Banca de QUALIFICAÇÃO: IVY SANTOS SOARES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : IVY SANTOS SOARES
DATE: 31/03/2023
TIME: 09:00
LOCAL: PLATAFORMA RNP
TITLE:

Synthesis and evaluation of the photoprotective, pro-oxidant, antioxidant and antibacterial capacity of carbon dots for application in the treatment of diabetic foot ulcers

KEY WORDS:

Nanoparticle; free radicals; fluorescence; antibacterial; ulcers

PAGES: 55
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

Diabetic foot ulcers (DFUs) are one of the most serious consequences of diabetes mellitus (DM), since in severe cases they can lead to amputations or death. Despite the methods of treating DFUs, there is a demand for new approaches that allow for more efficient, low side effects, non-invasive features that can prevent and treat the onset of such a condition. In this context, carbon dots (CDs) emerge as promising nanoparticles in the treatment of DFUs by exhibiting low toxicity, biocompatibility, photostability, low cost, tunable luminescence, etc. In this sense, the present work aims to produce CDs from citric acid and urea (CDU), citric acid and polyethyleneimine (CDPEI), citric acid and neutral red (CDNR), paraphenylenediamine (PPD) and lemon pomace CDL-H via microwave and hydrothermal methods to act as photoprotective, antibacterial, antioxidant and pro-oxidant agent in the treatment of DFUs. The CDs showed size less than 10 nm and surface groups characteristic of the precursors used. Moreover, the UV-Vis spectra of the CDs showed absorption typical of the π- π* transitions of the graphitic core and n- π* transitions of the surface states. The FTIR spectra of the CDs exhibited vibrations characteristic of oxygenated and nitrogenated groups and excellent photostability. The CDU and CDL-H CDs exhibited excitation wavelength-dependent emission (λexc) with maximum in green at 540 nm (ʎexc= 480 nm) and blue at 450 nm (ʎexc= 330 nm), respectively. On the other hand, PPD and CDPEI exhibited λexc-independent emission with maximum centered at 600 and 450 nm, respectively. CDNR exhibited dual emission centered at 475 and 600 nm. Fluorescent films based on the aforementioned CDS and biopolymers were synthesized and all exhibited tunable emission, flexibility and transparency. The previous results indicated that the CDs acted effectively in generating singleto oxygen, as well as were able to capture both radical and non-radical oxygen species, reaching values higher than 70 % under optimized conditions. The CDs also exhibited promising results with regard to photoprotective and antibacterial capacity. Moreover, the CDs exhibited a viability of more than 80 % against human non-tumoral skin fibroblast cells (HFF-1). Finally, the CDs showed promising results to act in the treatment of DFUs

BANKING MEMBERS:
Interno(a) - 1121343 - ANA MARIA QUEIJEIRO LOPEZ
Interno(a) - 1318707 - ARACELIS JOSE PAMPHILE ADRIAN
Presidente - 1869296 - CINTYA D'ANGELES DO ESPIRITO SANTO BARBOSA
Externo(a) à Instituição - GEORGE RICARDO SANTANA ANDRADE
Interno(a) - 1006306 - JADRIANE DE ALMEIDA XAVIER