Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551014
Pertenecen a esta colección Tesis y Trabajos de grado de los Doctorados correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Corneal endothelium produced by tissue engineering(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-14) Montalvo Parra, María Dolores; Zavala Arcos, Judith; tolmquevedo; Ortega Lara, Wendy; Brunck, Marion; Valdez García, Jorge E.; Merayo Llóves, Jesús; School of Engineering and Sciences; Campus Monterrey; Aguilar Yañez, José ManuelEngineered corneal endothelium (ECE) must assure cell morphology and physiology. To do so, a biocompatible, transparent, scaffold is the best option. The purpose of this thesis is to produce an ECE with a collagen scaffold and corneal endothelium cells (CECs) harvested in a two-phase system that resembles healthy corneal endothelium (CE) characteristics. Collagen based scaffolds were produced in two steps: 1) Gelification; ~2 µl/mm2 of collagen type I, HEPES solutions, and fetal bovine serum mixture per well were placed on a 12 well plate, 37°C, 5% CO2 for 2 hrs. 2) Vitrification in a Matryoshka System: sealed desiccation chamber with a saturated solution of K2CO3 was placed in an oven set to 40°C. Collagen gels were left inside for 37 days to decrease relative humidity up to 40%. Scaffolds were characterized with confocal microscopy, SEM and spectrophotometry. CECs were isolated from young New Zealand rabbits and from human donor corneas independently. Descement’s membrane was peeled from cornea, digested and, CECs obtained were cultured until confluence in proliferative media (OptiMEM I, FBS 8%, nerve growth factor 20 ng/ml, endothelial growth factor 5ng/ml, CaCl2 200 µg/ml, ascorbic acid 20 µg/ml, chondroitin sulfate 0.08%, antibiotic 1%). Passages 1-2 were carried out in resting media (OptiMEM I 8%FBS). At passage 3, ~24,000 CECs were planted onto 8 mm Ø CV membranes. The alternate use of Proliferative and Resting media conforms the two phase culture system. SEM and confocal microscopy tests showed CV membranes yielded a ~4 µm thickness and smooth surface upon 20 min hydration. SEM also showed collagen fibers merge to form a mesh-like laminar structure. Spectrophotometric scan from 450-700 nm showed a 94-95.5% transmittance. CECs seeded on CV membranes showed adhesion and proliferation at 24 hours; 72 hours served to reach confluence in a ~5 mm Ø. Culture on scaffolds reached canonical CE shape. We produced 12 rabbit and 5 human ECE with desired morphology and specific molecular marker expression. In conclusion, our collagen membrane synthesis method, along with the two phase CECs culture system, offers an option to produce ECE with healthy endothelium characteristics.
- Bioresorbable materials and additive manufacturing process for medical implants(Instituto Tecnológico y de Estudios Superiores de Monterrey) Tejeda Alejandre, Raquel; 368866; 368866; 368866; 368866; 368866; 368866; 368866; 368866; 368866; 368866; Rodríguez González, Ciro A.; Escuela de Ingeniería y Ciencias; Campus Monterrey; Dean, DavidThe application of additive manufacturing technologies in tissue engineering has been growing in recent years. Among different technology options, 3D printing is becoming popular due to the ability to directly print scaffolds with designed shape and has great potential like manufacturing method in the production of scaffolds for tissue engineering. Applications of additive manufacturing in regenerative medicine and tissue engineering are restricted for the available materials for each technology. A great part of the research has focused on the development of new materials to be used to create complex geometries, culture different kind of cells from a different types of tissues and applications. In this work, recent developed additive manufacturing techniques and biomaterials for vascular and bone tissue are studied. The objective of tissue engineering is to produce functional and viable structures and multiple biomaterials and fabrication methods need to be researched. To achieve this purpose, the fabrication of bifurcated vascular grafts using the combination of electrospinning and 3D printing, and the characterization of a new biomaterial for bone regeneration applications, were explored. Polycaprolactone (PCL) was used to electrospun a mandrel obtaining a bifurcated construct that was morphological and mechanical characterized. For bone regeneration applications, a new resorbable biomaterial was investigated. Process parameters and materials properties, such as separation force and green strength were studied in order to probe the printability of this material, compositional changes, or defects during the 3D printing process, of porous structures using Continuous Digital Light Processing (cDLP) and Isosorbide.