https://repositorio.ufba.br/handle/ri/20583 Mon, 04 May 2026 08:07:08 GMT 2026-05-04T08:07:08Z https://repositorio.ufba.br/handle/ri/43745 Título: Controle microbiano por fotoinativação em cepas bacterianas resistentes isoladas em trechos do rio Camarajipe Autor(es): Davi, Léda Gonçalves Primeiro Orientador: Santos, Gustavo Miranda Pires Abstract: Introduction: Camarajipe River belongs to one of the most polluted watersheds in Salvador, having been degraded due to the lack of sanitation and the illegal discharge of contaminated effluents. These metropolitan rivers are often populated by multidrug-resistant microorganisms. Microbial resistance is a growing concern for public health, especially in densely populated urban areas where antibiotic contamination can promote the emergence of multidrug-resistant strains. This dissertation explores photoinactivation, an alternative technique for microbial control that uses light and a photosensitizing molecule as a possible solution to combat these strains without promoting additional resistance. Objective: The main objective of the study was to investigate the effectiveness of photoinactivation against resistant bacterial strains isolated from the Camarajipe River. Additionally, the study explored the potential synergy between photoinactivation and the use of high-frequency equipment to amplify antimicrobial effects. Methods: This study involved the collection of water samples from different points along the Camarajipe River to isolate multidrug-resistant Pseudomonas spp. strains. After identifying the strains, photoinactivation experiments were conducted using Methylene Blue as a photosensitizer and a red LED light device. High-frequency current experiments were also conducted to evaluate its bactericidal capacity, both in isolation and in combination with photoinactivation. Results: Photoinactivation proved to be effective against multidrug-resistant strains, with significant inhibition observed in bacterial cultures when an appropriate concentration of Methylene Blue was used. The application of high-frequency currents also demonstrated bactericidal efficacy but only when applied before the addition of the photosensitizer, when the therapy was conducted in liquid media, showing significant effect alone when done in solid media. The combination of the two techniques showed promising results, suggesting that the use of high-frequency currents can enhance the effects of photoinactivation. This study highlights the relevance of alternative methods, such as photoinactivation combined with high frequency, in combating infections caused by resistant strains, offering a potential pathway to reduce the dependence on antibiotics in the treatment of bacterial infections. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação Thu, 26 Sep 2024 00:00:00 GMT https://repositorio.ufba.br/handle/ri/43745 2024-09-26T00:00:00Z https://repositorio.ufba.br/handle/ri/43571 Título: Do perfil químico à inovação cosmética: potencial antioxidante e antimicrobiano do óleo essencial de Cymbopogon densiflorus Autor(es): Sabino, Atílio Araújo Primeiro Orientador: Vale, Ademir Evangelista do Abstract: This study aimed to characterize the chemical profile, evaluate the antioxidant and antimicrobial potential of Cymbopogon densiflorus essential oil, and develop and analyze a topical cosmetic formulation incorporating the oil. The plant material was collected in the North-Central region of Bahia, and the essential oil was obtained by hydrodistillation in a Clevenger apparatus. Chemical characterization was performed by gas chromatography-mass spectrometry (GC-MS), complemented by molecular network analysis using the GNPS platform. The antioxidant evaluation was conducted by the DPPH• radical method, while the antimicrobial activity was determined by the disk diffusion and broth microdilution methods, against the strains Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. The GC-MS analysis revealed eleven major constituents, representing 40.7% of the total composition, with a predominance of oxygenated monoterpenes, highlighting Trans-isopulegol (18.9%), Cis-p-mentha-1(7),8-dien-2-ol (16.9%), Trans-p-mentha-1(7),8-dien-2-ol (15.0%) and D-limonene (14.0%). The essential oil showed dose-dependent antioxidant activity, reaching 10.4% inhibition of the DPPH• radical at a concentration of 80 mg/mL. In antimicrobial tests, significant activity was observed against S. aureus, with mean inhibition zones of 14.3 ± 0.5 mm, and a moderate effect against E. coli, with a zone of 9.8 ± 0.6 mm, in addition to a Minimum Inhibitory Concentration (MIC) of 400 µg/mL for the pure oil. The nonionic cream cosmetic formulation containing 10% essential oil demonstrated good physical and organoleptic stability over 30 days, maintaining a stable pH and the absence of phase separation. The product also demonstrated antimicrobial activity against S. aureus and E. coli, suggesting potential application as an active agent in natural dermocosmetic formulations. The results obtained confirm the biotechnological potential of Cymbopogon densiflorus essential oil, indicating it as a promising source of bioactive compounds with antioxidant and antimicrobial properties, suitable for application in the cosmetic, pharmaceutical and herbal medicine industries. Editora / Evento / Instituição: UNIVERSIDADE FEDERAL DA BAHIA Tipo: Dissertação Mon, 27 Oct 2025 00:00:00 GMT https://repositorio.ufba.br/handle/ri/43571 2025-10-27T00:00:00Z https://repositorio.ufba.br/handle/ri/42803 Título: A importância da biocerâmica porosa de β-fosfato tricálcico (β-TCP) na reparação e regeneração óssea da osteonecrose da cabeça femoral. Autor(es): Azevedo, Adler Lima Botelho de Primeiro Orientador: Silva, Antonio Ferreira da Abstract: This study aims to analyze the interaction between osteoconductive ceramic and osteoinductive stem cells in the repair and regeneration process of femoral head osteonecrosis in individuals with sickle cell disease and its biofunctionality. The clinical study explores an innovative approach to treating avascular necrosis of the femoral head (ONFH) in patients with sickle cell disease. The treatment involves combining bioceramic material with bone marrow-derived mononuclear cells. A total of 24 patients with ONFH at Ficat stages I and II due to sickle cell disease were included in the study. Surgical procedures involved the insertion of a 3 mm wire to guide the surgery, followed by central decompression, bone marrow collection containing mesenchymal stem cells, and grafting of porous granules mixed with autologous bone marrow. Six months post-surgery, osteointegration of the bioceramic material was observed, with the sphericity of the femoral head maintained. Most patients remained stable and pain-free after the treatment. The study suggests that combining bone marrow-derived mononuclear cells and bioceramic material may be effective in preventing the progression of ONFH in patients with sickle cell disease. The clinical, functional, and imaging results of this study indicate successful restoration, regeneration, and function of the femoral head. This led to improved hip functionality, increased mobility, and stability in walking. Further research and larger studies are needed to confirm these promising results and to verify the effectiveness of this treatment approach. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação Fri, 18 Oct 2024 00:00:00 GMT https://repositorio.ufba.br/handle/ri/42803 2024-10-18T00:00:00Z https://repositorio.ufba.br/handle/ri/42749 Título: Potencialidades Cosmecêuticas e Biotecnológicas dos Extratos Vegetais de Hancornia speciosa Gomes: Fitoquímica, Fotoproteção e Metabolômica Baseada em Espectrometria de Massas e Impressão Digital Química Autor(es): Silva, Robson Almeida Primeiro Orientador: Vale, Ademir Evangelista do Abstract: The phytochemical study of plant species from the semi-arid and Recôncavo regions of Bahia has shown the presence of metabolites with relevant pharmacognostic and biotechnological properties. In a scenario of growing demand for sustainable solutions, the application of plant active ingredients in natural photoprotectors becomes a potential alternative. Hancornia speciosa Gomes has high antioxidant potential, although its use as a photoprotective agent remains incipient. This study investigated the chemical profile of extracts and fractions from the leaves and stem of the species using high-resolution mass spectrometry (UHPLC-HRMS), with subsequent analysis by molecular networks (Feature-based Molecular Networking - GNPS), and evaluated their antioxidant and photoprotective properties. A technological mapping was also conducted (via the PRISMA protocol) that showed the growth of innovations related to antioxidants and natural photoprotectors, although with limited Brazilian participation. The extracts were subjected to in vitro antioxidant tests (DPPH·, FRAP, total phenolic content and beta-carotene degradation), as well as determination of the sun protection factor (SPF) by the Mansur method. Additionally, a factorial design (33-1) was applied to optimize cosmeceutical formulations based on the extracts. The results indicated that the ethanolic extract of the stem (EETC) showed the best antioxidant performance (95.48±1.36% in DPPH·) and the highest reducing capacity in FRAP (45,008±858.30 µM FeSO₄/g). Metabolomic analysis revealed 56 putatively annotated compounds, distributed in 334 clusters and 3,481 nodes, highlighting glycosylated flavonoids, iridoids, pyrrolizidine alkaloids, carbohydrates and amino acids. A correlation was observed between the structure of glycosylated flavonoids and their antioxidant activity. In the antimicrobial screening, EETF inhibited Bacillus cereus (78.44±2.63%) and EETC was more effective against Candida auris (57.24±3.37%), with lower toxicity against Artemia salina. The optimized formulation with EETC obtained SPF higher than 44, demonstrating its high potential for cosmeceutical applications. Therefore, H. speciosa proves to be a promising source of bioactive metabolites, with prospects for the development of natural photoprotectors of high biotechnological value, reinforcing the importance of future studies, especially with the application of nanotechnologies. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Dissertação Mon, 14 Jul 2025 00:00:00 GMT https://repositorio.ufba.br/handle/ri/42749 2025-07-14T00:00:00Z