http://bdtd.uftm.edu.br/handle/tede/701 2026-11-06T16:09:51Z 2026-11-06T16:09:51Z http://bdtd.uftm.edu.br/handle/123456789/2184 2026-11-05T02:03:00Z 2026-09-01T00:00:00Z

Título: Biovidros ativos multifuncionais dopados com prata e európio para aplicações biomédicas: caracterização, atividade antibacteriana, citocompatibilidade e potencial regenerativo Abstract: Nanostructured bioactive glasses have emerged as promising biomaterials for bone repair, particularly when functionalized with ions capable of providing antimicrobial properties. This study aimed to evaluate the biological performance of bioactive glasses doped with silver and europium through physicochemical characterization, in vitro assays, and in vivo evaluation in an experimental model. Structural characterization confirmed the formation of a typical SiO₂– Na₂O–CaO–P₂O₅ glass network, with structural modifications associated with silver incorporation. In vitro results demonstrated that silver-containing formulations exhibited concentration-dependent antibacterial and antibiofilm activity against Staphylococcus aureus, Escherichia coli, and Streptococcus mutans, while maintaining high cytocompatibility in Vero cells. Europium incorporation did not significantly influence the evaluated biological parameters. Based on these findings, formulations containing 0.5 wt% and 1.25 wt% silver were selected for in vivo evaluation in a rat calvarial defect model. The results showed that silver concentration directly modulated tissue response, with 0.5 wt% promoting a more pronounced initial inflammatory response, whereas 1.25 wt% was associated with increased collagen deposition and extracellular matrix maturation. In conclusion, silver doping confers multifunctional properties to bioactive glasses, highlighting their potential for bone tissue engineering applications. The dopant concentration plays a critical role in balancing antimicrobial efficacy and biological response. Tipo: Tese

2026-09-01T00:00:00Z http://bdtd.uftm.edu.br/handle/123456789/2149 2026-09-22T02:03:15Z 2025-10-07T00:00:00Z

Título: Atividade antifúngica in vitro e in vivo de cristais de tungstato de prata ( Ag2WO4 ) contra Candida albicans. Abstract: Candida albicans remains the most prevalent cause of invasive candidiasis and is recognized as a critical priority fungal pathogen given its global clinical burden, high mortality rates, and rising antifungal resistance. Here, we investigated the antifungal activity of α-Ag₂WO₄ microcrystals against C. albicans in vitro and in vivo. The crystals exhibited strong activity, with low MIC (3,125 μg mL⁻¹) and fungicidal effect (6,25 μg mL⁻¹). They markedly suppressed the yeast–hypha transition, even at sub-inhibitory concentrations, and inhibited biofilm formation in a concentration-dependent manner. Pre-treatment of abiotic surfaces with α-Ag₂WO₄ effectively prevented fungal adhesion and biofilm maturation, with complete inhibition achieved at 10 mg mL⁻¹. However, no synergistic effect with fluconazole was detected, and in vivo analysis using Galleria mellonella showed limited efficacy, as treatment failed to protect larvae from C. albicans infection despite low toxicity. These findings highlight that while α-Ag₂WO₄ crystals may have restricted potential as systemic antifungal agents, they represent a promising strategy to prevent device-associated infections by targeting adhesion and biofilm development on abiotic surfaces. Tipo: Dissertação

2025-10-07T00:00:00Z http://bdtd.uftm.edu.br/handle/123456789/2074 2026-01-27T02:02:52Z 2024-10-29T00:00:00Z

Título: Desenvolvimento de um imunossensor eletroquímico pioneiro para detecção precisa da leishmaniose visceral humana com antigeno recombinante purificado de leishmania Abstract: Leishmaniasis is a disease that affects a large part of the population of Latin America, especially in Brazil. It has a high mortality rate if left untreated. The main diagnostic methods currently used are based on signs and symptoms suggestive associated with parasitological and/or immunological tests, however, such tests have disadvantages such as low sensitivity and specificity, high cost, need for equipped laboratories and qualified professionals. Thus, it is necessary to have a fast, accurate, low-cost, portable diagnosis that has good sensitivity and specificity. In this study, a recombinant antigen called DTL-4 was used because of its potential to improve the sensitivity and specificity of the tests because it only allows specific binding with the antibody in the serum of patients with the disease. The results of the proposed immunosensor showed an estimated detection limit of 0.0442 ng mL−1. The absence of modifications with gold nanoparticles is another interesting point when we compare the cost related to the biosensor in question with other diagnostic methods. Thus, the proposed immunosensor has low cost, high specificity and sensitivity. In this way, the biosensor in question shows promise for validating the diagnostic platform and its future portable use in public health. Tipo: Dissertação

2024-10-29T00:00:00Z http://bdtd.uftm.edu.br/handle/123456789/2067 2026-09-23T16:24:31Z 2019-05-25T00:00:00Z

Título: Desenvolvimento de imunossensor para detecção específica de Leishmanioses em eletrodo de grafite com ouro eletrodepositado Abstract: This work describes the methodology for electrochemical diagnosis of Leishmaniasis (LSH), it suppresses cross-reaction of Chagas disease (DC). Cross-reactions happen in commercially available (ELISA) tests and thus do not allow correct beginning and / or early treatment. Knowing the sensitivity of the sensor, total antigens tested in the ELISA were methodologically appropriate to the sensor. There were used 3 kinds of screen-printed electrodes: gold, graphite and graphite with electrodeposited gold film to observe biomolecular interaction in the work’s electrode and recognizing the samples. Antibodies present in serum from patients with diverse types of Chagas' Disease and Leishmaniases were chosen. The electrochemical analyses took place from the redox analysis of Ferri solution/Potassium ferrocyanide. The results showed that the graphite electrode with gold electrodeposited film guaranteed effective adsorption of the total antigens so that the epitope of specific recognition for Leishmaniasis occurred efficiently and without cross-reaction with the evaluated Chagas disease. The oxidation current peaks reduced linearly after the recognition, and still being able to notice the discrimination between kinds of diseases. Pool of sera or specific kinds (digestive, cardiac, undetermined Chagas / Acute and chronic Leishmaniasis) presented remarkable discrimination in the immunosensor. Comparative analyses with indirect ELISA were performed with the same groups, presenting cross reactions. Furthermore, the sensor presented relative stability within 5 days. Thus, we presented an innovative proposal of an immunosensor that suppressed the cross reaction to Chagas disease for specific detection of Leishmaniasis. Tipo: Dissertação

2019-05-25T00:00:00Z