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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- Centrifugal microfluidic platform for applications in low-concentration biosensing of E. Coli(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-11) Farías Álvarez, Mario Alfredo; Madadelahi, Masoud; emimmayorquin, emipsanchez; Salinas Salazar, Carmen Lizzeth; Pilloni Choreño, Oscar; School of Engineering and Sciences; Campus MonterreyAccess to clean and drinkable water is not yet a possibility in many parts of the world. In different regions or rural areas where common water sources are prone to contamination or places where the water treatment does not follow a strict and efficient protocol for disinfection and purification, different pathogens can end up being consumed by several people. Water in these and other places can be contaminated with relative ease, potentially facing from hundreds to thousands of deaths all around the world from diseases caused by unsafe water treatment and pathogenic bacteria. The bacteria Escherichia Coli O157:H7 is a highly pathogenic bacteria that causes a series of gastrointestinal complications and diseases. If left untreated, the consequences can be fatal. Because of this, the need for early detection of this pathogen in water supplies is of great importance. Aptamers are single-stranded chains of DNA or RNA whose sequence can be designed to fold into specific shapes. They can act as an alternative to antibodies for the recognition and binding to antigens and targets of interest. Aptamers have been studied for this potential, and have been successfully synthesized to bind to components in the outer cell membrane of pathogenic bacteria, allowing for a high selectivity. Dendrimers are poly-branched polymers that have the advantage of being able to grow to various generations, exponentially increasing the number of branches they have. Polyamidoamine dendrimers have been studied and researched for their potential in biomedical applications. The functional groups of the branches can be modified and have attached a functional group with the purpose of integrating them into sensing devices. The multiple branches of polyamidoamine dendrimers can then serve as multiple attachment sites for aptamer placement, increasing the amount of bacteria-capturing agents on a biosensing surface. Flow reciprocation is a concept that has been introduced in microfluidic devices, and consists in driving the fluid either actively or passively through a a microfluidic circuit in two directions. This can allow the fluid sample to return to the source or point of origin in the microfluidic device. This concept can be present in centrifugal microfluidics, in which passive ways of reciprocation have been implemented successfully. Pneumatic chambers have been used in order to achieve flow reciprocation by compressing air during the rotation of the device and expanding it during its deceleration. The compression of air is caused by the fluid entering the pneumatic chamber, and it returns to the source chamber due to the air expansion. Since this technique requires high rotational velocities, an alternative is to use flexible membranes as passive pumps that inflate upon rotation and relax during deceleration. These membranes allow for lower rotational speeds and the potential of ease of reciprocation. Flow reciprocation can then be used in biosensors to increase the interaction between the target and the biosensing surface. Then, this can be applied to increase the capturing of pathogenic bacteria by combining this concept with aptamers and dendrimers to achieve low limits of detection. Trial and error of microfluidic devices designs often leads to unused devices that end up discarded and in the trash, which translates into material going to waste. In order to optimize the design and save fabrication resources, computational simulations can be of use. By modeling the desired microfluidic device, one can change any relevant parameters before the actual fabrication of the final device. Lumped-element models are representations of a microfluidic circuit in which each component is governed by its own set of equations and global, system-wide variables are transmitted through ports, obeying Kirchhoff’s laws. The present work aims to combine all of these concepts into a centrifugal microfluidic device for the detection of Escherichia Coli O157:H7 pathogenic bacteria, utilizing aptamers attached to polyamidoamine dendrimers to have multiple capturing sites and using flow reciprocation to enhance the interaction between the bacteria and the aptamers for increased capturing. Fur- thermore, it aims to further develop a lumped-element model for the simulation of centrifugal microfluidic devices, incorporating a new component with elastic membranes for the purpose of flow reciprocation. A limit of detection of 8.137 × 103 CFU/mL was achieved.
- Microbial tale: using chaotic bioprinting to create a structured multi-strain probiotic(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-18) Flores Loera, Francisco Javier; Alvarez, Mario Moises; emipsanchez; Luna Aguirre, Claudia Maribel; Rocha Pizaña, María del Refugio; School of Engineering and Sciences; Campus Monterrey; Trujillo de Santiago, GrisselProbiotic therapies offer great potential for addressing gut dysbiosis, but current approaches are limited by low strain diversity, high production costs, and the challenges of culturing strict anaerobes. To overcome these limitations, this work introduces a novel strategy combining based on continuous chaotic bioprinting to create structured (micro-architected) co-cultures of probiotic bacteria. Using a Kenics static mixer–based printhead, we fabricated alginate hydrogel filaments with an internal multilayered microarchitecture containing four probiotic strains: Bifidobacterium bifidum, Bacteroides fragilis, Lactobacillus rhamnosus, and Streptococcus thermophilus. The spatial arrangement of the multilayered architecture was designed to promote cooperative interactions, particularly by embedding strict anaerobes between facultative anaerobes to create self-sustaining hypoxic niches. The printed constructs were characterized over 72 hours using fluorescence microscopy, colony-forming unit counts, LIVE/DEAD assays, and qPCR. Results showed that structured co-cultures exhibited higher viability, enhanced growth, and more balanced population dynamics than the monocultures of each bacterial strain and unstructured (scrambled) co-cultures. This study demonstrates that chaotic bioprinting enables precise spatial control over microbial ecosystems, allowing the rational design of microbial communities with tailored interactions. The approach presents a powerful and scalable platform for next-generation probiotic production and opens new opportunities for engineered microbiomes, synthetic biology, and living material design.
- Use of nanoparticles of copper with plant extracts as an alternative against multidrug-resistant bacteria causing urinary tract infections(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-08-29) De la Rosa Santana, Uriel; TORRES HUERTA, ANA LAURA; 207433; Torres Huerta, Ana Laura; emipsanchez; Hernández Cooper, Ernesto Manuel; Ordaz Cortés, Alberto; Tapia Ramírez, José Isabel; Escuela de Ingeniería y Ciencias; Campus Estado de México; António Pérez, AuroraThere is increasing concern due to the high incidence of multi-resistant bacteria. The importance of these microorganisms is in the economic and health impact that cause at global level in different countries. Many efforts have been made to improve drugs to attack these bacteria, however in the long term this only aggravates the situation. Due to this, alternatives that allow to reverse this situation are necessary. Thanks to the development of nanotechnology, the importance of nanoparticles has increased in the last years to fight infections. The green synthesis process is particularly appealing. It has been reported the use of plant extracts as reducing agents allows obtaining metallic nanoparticles with antibacterial activity. That is why in this project copper nanoparticles (CuNPs) with green synthesis were obtained. For this, extracts of Azadiractha Indica (Neem) and Eysenhardtia Polystachia (Palo Azul) were used given a previously reported medicinal properties in urinary tract infections and their high content of metabolites as reducing agents for the formation of nanoparticles (NPs). The extracts were characterized at different conditions of time and temperature, by IFTR (Fourier transform infrared) and UV-vis. Following this, mixtures of the selected extract with solutions of copper precursor salt at a specific concentration were heated under constant stirring for 20 h, taking samples at 4-hour intervals. The obtained nanoparticles were analyzed in terms of distribution, size, morphology, and concentration through dynamic light scattering (DLS) and scanning electron microscopy (SEM). Meanwhile, the characterization of its antimicrobial effect was determined thanks to absorbance analysis in liquid culture and plate reader. It was observed that as the synthesis time passes, the size of the nanoparticle tends to reduce. On the other hand, its morphology shows signs of being colloidal, although not uniformly. Meanwhile, when comparing the nanoparticles made with both extracts and different precursor salts, a different size trend was observed in nanoparticles. in terms of antibacterial activity, it was observed that the synthesis time at 20 h of the process shows an insight of bacteriostatic activity compared to a shorter stirring time. Meanwhile an indication of concentration-dependent inhibition was observed. On the other hand, it was observed that the combination of Neem extract with copper nitrate precursor salt is the best option for inhibition of bacteria. However, it is necessary to carry out more studies of antibacterial effects to guarantee its effectiveness to be an alternative to conventional antibiotic treatments.
- Characterization of the chromium reduction activity of an endemic bacterium from the Atoyac river with potential use in water bioremediation(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-06-15) Puón Meraz, Ramón Iván; CARDENAS CHAVEZ, DIANA LINDA; 46659; Cárdenas Chávez, Diana Linda; puelquio; Luna, Itza Eloisa; Gutiérrez Uribe, Janet Alejandra; Rocha Pizaña, Maria del Refugio; Escuela de Ingeniería y Ciencias; Campus MonterreyWater pollution has become a major issue all over the world. One of the most devastating examples in Mexico is the Atoyac River, a victim mainly of the textile and automotive industries that produce contaminants such as phenolic compounds or heavy metals. Most of the contaminants in water bodies turn these ecosystems practically lifeless. However, unicellular organisms seem to be the only beings that thrive in polluted rivers. Bacteria are receiving more attention as model systems for bioremediation applications, given their availability and wide diversification in extreme ecosystems. This, in combination with the relative simplicity of the techniques for receiving genetic modifications, makes them ideal candidates as a source of biomolecules that might be used in the development of biosensors for monitoring the presence of pollutants in situ. Here, I propose a thesis whose main objective is to identify the possible mechanism, mainly the mediated by enzymes, of the hexavalent chromium reduction by an endemic bacterium (named Cr2.23a) isolated from the Atoyac River. In the characterization of this bacterial strain, it showed an optimal chromium reduction growing at pH of 8 and a temperature of 42°C. This reduction was localized on intracellular extracts, that would increase its efficiency by adding external electron donors such as glucose, lactose, sodium acetate, and NADPH. An API biochemical test identified this Cr 2.23a strain as two possible species: Klebsiella oxytoca and Raoultella planticola. To confirm these identification results, the 16s region of this strain was cloned and isolated. The molecular isolates were sent for sequencing to the Instituto Potosino de Investigación Científica y Tecnológica. These results will allow for the development of new strategies for water bioremediation and possibly a microbial biosensor for the detection of polluted bodies of water by heavy metals.
