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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- Characterization of the effect of UV-A light and agitation on the exopolysaccharide production of Chlorella vulgaris and Porphyridium cruentum(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-05) Garza Rodríguez, Zaida Berenice; GARZA RODRIGUEZ, ZAIDA BERENICE; 838147; Benavides Lozano, Jorge Alejandro; emipsanchez; Jacobo Velázquez, Daniel Alberto; Santacruz López, Yolanda Arlette; School of Engineering and Sciences; Campus Monterrey; Hernández Pérez, JesúsMicroalgae species are photosynthetic microorganisms that are a sustainable source of bioproducts due to their ability to reduce anthropogenic carbon dioxide in the atmosphere. The number of studies focused on their biologically active molecules, such as lipids, proteins, polysaccharides, and pigments, has been increasing in the last years due to their promising application as valuable products. In this context, the exopolysaccharides (EPS) from microalgal sources stand out as high-value molecules for their potential applications in the nutraceutical and pharmaceutical industries. However, studies aimed to find strategies and optimal conditions to promote the biosynthesis of EPS are still required to make these molecules economically feasible. The effect of ultraviolet light A (UV-A) is studied on biomass and EPS productivity of the red microalgae Porphyridium cruentum and the green microalgae Chlorella vulgaris testing three levels: L0, L1 and L2. Likewise, the effect of the agitation factor on cell growth and EPS productivity are analyzed for the two microalgae species testing two levels: A0 and A1. After recovering the EPS using centrifugation and diafiltration, their potential antioxidant activity was tested using the 2,2-Diphenyl-1-prykylhydrazyl (DPPH) radical scavenging assay. The UV-A light (315-400 nm), along with photosynthetic active radiation (PAR) increased EPS productivity in both C. vulgaris and P. cruentum to 1.21-fold and 2.43-fold, respectively, compared to light control conditions (PAR at 35.6 µmol m⁻² s⁻ ¹). The highest P. cruentum EPS productivity was 8.67 mg/g DW biomass at the highest tested UV-A level and lowest agitation(L2A0), and the highest biomass concentration was 8.57 g/L at the highest agitation (A1) due to a possible improvement in nutrient distribution. For C. vulgaris, the highest productivity was 1380 mg/g DW biomass at intermediate UV-A light level (L1). The highest biomass concentration of C. vulgaris was 0.34 g/L at the highest UV-A level (L2), treatment that conversely displayed the lowest EPS productivity (73.08 mg/g DW biomass). The study of antioxidant activity revealed that EPS show DPPH radical scavenging activity. The mean highest radical scavenging effect (%) of P. cruentum and C. vulgaris EPS was 56.48 ± 4.46 and 46.31 ± 3.2 at 4 mg/mL and 2 mg/mL, respectively. This work contributes to the characterization of abiotic factors that could potentially influence the production of high-value EPS molecules that display bioactivity of interest for health applications.
- Synergistic interaction between lac and uspA promoters’ expression systems for recombinant protein production in Escherichia coli(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-06) Méndez Chavero, Jessica Paola; Benavides Lozano, Jorge Alejandro; puemcuervo/tolmquevedo; Chávez Santoscoy, Rocío Alejandra; Vargas Cortez, Teresa; School of Engineering and Sciences; Campus Monterrey; Hernández Pérez, JesúsRecombinant proteins need to be produced on a large-scale, short time and at a low cost. Different elements need to be controlled to achieve these characteristics. One of the most relevant is the promoter sequence since it is responsible for initiating the transcription process. Several promoters are already commercially used, but none is suitable for high-scale protein production due to the cost of the induction method, the leaky expression, the limited media options, etc. Furthermore, most current expression systems rely on the single use of a promoter to control the gene transcription. At the same time, in nature, this is not always the case since there are tandem promoters’ arraignments in control of a single gene. Using tandem promoters is an attractive idea to enhance the recombinant protein production considering that this significate the incorporation of more sites where the RNAP-complex could bind, enhancing recombinant protein production this way. Based on this, a triple-promoter expression system was developed in Escherichia coli to improve the yields of the red fluorescent recombinant protein (mRFP1). Two copies of the well-known and established lac promoter were used, and the sequence of the uspA promoter, which is the promoter of the most abundant protein in Escherichia coli according to the Protein Abundance Database PAXdb4.1, were used in this system. Additionally, the uspA promoter can be induced by several stress conditions. Thus, it was tested under oxidative starvation. Results indicated a 0.82 FU µg-1 mL-1 and 0.8 FU µg-1 mL yields of the mRFP1 when using the triple-promoter expression systems compared to a 0.59 FU µg-1 mL-1 of the single-promoter expression system. Thus, indicating an enhancement in the production yields of the target protein. These results are promising and open an opportunity for further research in the multiple-promoter system.
- Design and characterization of an adhesive and pH-indicating hydrogel with gentamicin release as a proof of concept for its potential use as an acute wound dressing(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-06) Viaña Mendieta, Pamela; Benavides Lozano, Jorge Alejandro; puemcuervo; Antunes Ricardo, Marilena; Mata Gómez, Marco Arnulfo; School of Engineering and Sciences; Campus Monterrey; Sánchez, Mirna LorenaWound care cost is an overwhelming problem aggravated by the burning of skin injuries and the overuse of traditional materials that are low cost-efficient. Modern wound care strives for multifunctional wound dressings to monitor physiological conditions and prevent wound infection or non-healing processes. Thus, this study addresses the synthesis and characterization of an adhesive and pH-indicating hydrogel dressing with gentamicin release for the potential acceleration and monitoring of acute wounds. The proposed hydrogels were prepared by physical and chemical crosslinking of polyvinyl alcohol (PVA), phenol red, glycerol, citric acid (CA), butyl-cyanoacrylate (BCA), and gentamicin. Diverse formulations, varying PVA and CA concentration, were evaluated and selected by the stable swelling profile. Then, the selected formulation was characterized by swelling degree, colorimetric pH-change evaluations, adhesion and dehydration assay, and drug release profile. The selected formulation was 4% wt. PVA, 5% wt. CA, 10% wt. glycerol and 1.5% wt. BCA, and showed excellent properties as a wound dressing. It had uniform transparency, a good pH-indicating property, enough water content, stable swelling degree and gentamicin release. Thus, the pH-indicating property showed the transition of pH 4 to 9, with sensitive pH change by forming the circle-like pattern at pH 8 and 9. The dehydration ratio was 1.0 and maintained adhesion to a plastic surface for 96 h. The release of gentamicin was enough in 24 h (96.3 %). Based on the results, this proof of concept concludes that the designed multifunctional hydrogel has suitable properties as a potential wound dressing. This study shows the opportunity to continue its characterization in detail in searching for a potential commercial wound dressing.
- Effects of acetaminophen, diclofenac and ibuprofen exposure on growth, viability, photosynthetic pigment production and gene expression in Synechococcus elongatus for the assessment of its bioremediation potential(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-18) Castillo Escalante, Francisco Adrián; Benavides Lozano, Jorge Alejandro; tolmquevedo; González Valdéz, José Guillermo; Santacruz López, Yolanda Arlette; Escuela de Ingeniería y Ciencias; Campus Monterrey; Hernandez Pérez, JesúsThe extensive use of pharmaceuticals has led to the accumulation of emergent pollutants with potential toxicity to aquatic organisms in water bodies around the world. Non-steroidal anti-inflammatory drugs (NSAIDs), such as acetaminophen (ACP), diclofenac (DCF) and ibuprofen (IBU) are amongst the most prevalent pharmaceuticals found in surface water and wastewater at levels up to 10,000 ng/L. In the present work, a Mexican strain of Synechococcus elongatus was selected to characterize the effects of ACP, DCF and IBU on the cyanobacteria growth rate, viability, photosynthetic pigment content (chlorophyll, carotenoids and phycobiliproteins), and expression level of three stress-related genes (aphC, htpG, and mutM). S. elongatus was able to tolerate continued exposure to ACP and DCF with 2.43% and 12.40% inhibition to its growth rate under ACP and DCF, respectively; exposure to IBU led to complete growth inhibition. Cultures treated with ACP and DCF did not show significant change in chlorophyll and phycobiliprotein content but did show a statistically significant increase in carotenoids (13.90% under ACP, p < 0.05) after 10 days of culture. IBU treated cultures presented total loss of photosynthetic pigments except for chlorophyll, with a 70% decrease compared to control, showing a similar state to chlorosis in cyanobacteria. RNA levels showed an increase in aphC expression under all treatments but was only statistically significant under DCF (6.29-fold increase, p < 0.05); expression of htpG and mutM was downregulated without statistical significance under all treatments. These results suggest an increase in the antioxidant defense response (aphC) against reactive oxygen species under exposure to NSAIDs. Finally, S. elongatus was not able to decrease the level of NSAIDs present in the culture. This research work presents a deeper understanding of the effect of contaminant NSAIDs over cyanobacteria and suggests a potential industrial application of S: elongatus culture under pharmaceutical-contaminated wastewater.
- Cuantificación y caracterización del comportamiento de partición de la Ribonucleasa A y sus conjugados polímero - proteína en sistemas de dos fases acuosas polímero - sal-Edición Única(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2009-05-01) González Valdéz, José G.; Benavides Lozano, Jorge Alejandro; Rito Palomares, Marco Antonio; Partida Martínez, Laila Pamela; Tecnológico de Monterrey, Campus MonterreyRibonuclease A from bovine pancreas and its PEGylated conjugates has proven to have several potential therapeutic applications. Aqueous Two-Phase Systems (ATPS) is a promising primary recovery strategy for the fractionation of proteins and their PEGylated conjugates. However, in order to characterize the partition behavior of these molecules in ATPS, an easy to implement method is needed to estimate protein concentration in each phase. Because RNase A quantification based on colorimetric methods usually renders poor sensitivity, this paper presents a methodology based on UV absorbance to quantify RNase A and its PEGylated conjugates on polymer (polyethylene glycol; PEG) and salt (potassium phosphate; PO4) rich environments, simulating conditions found on polymer – salt ATPS. The effect of PEG and PO4 concentrations and the effect of grafted PEG chains on RNase A upon UV absorbance were evaluated. Polymer and salt concentrations have a significant effect on RNase A absorbance, reflecting the need of specific standard curves in order to consider the impact of the chemical forming phase upon the extinction coefficient. The absorbance ratios at 280 nm between mono-PEGylated RNase A/native RNase A and diPEGylated RNase A/native RNase A in PEG and potassium phosphate free environments were found to be 0.32 and 0.46, respectively, demonstrating that the grafted PEG chains have also an important effect upon protein light absorbance. The method presented results in an easy-to-implement alternative, to chromatographic approaches, since just an UV-visible spectrophotometer or plate reader is required.
- characterization of serine-proteases from P. hypophthalmus epithelial mucus as a potential feedstock for biocosmetic applications(Instituto Tecnológico y de Estudios Superiores de Monterrey) 0000-0001-9343-3582; Avila Rodríguez, María Isabela; Benavides Lozano, Jorge Alejandro; Jacobo, Daniel; Romero Robles, Laura; Ingeniería y Ciencias; Ingeniería y Ciencias; Campus Monterrey; Sánchez, Mirna LorenaChemical peeling is a cosmetical treatment that promotes skin renewal, by the remotion of skin layers through the appliance of corrosive compounds. It has proven to be successful for the removal of acne, scars, photoaging, and pigmentary lesions. Yet this procedure is aggressive and can produce several complications, among them infections, eruptions, erythema or scarring. As an alternative, enzymatic peelings have been proposed. Enzymes lead natural desquamation processes, principally by serine proteases (SP). SP have also been identified in fish epithelial mucus. As well, empirical evidence has shown that direct contact with Iridescent shark (Pangasius hypophthalmus) epithelial mucus, promotes skin regeneration. Hence, through the present study, the characterization of the proteases present in P. hypophthalmus epithelial mucus was held, in order to identify new SP with potential cosmetical use. Epithelial mucus was extracted by rinsing specimens in extraction buffer (NaCl 50mM pH 7.4) in polyethylene bags and held back to tank. The obtained extracts were pooled and centrifuged. Supernatant was concentrated and desalted using vacuum evaporation and PD-10 columns. Protease activity was evaluated through caseinolytic activity and zymography using casein and gelatin universal protease substrates. Also in-gel inhibition (PMSF, benzamidine, EDTA, O-phenanthroline, and iodoacetamide) and activation (Zn2+ , Ca2+ , K+ , Na+ and no ion) for specific protease families were evaluated. Caseinolytic activity was detected (5.33 ± 0.37 U/mg at 25 oC). As for zymography, active bands within 130-15 kDa were identified for gelatin, while only one active band of 63 kDa was identified for casein. Compared to control treatment (Zn2+), K+ and Na+ enhanced gelatinolytic activity of medium weight bands (63, 58 and 48 kDa), while Ca2+ depleted most protease activity. Serine and cysteine protease inhibitors, PMSF and iodoacetamide, excerpted similar inhibition by reducing 63 kDa and inhibiting 58, 56, 30 kDa activity. MMP inhibitors exerted slight inhibition to superior weight bands (114, 90 and 71 kDa). Benzamidine only depleted 45 kDa activity. The present study proves the presence of the MMPs and SPs within P. hypophthalmus epithelial mucus. This positive result opens the possibility for further protease characterization and isolation for their evaluation as feasible agents for biocosmetic treatments.