Título:	Avaliação e caracterização de C-DOTS com oleos essenciais de cravo, citronela e laranja para aplicações biologicas – um estudo com larvas de Zophobas morio
Autor(es):	Brito Neta, Maria de Sousa
Orientador(es):	Azevedo, Ricardo Bentes de
Assunto:	Óleos essenciais Nanotecnologia Toxicidade Antioxidantes
Data de publicação:	22-Jul-2024
Data de defesa:	23-Dez-2022
Referência:	BRITO NETA, Maria de Sousa. Avaliação e caracterização de C-DOTS com oleos essenciais de cravo, citronela e laranja para aplicações biologicas– um estudo com larvas de Zophobas morio. 2022. 146 f., il. Tese (Doutorado em Biologia Animal) — Universidade de Brasília, Brasília, 2022.
Abstract:	Seeking at the use of raw material or products that allow an economic, environmental sustainability and low toxicity for human’s application, we use nanotechnology based in carbon dots, associated with essential oils which have several biological applications with microbiological and antioxidant properties. Thus, the main objective of this work was to functionalize carbon dot nanoparticles-(DOTS) with three essential oils: citronella (Cymbopogon winterianus) – (DCIT); clove (Eugenia caryophyllus) - (DCRA), and orange (Citrus sinensis) - (DLAR) that could promote a greater solubility, better molecular stability and lower toxicity for the oils and DOTS. The degree of purity of each oil used in the work was determined by gas chromatography coupled with mass spectrometry (GC-MS) analysis. After nanoparticles functionalization’s, all formulations were analyzed by thermogravimetry (TG), UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and RAMAN to determine their physicochemical parameters, as well as transmission microscopy (MET) for size evaluation, pH variation, and presence of antioxidants by magnetic resonance technique (EPR). The Zophobas morio larvae (superworms) was the in vivo model used to evaluate toxicity and antioxidant markers such as Nitrite, Myeloperoxidase (MPO) and Reduced Glutathione (GSH) and Melanization. The oils purity was more than 85%. For the major compounds of clove oils, eugenol purity was 85% and β- Caryophyllene 11%. The orange oil represented by limonene presented 97% purity. For citronella oil the three most representative molecules with their purity degree respectively are citronellal 41%, geraniol 23% and citronellol 8.6%. Data from RAMAN analyses showed that DOTS at room temperature showed an increase in the content of structural defects over time, due to oxidative processes induced by oxygen in the medium; on the other hand, the presence of oil on the surface of DOTS promoted a stability in the bonds with the oils, for DCRA it was six months and the DLAR and DCIT formulations were of twelve months. FTIR data show additional spectra bands in ~1450 cm-1 , associated with symmetrical carboxyl stretch modes. Vibrational modes and C=O) can be found in 1670 cmand 1715cm-1 , respectively, displacement to higher energies as well as the increase in the intensities of the modes associated with the oxygenated groups, indicating once again the oxidation of the DOTS surface. In the UV-Vis analyzes, the absorption spectra of DOTS, DLAR and DCIT, presented a typical absorption band at 337 nm as a n–π* transition (C=O bonds) and a shoulder around 240 nm, attributed to the π-π* transition (C=C bonds with sp2 hybridization); in the DCRA, the shoulder around 238 nm was not observed, for transitions π-π*, but it was presented an atypical peak, at 279 nm. It was found that only the DCRA formulation presented a potential antioxidant, while DOTS, DLAR and DCIT, with similar behavior, the decay average was from 100 to 60% in the consumption of DPPH showing a lower degree of antioxidant effect. No death was observed in vivo studies after 48h of formulation administration, and the production of free radicals and antioxidants associated with Nitrite, GDH and MPO were dependent on the concentrations of each formulations. For the detection of Nitrite, only two formulations presented alterations; DCRA at concentrations of 25 and 100 mg/g of animal and DCIT at 25 and 50 mg/g. Changes in GSH values were observed in the DCRA at 25 mg/g, DOTS at 50 and 100mg/g and DLAR in 50mg/g. MPO levels were altered in all concentrations of DOTS and DCIT tested, and for DCRA only in 50mg/g of animal. Melanization presented alterations only to the Formulation DCRA at concentrations of 50 and 25 mg/g of animal. The results presented, demonstrated that the carbon-dots functionalized with essential oils used in this study can produce DOTS with reduced toxicity and a better antioxidant property for potential applications in biocompatible products.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB)
Informações adicionais:	Tese (doutorado) — Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Animal, 2022.
Programa de pós-graduação:	Programa de Pós-Graduação em Biologia Animal
Licença:	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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