Ciencias de la Salud

URI permanente para esta comunidadhttps://hdl.handle.net/11441/10983

Examinar

Mostrando 1 - 4 de 4

Fe₃ O₄-Au Core-Shell Nanoparticles as a Multimodal Platform for in Vivo Imaging and Focused Photothermal Therapy
(MDPI, 2021-03) Caro Salazar, Carlos; Gámez Márquez, Francisco; Quaresma, Pedro; Páez-Muñoz, José María; Domínguez Moreno, Alejandro; Pearson, John R.; Pernia Leal, Manuel; Beltrán, Ana M.; Fernandez-Afonso, Yilian; Fuente, Jesús M. de la; Franco, Ricardo; Pereira, Eulália; García-Martín, María Luisa; Universidad de Sevilla. Departamento de Química Orgánica y Farmacéutica; Universidad de Sevilla. Departamento de Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla. FQM102: Estereoquímica y Síntesis Asimétrica; Universidad de Sevilla. TEP123: Metalurgia e Ingeniería de los Materiales
In this study, we report the synthesis of gold-coated iron oxide nanoparticles capped with polyvinylpyrrolidone (Fe@Au NPs). The as-synthesized nanoparticles (NPs) exhibited good stability in aqueous media and excellent features as contrast agents (CA) for both magnetic resonance imaging (MRI) and X-ray computed tomography (CT). Additionally, due to the presence of the local surface plasmon resonances of gold, the NPs showed exploitable “light-to-heat” conversion ability in the near-infrared (NIR) region, a key attribute for effective photothermal therapies (PTT). In vitro experiments revealed biocompatibility as well as excellent efficiency in killing glioblastoma cells via PTT. The in vivo nontoxicity of the NPs was demonstrated using zebrafish embryos as an intermediate step between cells and rodent models. To warrant that an effective therapeutic dose was achieved inside the tumor, both intratumoral and intravenous routes were screened in rodent models by MRI and CT. The pharmacokinetics and biodistribution confirmed the multimodal imaging CA capabilities of the Fe@AuNPs and revealed constraints of the intravenous route for tumor targeting, dictating intratumoral administration for therapeutic applications. Finally, Fe@Au NPs were successfully used for an in vivo proof of concept of imaging-guided focused PTT against glioblastoma multiforme in a mouse model.
Influence of Femtosecond Laser Modification on Biomechanical and Biofunctional Behavior of Porous Titanium Substrates
(MDPI, 2022-04) Beltrán, Ana M.; Giner García, Mercedes; Rodríguez Carballo, Ángel; Trueba Muñoz, Paloma; Rodríguez-Albelo, Luisa Marleny; Vázquez Gámez, María de los Ángeles; Fortio Godinho, Vanda Cristina; Alcudia Cruz, Ana; Amado Paz, José Manuel; López Santos, Carmen; Universidad de Sevilla. Departamento de Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla. Departamento de Citología e Histología Normal y Patológica; Universidad de Sevilla. Departamento de Medicina; Universidad de Sevilla. Departamento de Química Orgánica y Farmacéutica; Universidad de Sevilla. Departamento de Física Aplicada I; Universidad de Sevilla. TEP123: Metalurgia e Ingeniería de los Materiales; Universidad de Sevilla. CTS211: Metabolismo Cálcico, Hipertensión y Arteriosclerosis; Universidad de Sevilla. FQM135: Carbohidratos y Polímeros; Universidad de Sevilla. FQM196: Nanotecnología en Superficies y Plasma
Bone resorption and inadequate osseointegration are considered the main problems of titanium implants. In this investigation, the texture and surface roughness of porous titanium samples obtained by the space holder technique were modified with a femtosecond Yb-doped fiber laser. Different percentages of porosity (30, 40, 50, and 60 vol.%) and particle range size (100–200 and 355–500 μm) were compared with fully-dense samples obtained by conventional powder metallurgy. After femtosecond laser treatment the formation of a rough surface with micro-columns and micro-holes occurred for all the studied substrates. The surface was covered by ripples over the micro-metric structures. This work evaluates both the influence of the macro-pores inherent to the spacer particles, as well as the micro-columns and the texture generated with the laser, on the wettability of the surface, the cell behavior (adhesion and proliferation of osteoblasts), micro-hardness (instrumented micro-indentation test, P–h curves) and scratch resistance. The titanium sample with 30 vol.% and a pore range size of 100–200 μm was the best candidate for the replacement of small damaged cortical bone tissues, based on its better biomechanical (stiffness and yield strength) and biofunctional balance (bone in-growth and in vitro osseointegration).
Limits of powder metallurgy to fabricate porous Ti35Nb7Zr5Ta samples for cortical bone replacements
(Elsevier, 2023-06) Rodríguez-Albelo, Luisa Marleny; Navarro González, Paula; Gotor Martínez, Francisco José; Rosa Melián, Julio Ernesto de la; Mena Torres, Danaysi; García-García, Francisco J.; Beltrán, Ana M.; Alcudia Cruz, Ana; Torres Hernández, Yadir; Universidad de Sevilla. Departamento de Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla. Departamento de Química Orgánica y Farmacéutica; MCIN/AEI/10.13039/501100011033/and Junta de Andalucía PID2019-109371 GBI00; Universidad de Sevilla. FQM408: Química Farmacéutica Aplicada; Universidad de Sevilla. TEP123: Metalurgia e Ingeniería de los Materiales
The use of β-Titanium alloys to fabricate metal implants with Young's modulus that resembles bone tissues is presented as an alternative to commercially pure titanium or α-Titanium alloys, although it is still necessary to introduce proper implant porosity to reach the Young's modulus of cortical bones. In this work, porous samples were fabricated by loose sintering (0 MPa) and compared to samples manufactured at 1000 MPa, both sintered under the same conditions. Raw powders and sintered samples of the β-Titanium alloy, Ti35Nb7Zr5Ta, were characterized in detail in terms of both physicochemical and microstructural properties. Moreover, the tribo-mechanical behavior of sintered samples was evaluated by performing ultrasound technique, instrumented micro-indentation (P-h curves), and scratch tests. The bio-functional behavior was studied by impedance spectroscopy and contact angle measurements. The results allowed the evaluation of the limits of conventional powder metallurgy (percentage of porosity, size, and morphology of pores), as well as the influence of the porosity and chemical composition to achieve a better biomechanical and bio-functional behavior that would guarantee bone requirements. The Ti35Nb7Zr5Ta alloy showed relatively high electrical impedance values compared to commercially pure titanium, indicating an improved bio-corrosion behavior. Furthermore, wettability measurements indicated that porous disks fabricated by loose sintering exhibit higher hydrophilicity, often associated with a better antibacterial response.
Use of Impedance Spectroscopy for the Characterization of In-Vitro Osteoblast Cell Response in Porous Titanium Bone Implants
(MDPI, 2020-08) Giner García, Mercedes; Olmo Fernández, Alberto; Hernández, Miguel; Trueba Muñoz, Paloma; Chicardi Augusto, Ernesto; Civantos, Ana; Vázquez Gámez, María de los Ángeles; Montoya García, María José; Torres Hernández, Yadir; Universidad de Sevilla. Departamento de Citología e Histología Normal y Patológica; Universidad de Sevilla. Departamento de Tecnología Electrónica; Universidad de Sevilla. Departamento de Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla. Departamento de Medicina; Universidad de Sevilla. CTS211: Metabolismo Cálcico, Hipertensión y Arteriosclerosis; Universidad de Sevilla. TIC178: Diseño y Test de Circuitos Integrados de Señal Mixta; Universidad de Sevilla. TEP123: Metalurgia e Ingeniería de los Materiales; Universidad de Sevilla. TEP973: Tecnología de Polvos y Corrosión
The use of titanium implants with adequate porosity (content, size and morphology) could solve the stress shielding limitations that occur in conventional titanium implants. Experiments to assess the cellular response (adhesion, proliferation and differentiation of osteoblasts) on implants are expensive, time-consuming and delicate. In this work, we propose the use of impedance spectroscopy to evaluate the growth of osteoblasts on porous titanium implants. Osteoblasts cells were cultured on fully-dense and 40 vol.% porous discs with two ranges of pore size (100–200 μm and 355–500 μm) to study cell viability, proliferation, differentiation (Alkaline phosphatase activity) and cell morphology. The porous substrates 40 vol.% (100–200 µm) showed improved osseointegration response as achieved more than 80% of cell viability and higher levels of Cell Differentiation by Alkaline Phosphatase (ALP) at 21 days. This cell behavior was further evaluated observing an increase in the impedance modulus for all study conditions when cells were attached. However, impedance levels were higher on fully-dense due to its surface properties (flat surface) than porous substrates (flat and pore walls). Surface parameters play an important role on the global measured impedance. Impedance is useful for characterizing cell cultures in different sample types.

Examinar

Examinando Ciencias de la Salud por Premio "Premio Mensual Publicación Científica Destacada de la US. Escuela Politécnica Superior"