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Chemically oxidized cellulose, with 2,2,6,6-tetramethylpiperidine-1-oxyl reagent (TEMPO), has been considered, in the last decade, as one of the most attractive renewable materials for advanced applications, especially in the biomedical field. However, little information about its toxicological effects is available in the literature. The mutagenic potential and cytotoxicity tests reveal, at the first level of evidence, the toxicological effect of the materials, aiming at their safe use in the medical field. Therefore, the main goal of this study was to evaluate the mutagenic activity of TEMPO-oxidized cellulose nanofibers (CNF) by the Ames test and its cytotoxic potential by MTT assay. The Ames test was carried out using the changed strains of Salmonella typhimurium TA98, TA97a, TA100, and TA102, and the cytotoxicity tests were performed using the normal cell line GM07492A and human metabolizing cells (HepG2). The results showed that the modified cellulose did not increase the number of revertant colonies of S. typhimurium, indicating no mutagenic effect, and a low cytotoxic effect was found when compared with their respective negative controls. The results of the mutagenicity and cytotoxicity tests suggest it is harmless, supporting, at the first level of evidence, its safety potential to be used in the health and medical fields.

Made available in DSpace on 2020-12-12T02:49:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The aims of this work were to evaluate the antibacterial and antiproliferative potential in vitro of the metal complex with 4-aminobenzoic acid (Ag-pABA) and a drug delivery system based on bacterial cellulose (BC-Ag-pABA). The Ag-pABA complex was characterized by elemental analysis, high resolution mass spectrometry and single-crystal X-ray diffraction techniques, which indicated a 1:2 metal/pABA composition plus a nitrate ion coordinated to silver by the oxygen atom, with the coordination formula [Ag (C7H7NO2)2(NO3)]. The coordination of pABA to the silver ion occurred by the nitrogen atom. The in vitro antibacterial activity of the complex evaluated by minimum inhibitory concentration assays demonstrated the effective growth inhibitory activity against Gram-positive, Gram-negative biofilm producers and acid-alcohol resistant Bacillus. The antiproliferative activities against a panel of eight tumor cells demonstrated the activity of the complex with a significant selectivity index (SI). The DNA interaction capacity and the Ames Test indicated the absence of mutagenicity. The BC-Ag-pABA composite showed an effective capacity of sustained release of Ag-pABA. The observed results validate further studies on its mechanisms of action and the conditions that mediate the in vivo biological effects using animal models to confirm its safety and effectiveness for treatment of skin and soft tissues infected by bacterial pathogens, urinary tract infections and cancer. University of Araraquara – UNIARA Institute of Chemistry University of Campinas – UNICAMP Faculty of Pharmaceutical Sciences University of Campinas – UNICAMP São Paulo State University – UNESP School of Pharmaceutical Sciences Faculty of Medical Sciences University of Campinas – UNICAMP São Paulo State University – UNESP School of Pharmaceutical Sciences FAPESP: , 2015/09833-0 CAPES: 001 FAPESP: 019/03049-7 FAPESP: 13/07276-1 FAPESP: 2014/06779-2 FAPESP: 2015/20882-3 FAPESP: 2016/07729-4 FAPESP: 2017/16278-9 FAPESP: 2017/19243-1 FAPESP: 2018/00163-0 FAPESP: 2018/02344-2 FAPESP: 2018/12062-4 FAPESP: 2018/12590-0 FAPESP: 2018/25512-8 CNPq: 300968/2016-7 CNPq: 407822/2018

Foodborne diseases (FBDs) are a serious public health concern worldwide. In this scenario, preservatives based on natural products, especially plants, have attracted researchers' attention because they offer potential antimicrobial action as well as reduced health impact. The genus Copaifera spp., which is native of tropical South America and West Africa, contains several species for which pharmacological activities, including antibacterial effects, have been described. On the basis of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity (inhibition and eradication), preservative capacity, and Ames test, we evaluated the antibacterial, preservative, and mutagenic potential of Copaifera spp. oleoresins against the causative agents of FBDs. The Copaifera duckei, Copaifera reticulata, Copaifera paupera, and Copaifera pubiflora oleoresins displayed promising MIC/MBC values-from 12.5 to 100 μg/mL-against Staphylococcus aureus (American Type Culture Collection [ATCC] 29213), Listeria monocytogenes (ATCC 15313), and Bacillus cereus (ATCC 14579). C. duckei, C. reticulata, C. paupera, and C. pubiflora oleoresin concentrations ranging from 25 to 200 μg/mL and from 100 to 400 μg/mL inhibited biofilm formation and eradicated biofilms, respectively. The oleoresins did not exert mutagenic effects and had superior food preservative action to sodium benzoate (positive control). In conclusion, Copaifera oleoresins exhibit potential antibacterial activity and are not mutagenic, which makes them a promising source to develop novel natural food preservatives to inhibit foodborne pathogens.