Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Synthesis and characterization of a natural-based hydrogel for biomedical applications(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-06-01) Ramírez Martínez, Carolina; Ramírez Martínez, Carolina; 0000-0003-2627-159X; Medina Medina, Dora Iliana; puelquio/mscuervo; Moya Bencomo, Marcos David; School of Engineering and Sciences; Campus Estado de México; Valencia Lazcano, Anai AliciaRecently, the scientific community has shown great interest in the use and modification of natural polymers as biomaterials with biomedical applications. The above is because of their high potential as coatings, excellent biocompatibility, and high bioactivity. Thanks to their broad catalog of modifiable properties and their good integration with tissues, hydrogels are widely used as materials matrices to facilitate wound healing, implants, controlled drug release, and low friction surfaces. Nowadays, it is possible to perform highly technological emergency procedures that allow the prevalence of human life, such as endotracheal intubations. However, when performed for an extended period, complications such as a joint tear, and airway obstruction can occur due to friction derived from the characteristics of the materials used. This master’s thesis proposes the synthesis and characterization of a hydrogel derived from natural sources as lubricating and relatively low-friction materials for their potential incorporation as coating of endotracheal tubes. The crosslinking of these hydrogels was accomplished physically using keratin and polysaccharides such as agar-agar and carboxymethylcellulose and was evaluated their water absorption at different concentrations. The morphological characteristics and porous architecture of the hydrogels were determined using Scanning Electron Microscopy (SEM). Chemical characterization was carried out using Fourier transformed infrared spectroscopy (FTIR) which made it possible to identify the functional groups that allowed the absorption of water from this material. The absorption of water from this material was evaluated by obtaining swelling rates up to 36.1912. The experiments carried out allowed to classify the hydrogel as a super absorbent and highly biocompatible material. The friction coefficients obtained are considered low; however, more research is needed to improve the lubrication of these surfaces. It was demonstrated that the implementation of interpenetrated networks increases the complexity of the properties of the hydrogel.
- Toxicological evaluation of the TiO2 anatase and rutile crystalline phases in H9c2 cardiac cells(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-05) Santos Aguilar, Pamela; CONTRERAS TORRES, FLAVIO FERNANDO; 132171; Contreras Torres, Flavio Fernando; emipsanchez; Lozano García, Omar; Silva Platas, Christian Iván; Salas Treviño, Daniel; School of Engineering and Sciences; Campus Monterrey; García Rivas, Gerardo de JesúsAlthough TiO2 particles constitute a highly used material in consumer products, including food and pharmaceutical industries, considerable experimental evidence suggests that TiO2 particle exposure could be harmful and cause adverse health effects. Generally, the most studied factor for toxicity is size as nano, and fine particles are considered more toxic than bulk forms. The second structural factor most studied is the crystalline phase. The TiO2 rutile phase is considered a more inert phase than the highly active, high-refractive-index anatase phase. The cytotoxicity of TiO2-anatase has been related to that these particles can induce higher production of reactive oxygen species (ROS), which is a trigger of apoptosis pathway and alteration of mitochondrial membrane potential in cells. However, such a toxicological susceptibility to the TiO2-anatase phase may differ from the one initiated by the TiO2-rutile phase, suggesting a different cell death mechanism, which is not known at the detail. In this thesis, a series of experimental measurements were carried out to analyze TiO2-anatase and TiO2-rutile submicron-sized particles' physical properties. The TiO2 particles in anatase phase were transformed to rutile phase through a heating process, and then both were analyzed by Raman spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS), and zeta potential. The evaluation of the toxicity of TiO2 particles in H9c2 cardiac cells to identify the role of the crystalline phase that may pose a health risk in a dose-dependent manner is the main objective of this study. The TiO2-anatase and TiO2-rutile particles' toxicity assessment was conducted in vitro, evaluating the metabolic activity, the plasma membrane integrity, mitochondrial superoxide production, and intracellular redox state. The particles' characterization by XRD and Raman spectroscopy confirmed the successful transformation of anatase particles to the rutile phase through a heating process. By DLS, it was confirmed that the hydrodynamic particle diameter was 166 nm and 468 nm for anatase and rutile, respectively. At the same time, further analysis by XLPA methods: Williamson-Hall and Warren Averbach showed that the apparent crystallite size of anatase is larger than for rutile. SEM microscopy identified that anatase particles had a spheric-like shape while for rutile were slightly more elongated. H9c2 cells show metabolic activity inhibition of 50% at an approximate value of 30 μg/mL when exposed to either anatase or rutile particles for 24 h. However, the dose-dependent inhibition at lower or higher values of the IC50 is dependent on the crystalline structure. Neither anatase phase nor rutile phase reduces the number of viable cells through necrosis; however, cell death has been categorized as early or late apoptosis for both particles. No significant alteration of the intracellular redox state at any particle exposure concentration between 0.3 μg/mL – 30 μg/mL was observed. On the other hand, for anatase, a 3-fold increase in mitochondrial superoxide production at 30 μg/mL was found, indicating that the intrinsic mitochondrial apoptotic pathway might mediate the apoptosis. However, for rutile, there is no increase in mitochondrial ROS production, suggesting that the cell death mechanism is dependent on a different metabolic pathway independent of the mitochondria.
- Characterization of the cytotoxicity of graphene oxide and reduced graphene oxide in hypertrophic cardiomyocytes(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-06-15) Luna Figueroa, Estefanía; GARCIA RIVAS, GERARDO DE JESUS; 43362; García Rivas, Gerardo de Jesús; emipsanchez/puemcuervo; Castorena Torres, Fabiola; Aguirre Tostado, Francisco Servando; Lozano García, Omar; Escuela de Medicina y Ciencias de la Salud; Campus Monterrey; Contreras Torres, Flavio FernandoGraphene oxide (GO) and reduced graphene oxide (RGO) are carbon nanomaterials, which stand out for their industrial and biomedical use due to their extraordinary physicochemical properties. Nevertheless, possible health risks call into question the benefits derived from its use. In particular, our interest is focused on cardiovascular tissue. Accumulation of particles in the myocardium may be feasible in this type of tissue, a risk that is more severe in tissues with a predisposition to damage. Even at low concentrations of particles, the risk ratio indicates the possibility of cardiometabolic disorders. The present study analyzes the cytotoxicity of GO and RGO in healthy cardiomyoblasts and cardiomyoblasts with cellular damage, using a pathological model of angiotensin II-induced hypertrophy. From the results obtained, we proposed possible mechanisms of cellular damage.