Browsing by Author "Bermeo Acosta, Franklin (Director)"
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Item Efecto bactericida de recubrimientos de plata/ TiO2 /TiO2-Ag/TiN frente a Staphylococcus aureus en implantes biomédicos(Universidad Santiago de Cali, 2024) Cubides Arango, Danna Marcela; Gómez Chaux, Lix Letxi; Bermeo Acosta, Franklin (Director); Bonilla Suarez, Rafael Antonio (Director)The use of permanent medical devices has been of great interest and increase in recent years due to the improvement in the quality of life of patients affected by different diseases, however, although hospital hygiene conditions are controlled, infections associated with implants are still a common and serious complication that can lead to implant failure. Staphylococcus aureus is one of the most common pathogens of infection in implants, since by binding to the medical device these bacteria develop dense communities enclosed in a protective matrix called biofilm. Addressing this problem, this research work studied the interaction of S. aureus with Tiox, Tiox/Ag, Ti360/Ag, Ti810/Ag, TiN films, each one with different morphologies, materials and concentrations in order to demonstrate which of these biomaterials have bacteriostatic or bactericidal activity. All films showed bacterial inhibition, the highest percentage of inhibition being Ti360/Ag (85%) and Tiox/Ag (82%). These films were characterized structurally (XRD), morphologically (SEM), roughness with profilometry and AFM.Item Estudio de películas de titanio-plata aplicaciones protectoras en dispositivos biomédicos(Universidad Santiago de Cali, 2021) Mina Aponza, Sebastián; Castro Narváez, Sandra Patricia (Directora); Bermeo Acosta, Franklin (Director)The search for coatings that prolong the useful lifetime of biomedical devices has been of interest, titanium being of great relevance due to its innocuousness and low reactivity. This study contributes to the investigation of Ti/Ag films in different configurations (mono and multilayer), deposited by magnetron sputtering. The sessile drop technique is implemented to study wettability, obtaining greater penetrability of the films where Ag is arranged as an external layer, confirming high efficiency in cell adhesion. The morphological properties were characterized by SEM, showing porous nuclei on the surface in the Ag coating and crystals embedded in the Ti film. The structural properties were studied by XRD revealing the presence of TiO2 in the crystalline phase of anatase in a proportion of 49.9% and silver forming a cubic lattice centered on the faces. Tafel polarization curves demonstrate improvements in Ag/Ti/Ag/Ti/Ag/Ti and Ti/Ag corrosion current densities versus Ag coating with 0.1749, 0.4802 and 2.044 nA*cm-2 respectively. The antimicrobial activity was evaluated against Pseudomonas aeruginosa bacteria, Bacillus subtilus and the yeasts Candida krusei, Candida albicans reveal that Ti/Ag and Ag/Ti/Ag/Ti/Ag/Ti coatings exhibit promising applications as biomedical material.Item Estudio morfológico, estructural y microbiológico de películas delgadas de Ti-Ag para implantes coronarios(Universidad Santiago de Cali, 2024) Nañez Varela, Jhon Eivar; Guerrero Rosero, Valentina; Bermeo Acosta, Franklin (Director); Castro Narváez, Sandra Patricia (Directora)Coronary implants are medical devices designed to improve blood flow to the heart and are used in the treatment of diseases such as coronary arteriosclerosis, myocardial infarction and angina pectoris. In this context, new materials, such as titanium and silver, are being investigated because of their biocompatibility properties and antimicrobial capacity. The present study aims to determine the optimal ratio of titanium and silver in thin films used in coronary implants to maximize their antimicrobial efficacy. For this purpose, Ti-Ag thin films were fabricated using the DC sputtering technique, which were structurally and morphologically characterized. Furthermore, their antimicrobial activity against Gram-positive bacteria, such as Staphylococcus aureus and Enterococcus faecalis, and a filamentous fungus Aspergillus niger was evaluated. The coating was found to significantly influence the doubling time of these microorganisms. Among the coatings studied, the Ti/Ag 90/90 ratio coating showed the best antimicrobial capacity, effectively inhibiting both E. faecalis and S. aureus.Item Optimización de procesos cuantitativos y cualitativos de fluidez para polímeros plásticos en la empresa Gonzales Arango Daniplas(Universidad Santiago de Cali, 2024) Torres Panameño, Keynes Johan; Bermeo Acosta, Franklin (Director)The search for polymer blends has grown significantly in various areas, such as medicine, chemistry and biology, due to their applications in the development of materials with specific properties. These mixtures, also known as polymer alloys or composites, combine different types of polymers in order to obtain materials with characteristics that could not be achieved with a single polymer. . Virgin polymers are lightweight materials, with high chemical resistance and flexibility even at low temperatures, which makes them suitable for various applications, but their exclusive use is neither sustainable nor economical due to the high production cost and dependence on non-renewable resources. . On the other hand, recycled polymers have limitations such as low impact resistance at low temperatures and susceptibility to thermal degradation, but their use is more economical and sustainable, which makes them attractive from an environmental point of view. The combination of these two types of polymers seeks to create materials that are not only cost-effective and environmentally friendly, but also have acceptable technical performance. The approach was based on combining virgin and recycled polymers by using a mathematical model, such as the Boltzmann logistic distribution, to predict the optimal composition point.