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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- PEGylation of Silk Fibroin Nanoparticles for the Encapsulation of 3,3’-diindolylmethane in Route for the Treatment of Obesity(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025) Escobar Fernández, Aleyda Margarita; Mayolo Deloisa, Karla Patricia; emimmayorquin; Lozano García, Omar; Benavides Lozano, Jorge Alejandro; Morales Martínez, Adriana; School of Engineering and Sciences; Campus Monterrey; Sánchez Trasviña, CalefObesity is responsible for 5 million deaths each year. Considering the complexity of the disease, alternative plant-based compounds, like 3,3´-diindolylmethane (DIM), have become of therapeutical interest. To overcome the poor bioavailability of DIM and enhance its delivery, silk fibroin nanoparticles (SFNP) can be employed. The aim of this work was to PEGylate DIM-loaded SFNP using 5 kDa p-nitrophenyl carbonate methoxy polyethylene glycol (mPEG-PNC), to reduce the previously reported cytotoxicity of SFNP. First, the optimal PEGylation conditions were determined by chromatographic, electrophoretic and computational methods. Silk fibroin (SF) showed higher flexibility, group availability and reactivity when using sodium borate buffer at pH 9.4, thus PEGylation was enhanced. These findings were applied on the PEGylation of SF and SFNP at different mass ratios with mPEG-PNC. After this analysis, PEGylation of DIM-loaded SFNP was performed under a mPEG:SFNP mass ratio of 6:1, achieving a PEGylation efficiency of 11.9 ± 7.79 %. These particles had a spherical shape with a size of 98.98 ± 1.97 nm, a surface charge of -30.86 ± 1.09 mV, and a polydispersity index of 0.18. The encapsulation efficiency of DIM in SFNP was 13.16 ± 4.74%, exceeding previous reports. Drug release analysis in physiological conditions suggests that PEGylation prolongued DIM liberation, even after 48 h. Finally, it was confirmed that PEGylated SFNP reduced cytotoxicity on 3T3-L1 preadipocytes, maintaining a 100% cell viability at all evaluated doses, unlike unmodified SFNP. These results demonstrate that PEGylated SFNP, under the developed methodology, can become a promising vehicle to enhance the delivery of DIM, for the treatment of obesity.
- Design of droplet-based microfluidic devices and its application for protein fractionation(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-04) Hernández Cid, David; Mata Gómez, Marco Arnulfo; qro /|bqrotbecerra/tolmquevedo; Pérez González, Victor Hugo; Cervantes Avilés, Pabel Antonio; School of Engineering and Science; Campus Monterrey; González Valdéz, José GuillermoMicrofluidics technology offers new possibilities due to the nature of small scale, such as the high surface area to volume ratio. Droplet based microfluidics is an emerging field that has found its application in different areas, like material science, chemical reactions, and biochemical analysis. On the other hand, downstream processing operations like separation and purification still has some drawbacks like big reagents consumption, huge waste generation, extra steps like concentration or salts removal. Here is where microfluidics can be implemented to overcome some of the issues presented in this field. In this work, we designed and developed a microfluidic platform able to generate droplet-like aqueous two- phases system (ATPS) in a continuous manner. We started this project by performing a study of how different forces like surface tension, inertial forces, viscous forces, and geometry affect droplet formation. We found that all the previously mentioned parameters have an impact in different ways on the process of droplet formation. Afterwards, this knowledge was used to implement a microfluidic flow-focusing on the generation of droplet-based micro ATPS with the used of salts and PEG as the two liquid phases of the ATPS. To see that this ATPS droplet microfluidic system really worked, we tested its capacity to fractionate ribonuclease A (RNase A) on its native and PEGylated forms, which have affinity for the salt and PEG phases, respectively. Thus, we expected that proteins would get inside or outside droplets or streamlines according to their affinity for each of the two phases. In doing so, native, and PEGylated proteins were labeled with FITC and their movement from one to another phase or their retention in the phase where protein was placed were recorded. It was confirmed that proteins move or keep in their phase for which they have more affinity. This result opens the possibility for the development of microfluidic separators based on ATPS droplet formation.
- Immunoaffinity aqueous two-phase systems to establish novel bioprocesses for the primary recovery of CD133+ stem cells(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-25) Ornelas González, Alonso; Rito Palomares, Marco Antonio; Zavala Arcos, Judith; González González, Mirna Alejandra; Rito Palomares, Marco Antonio; Zavala Arcos, Judith; González González, Mirna AlejandraA short processing time and efficient scale-up stem cell isolation bioprocess is essential to exploit the potential of these cells for the treatment of multiple chronic diseases. Various methodologies have been used for stem cell recovery, however, most of them present economical and/or time-consuming drawbacks. In this work, the characterization and optimization of immunoaffinity aqueous two-phase systems, a liquid-liquid based separation technology enhanced with the PEGylation of the antibody, was conducted with the aim of increasing the specificity for the recovery of CD133+ stem cells from human umbilical cord blood samples. The methodology consisted in evaluating the partitioning of the different PEGylated antibodies (amine, carboxyl, thiol, succinimidyl ester, methoxy PEG and maleimide) in three previously studied aqueous two-phase systems (ATPS); PEG-dextran (DEX), Ucon-DEX and Ficoll-DEX. Subsequently, an optimization step was accomplished to manipulate the partition behavior of the CD133/2-pure antibody to the desired phase in the selected systems by varying (increasing and decreasing) two parameters closely related with the partitioning of molecules in aqueous two-phase systems; tie-line length (TLL) and volume ratio (VR). Afterwards, the partitioning behavior of the six different PEGylated antibodies in the optimized systems was tested. According to the results, the PEGylation of the CD133/2-biotin antibody induced a favorable change with respect to the non-PEGylated one when Ucon-DEX system was used, fractionating it to both phases. Likewise, the optimization of the systems showed to be effective to induce a change in the partition preference of the antibody. The best results were obtained when Ucon-DEX or PEG-DEX systems with TLL 15% w/w or 20% w/w with VR 3 were combined. Finally, PEGylated antibodies were added to the selected optimized systems. Even though a shift in the fractionation preference of the PEGylated CD133/2-biotin antibody was achieved in the optimized systems, it was not the adequate partition to justify the evaluation of this immunoaffinity ATPS with human umbilical cord samples. Both PEGylation and optimization showed to be effective to induce a change in the partition preference of the antibody, however, further studies are required to find the optimal system composition that will fractionate 100% of the antibody to the contaminants opposite phase, making this system an ideal candidate to be tested for the selectivity of CD133+ stem cells.