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result(s) for
"Romero, María Paulina"
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Carbon-Based Materials in Photodynamic and Photothermal Therapies Applied to Tumor Destruction
by
Buzzá, Hilde H.
,
Lagos, Karina J.
,
Romero, María Paulina
in
Animals
,
Antimicrobial agents
,
Cancer therapies
2021
Within phototherapy, a grand challenge in clinical cancer treatments is to develop a simple, cost-effective, and biocompatible approach to treat this disease using ultra-low doses of light. Carbon-based materials (CBM), such as graphene oxide (GO), reduced GO (r-GO), graphene quantum dots (GQDs), and carbon dots (C-DOTs), are rapidly emerging as a new class of therapeutic materials against cancer. This review summarizes the progress made in recent years regarding the applications of CBM in photodynamic (PDT) and photothermal (PTT) therapies for tumor destruction. The current understanding of the performance of modified CBM, hybrids and composites, is also addressed. This approach seeks to achieve an enhanced antitumor action by improving and modulating the properties of CBM to treat various types of cancer. Metal oxides, organic molecules, biopolymers, therapeutic drugs, among others, have been combined with CBM to treat cancer by PDT, PTT, or synergistic therapies.
Journal Article
Broad-Spectrum Antimicrobial ZnMintPc Encapsulated in Magnetic-Nanocomposites with Graphene Oxide/MWCNTs Based on Bimodal Action of Photodynamic and Photothermal Effects
by
Cuadrado, Coralia Fabiola
,
Quiroz, Francisco
,
Salazar, Mateo Alejandro
in
Antimicrobial agents
,
antimicrobial nanomaterials
,
Bacteria
2022
Microbial diseases have been declared one of the main threats to humanity, which is why, in recent years, great interest has been generated in the development of nanocomposites with antimicrobial capacity. The present work studied two magnetic nanocomposites based on graphene oxide (GO) and multiwall carbon nanotubes (MWCNTs). The synthesis of these magnetic nanocomposites consisted of three phases: first, the synthesis of iron magnetic nanoparticles (MNPs), second, the adsorption of the photosensitizer menthol-Zinc phthalocyanine (ZnMintPc) into MWCNTs and GO, and the third phase, encapsulation in poly (N-vinylcaprolactam-co-poly(ethylene glycol diacrylate)) poly (VCL-co-PEGDA) polymer VCL/PEGDA a biocompatible hydrogel, to obtain the magnetic nanocomposites VCL/PEGDA-MNPs-MWCNTs-ZnMintPc and VCL/PEGDA-MNPs-GO-ZnMintPc. In vitro studies were carried out using Escherichia coli and Staphylococcus aureus bacteria and the Candida albicans yeast based on the Photodynamic/Photothermal (PTT/PDT) effect. This research describes the nanocomposites’ optical, morphological, magnetic, and photophysical characteristics and their application as antimicrobial agents. The antimicrobial effect of magnetics nanocomposites was evaluated based on the PDT/PTT effect. For this purpose, doses of 65 mW·cm−2 with 630 nm light were used. The VCL/PEGDA-MNPs-GO-ZnMintPc nanocomposite eliminated E. coli and S. aureus colonies, while the VCL/PEGDA-MNPs-MWCNTs-ZnMintPc nanocomposite was able to kill the three types of microorganisms. Consequently, the latter is considered a broad-spectrum antimicrobial agent in PDT and PTT.
Journal Article
Bioinspired Synthesis of Magnetic Nanoparticles Based on Iron Oxides Using Orange Waste and Their Application as Photo-Activated Antibacterial Agents
by
Niebieskikwiat, Dario
,
Romero, María Paulina
,
Salazar, Mateo Alejandro
in
Animals
,
Anti-Bacterial Agents - pharmacology
,
Antibacterial agents
2023
Magnetic nanoparticles based on iron oxides (MNPs-Fe) have been proposed as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT), aiming to counteract the vast health problem of multidrug-resistant bacterial infections. We present a quick and easy green synthesis (GS) to prepare MNPs-Fe harnessing waste. Orange peel extract (organic compounds) was used as a reducing, capping, and stabilizing agent in the GS, which employed microwave (MW) irradiation to reduce the synthesis time. The produced weight, physical–chemical features and magnetic features of the MNPs-Fe were studied. Moreover, their cytotoxicity was assessed in animal cell line ATCC RAW 264.7, as well as their antibacterial activity against Staphylococcus aureus and Escherichia coli. We found that the 50GS-MNPs-Fe sample (prepared by GS, with 50% v/v of NH4OH and 50% v/v of orange peel extract) had an excellent mass yield. Its particle size was ~50 nm with the presence of an organic coating (terpenes or aldehydes). We believe that this coating improved the cell viability in extended periods (8 days) of cell culture with concentrations lower than 250 µg·mL−1, with respect to the MNPs-Fe obtained by CO and single MW, but it did not influence the antibacterial effect. The bacteria inhibition was attributed to the plasmonic of 50GS-MNPs-Fe (photothermal effect) by irradiation with red light (630 nm, 65.5 mW·cm−2, 30 min). We highlight the superparamagnetism of the 50GS-MNPs-Fe over 60 K in a broader temperature range than the MNPs-Fe obtained by CO (160.09 K) and MW (211.1 K). Therefore, 50GS-MNPs-Fe could be excellent candidates as broad-spectrum PTAs in antibacterial PTT. Furthermore, they might be employed in magnetic hyperthermia, magnetic resonance imaging, oncological treatments, and so on.
Journal Article
Synthesis and Degradation of the Phytohormone Indole-3-Acetic Acid by the Versatile Bacterium Paraburkholderia xenovorans LB400 and Its Growth Promotion of Nicotiana tabacum Plant
by
Vega-Celedón, Paulina
,
Cárdenas, Franco
,
Seeger, Michael
in
Acetic acid
,
Amino acids
,
Analysis
2024
Plant growth-promoting bacteria (PGPB) play a role in stimulating plant growth through mechanisms such as the synthesis of the phytohormone indole-3-acetic acid (IAA). The aims of this study were the characterization of IAA synthesis and degradation by the model aromatic-degrading bacterium Paraburkholderia xenovorans LB400, and its growth promotion of the Nicotiana tabacum plant. Strain LB400 was able to synthesize IAA (measured by HPLC) during growth in the presence of tryptophan and at least one additional carbon source; synthesis of anthranilic acid was also observed. RT-PCR analysis indicates that under these conditions, strain LB400 expressed the ipdC gene, which encodes indole-3-pyruvate decarboxylase, suggesting that IAA biosynthesis proceeds through the indole-3-pyruvate pathway. In addition, strain LB400 degraded IAA and grew on IAA as a sole carbon and energy source. Strain LB400 expressed the iacC and catA genes, which encode the α subunit of the aromatic-ring-hydroxylating dioxygenase in the IAA catabolic pathway and the catechol 1,2-dioxygenase, respectively, which may suggest a peripheral IAA pathway leading to the central catechol pathway. Notably, P. xenovorans LB400 promoted the growth of tobacco seedlings, increasing the number and the length of the roots. In conclusion, this study indicates that the versatile bacterium P. xenovorans LB400 is a PGPB.
Journal Article
Recognition of the microbial metabolite p-cresol in autism spectrum disorder: systematic review and meta-analysis
by
Contreras-Romero, Paulina
,
del Campo, Rosa
,
Hengst, Martha
in
autism spectrum disorder
,
gut-brain axis
,
metabolites
2025
In recent years, research has focused on the gut-brain axis and its microbial metabolites as potential etiological or physiopathological agents of autism spectrum disorders (ASDs). Elevated levels of the organic compound
-cresol (
-cresol) have been reported in various populations of children with ASD, suggesting that it could be validated as a possible ASD biomarker related to microbiota. The aim of this study was to perform a systematic review of
-cresol in ASD along with a meta-analysis to elucidate the scientific evidence of its potential as a biomarker.
A search was performed in the PubMed, Web of Science and Scopus databases in May 2024. The Axis critical appraisal tool was used to evaluate the methodological quality of the studies included in the review. Three independent reviewers examined the identified records and performed data extraction.
The systematic review yielded 15 articles, of which only 6 were ultimately used for the meta-analysis. Urinary
-cresol levels were significantly higher in those with ASD than in healthy controls, whereas no significant differences were observed in feces.
This meta-analysis validates that in ASD an increased level of
-cresol is detected in urine, which could represent a marker of microbiota evolution assessment in the pathogenesis of the disease. However, further research is needed to determine whether there is a causal relationship between the role of this metabolite and the pathophysiology of ASD and to validate its clinical utility.
Journal Article
First records of the genus Pyrolirion Herb. (Liliopsida, Asparagales, Amaryllidaceae) in Ecuador
by
Bustamante, Martin
,
Zambrano C., Ricardo
,
Meerow, Alan W.
in
Amaryllidaceae
,
Andes region
,
Bolivia
2025
We report for the first time in Ecuador the small plant genus
Pyrolirion
Herb. (Amaryllidaceae). We identify several Ecuadorian populations of
Pyrolirion tubiflorum
(L'Hér.) M. Roem. located in four provinces along the Ecuadorian Andes. This species has been previously recorded in Peru, Bolivia, and Chile. An updated description of
P. tubiflorum
is provided, along with detailed photographs of some of the Ecuadorian examples of the species.
Journal Article
Human iPSCs-based modeling unveils SETBP1 as a driver of chromatin rewiring in GATA2 deficiency
2025
Patients with GATA2 deficiency are predisposed to developing myelodysplastic neoplasms (MDS), which can progress to acute myeloid leukemia. This progression is often associated with cytogenetic and somatic alterations. Mutations in SETBP1 and ASXL1 genes are recurrently observed in GATA2 patients, although their roles remain poorly understood. Here we develop a hiPSC-based system to investigate the impact of SETBP1 and ASXL1 mutations in GATA2 deficiency. Using precise genome editing, we recreate stepwise mutational trajectories observed in GATA2-related MDS. We demonstrate that GATA2 mutation has limited impact on hematopoietic progenitors, while the co-occurrence of SETBP1 or ASXL1 mutations impairs myeloid differentiation. The combination of all three mutations severely depletes myeloid progenitors, recapitulating GATA2-related MDS and highlighting their synergistic interplay. Notably, SETBP1 mutation plays a dominant role in establishing a stable chromatin accessibility landscape, even when co-occurring with ASXL1. Our study establishes an iPSC-based model of GATA2 deficiency, offering new insights into myeloid disease progression and a platform for testing future therapeutic strategies.
GATA2 deficiency is one of the major causes of hereditary pediatric myelodysplastic neoplasms (MDS). Using iPSC-based models, this work recapitulates stepwise mutational trajectories in GATA2-related MDS and reveals their impact on myeloid differentiation.
Journal Article
In Vitro and In Vivo Antitumor Activity of a Chloroform Partition from Ibervillea sonorae (S. Watson) Greene Endophytic Bacillus subtilis Extracts
by
Arzate-Quintana, Carlos
,
Rodriguez-Garza, Nancy
,
Tamez-Guerra, Patricia
in
Anticancer properties
,
Antitumor activity
,
Antitumor agents
2025
Cancer is a complex disease due to its high variability and resistance to conventional treatments. The search for new therapies has prompted the study of less invasive natural sources, such as endophytic bacteria from medicinal plants. Bacillus subtilis is known to produce bioactive metabolites with promising pharmacological properties. This study evaluated the antitumor activity of the endophyte B. subtilis from Ibervillea sonorae against murine L5178Y-R lymphoma cells within in vitro and in vivo models. B. subtilis methanol extract was fractionated in hexane, chloroform, and methanol, with the chloroform partition showing the highest tumor cell growth inhibition (IC50 = 34.62 ± 0.180 µg/mL) and the highest selectivity index (SI = 15.53) when compared with the hexane and methanol partitions. The in vivo study showed that mice treated with 10 mg/kg of the chloroform partition significantly (p < 0.01) reduced the tumor volume and weight without affecting tumor-free body weight. The maximum tolerated dose test indicated that 10 mg/kg was safe and well tolerated. These results indicate that B. subtilis may be a promising source of selective antitumor compounds.
Journal Article
The Gill Microbiota of Argopecten purpuratus Scallop Is Dominated by Symbiotic Campylobacterota and Upwelling Intensification Differentially Affects Their Abundance
by
Lohrmann, Karin B.
,
Brokordt, Katherina
,
Henríquez-Castillo, Carlos
in
Aquaculture
,
Aquaculture products
,
Argopecten purpuratus
2022
Despite the great importance of gills for bivalve mollusks (respiration, feeding, immunity), the microbiota associated with this tissue has barely been characterized in scallops. The scallop Argopecten purpuratus is an important economic resource that is cultivated in areas where coastal upwelling is intensifying by climate change, potentially affecting host-microbiota interactions. Thus, we first characterized the bacterial community present in gills from cultivated scallops (by 16S rRNA gene amplicon sequencing) and assessed their stability and functional potential in animals under farm and laboratory conditions. Results showed that under both conditions the gill bacterial community is dominated by the phylum Campylobacterota (57%), which displays a chemoautotrophic potential that could contribute to scallop nutrition. Within this phylum, two phylotypes, namely symbionts A and B, were the most abundant; being, respectively, taxonomically affiliated to symbionts with nutritional functions in mussel gills, and to uncultured bacteria present in coral mucus. Additionally, in situ hybridization and scanning electron microscopy analyses allowed us to detect these symbionts in the gills of A. purpuratus. Given that shifts in upwelling phenology can cause disturbances to ecosystems, affecting bacteria that provide beneficial functions to the host, we further assessed the changes in the abundance of the two symbionts (via qPCR) in response to a simulated upwelling intensification. The exposure to combined decreasing values in the temperature, pH, and oxygen levels (upwelling conditions) favored the dominance of symbiont B over symbiont A; suggesting that symbiont abundances are modulated by these environmental changes. Overall, results showed that changes in the main Campylobacterota phylotypes in response to upwelling intensification could affect its symbiotic function in A. purpuratus under future climate change scenarios. These results provide the first insight into understanding how scallop gill-microbial systems adapt and respond to climate change stressors, which could be critical for managing health, nutrition, and scallop aquaculture productivity.
Journal Article
El aporte de los centros de emprendimiento y las incubadoras de empresas al ecosistema emprendedor ecuatoriano
Introduction: Entrepreneurship centers and business incubators play a crucial role in fostering competitiveness, the emergence of new activities, and self-employment, thereby promoting social cohesion within countries. This research aims to identify the main business incubators and entrepreneurship centers in Ecuador and to assess their key contributions to the entrepreneurial ecosystem. Methodology: This study adopts a qualitative research approach, employing an exploratory-descriptive methodology. Through the collection of data from secondary sources, the study identifies Ecuadorian business incubators, their affiliations with public and private organizations, their primary activities, impacts, and capacities. Results: Nationwide, 28 entrepreneurship centers, both public and private, were identified. The majority are dedicated to guiding entrepreneurs in developing their business models, whether in the initial stages or during expansion, through advisory services, training in various fields, and even financing. Conclusions: While there is evident close collaboration between academia and the private sector, current efforts prioritize promoting the entrepreneurial spirit over the practical implementation of ideas, project capitalization, or addressing specific industrial or social challenges. Therefore, it is necessary to balance these efforts to ensure that entrepreneurial initiatives are not only encouraged but also realized and generate a tangible impact.
Journal Article