiting the growth of the bacteria K. pneumoniae and S. aureus and the yeast C. albicans. It can be concluded that the SV of AgNP was carried out successfully. After determining the concentration of AgNPs produced (in progress), new in vitro cytotoxicity tests (including non-tumor cells) and antimicrobial activity (against all bacteria from the ESKAPE group and C. albicans) will be carried out to confirm antitumor and antimicrobial potential. of AgNP.

BANKING MEMBERS:
Presidente - 2059999 - MARIANA CAMPOS DA PAZ LOPES GALDINO
Interno - 1757978 - DANIEL BONOTO GONCALVES
Externa ao Programa - 1349713 - DANIELA LEITE FABRINO