Browsing by Autor "Juan C. Cruz"

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A new in vitro pre-clinical method for testing SARS-CoV-2 nasopharyngeal swabs
(Nature Portfolio, 2025) Ian C. Orjuela-Garzón; Inés María Fernández-Calderón; Marta Ayala; M. Soto; Camilo Eduardo Pérez-Cualtán; Camila Castro-Páez; Juan C. Cruz; Carolina Muñoz-Camargo; Javier Navarro; Rodrigo Cabrera
CFD Simulation and Validation of Flow in Small Arteries to Enable Further Drug Delivery Studies
(Universidad de Antioquia, 2019) Marcela Mercado‐Montoya; Juan C. Cruz; Alher Mauricio Hernández
Treatments based on nanocarriers such as nanoparticles have emerged as alternatives to overcome common limitations and side effects caused by traditional treatments against cancer and neurological diseases. The main attribute of nanoparticles stems from the fact that they can transport pharmacological agents in a guided manner. This allows drugs to selectively target diseased rather than healthy tissues. This work was aimed at modeling and simulating fluid flow inside small arteries and experimentally validating the model through quantitative measurements of pressure and flow rates. The validity of the model was evaluated in the light of different indexes of percentage agreement between simulated and measured values. The model was previously verified via mesh convergence analysis and qualitative observations of velocity profile. Our findings provide a robust basis for studying nanoparticle transport in arteries as the developed platform enables their releasing and remote manipulation both in silico and in vitro.
Extensión agrícola para la adopción de prácticas tecnológicas en países en desarrollo: una revisión exploratoria de los obstáculos y sus dimensiones
(2025) Julián F. Becerra-Encinale; Paloma Bernal-Hernández; Jorge A. Beltrán-Giraldo; Alexandre P. Cooman; Luis H. Reyes; Juan C. Cruz
Esta revisión exploratoria utilizó el marco PRISMA-ScR para analizar las complejidades de la extensión tecnológica en la agricultura en países en desarrollo, donde las diversas facetas socioeconómicas, culturales y ambientales influyen profundamente en sus estrategias. El objetivo de este estudio es identificar y ampliar el conocimiento existente de los factores críticos, tanto dificultades como oportunidades, que afectan la eficacia de la extensión agrícola con un enfoque en las variaciones contextuales. Para ello, se realizó una revisión exhaustiva de las contribuciones académicas relevantes a partir de 2013. Esto incluyó artículos, reseñas, actas de conferencias, capítulos de libros y documentos de datos. El análisis se centró en la dinámica de interacción entre el personal de extensión y los agricultores, la adaptación de tecnologías a los contextos locales y la importancia de la colaboración intersectorial. A través del análisis bibliométrico se presenta una síntesis de 32 registros pertinentes. Los hallazgos proponen un cambio de paradigma de la transferencia lineal tradicional del conocimiento a un enfoque más completo que valore la comunicación bidireccional, la conciencia cultural y la participación de las comunidades agrícolas locales. Se aboga por prácticas de extensión que estén en sintonía con la dinámica ambiental, promuevan la sostenibilidad económica a largo plazo y estén informadas por perspectivas teóricas que puedan refinar el diseño de sistemas y modelos de extensión. Esta revisión plantea que la mejora de la adopción de tecnología agrícola sostenible pasa por una profunda reforma de los sistemas de extensión. Tal reforma debe centrarse en modelos operativos y de diseño más inclusivos, adaptativos y en sintonía con las complejas realidades de los agricultores de las economías emergentes. Este enfoque integrador, sistémico y holístico propone un marco para impulsar la sostenibilidad agrícola y el desarrollo rural.
Formulation and characterization of gelatin-based hydrogels for the encapsulation of Kluyveromyces lactis and chitosan nanoparticles: biotech and biomedical applications
(2020) Luis H. Reyes; Jorge Luis Patarroyo; Juan C. Cruz
A difficulty when orally administering microorganism-based probiotics is the significant loss of their bioactivity as they pass through the gastrointestinal (GI) tract. To overcome these issues, we propose to encapsulate the probiotic yeast Kluyveromyces lactis on chemically crosslinked gelatin hydrogels to protect the bioactive agents in different environments. Moreover, a challenge to obtain favorable results with therapeutic drugs and biomolecules is the inefficient process of cellular administration. For this reason, we considered chitosan and gelatin nanoparticle loading systems to improve therapeutic efficacy . Also, we prepared hydrogels to encapsulate such nanoparticles by the chemical crosslinking of gelatin, an inexpensive and commercially available polymer. This is crucial to ensure scalability and cost-effectiveness. To explore changes in key physicochemical parameters and their impact on cell viability, we varied the concentration of the crosslinking agent (glutaraldehyde) and the gelatin. The synthesized hydrogels were characterized in terms of morphological, physical-chemical, mechanical, thermal, and rheological properties. This comprehensive characterization allowed us to identify critical parameters to facilitate encapsulation and enhance the system performance. Mainly due to pore size in the range of 5–10 µm, sufficient rigidity (breaking forces of about 1 N), low brittleness and structural stability under swelling and relatively high shear conditions, we selected hydrogels with a high concentration of gelatin (7.5% (w/v)) and concentrations of the crosslinking agent of 3.0% and 5.0% (w/w) for cell and nanoparticles encapsulation. Yeasts were encapsulated and subsequently tested in bioreactor operation and GI tract simulated media, thereby leading to cell viability levels that approached 95% and 50%, respectively. After testing, the hydrogels’ firmness was only reduced to half of the initial value and maintained resistance to shear even under extreme pH conditions. These encouraging results indicate that the proposed encapsulates are suitable to overcome most of the major issues of oral administration of drugs and probiotics and open the possibility to explore additional biotech applications further.
Hacia una educación en ingeniería aumentada por IA
(2025) Luis H. Reyes; Juan C. Cruz
La aparición de la Inteligencia Artificial Generativa (GenAI) ha creado un momento decisivo en la educación superior, desafiando fundamentalmente los métodos tradicionales de enseñanza y evaluación. Los educadores de todas las disciplinas enfrentan la tarea crítica de incorporar GenAI en su enseñanza mientras garantizan que los estudiantes desarrollen habilidades esenciales de pensamiento crítico y análisis. Esta contribución propone el Marco de Sinergia Cognitiva-IA (CASF), un enfoque novedoso para integrar la Inteligencia Artificial Generativa en la educación. CASF sintetiza el modelo pedagógico dialógico de De Zubiría con la Escala de Evaluación de Inteligencia Artificial (AIAS) para alinear la integración de GenAI con las etapas de desarrollo cognitivo de los estudiantes. Nuestro marco recientemente introducido aborda el desafío de incorporar efectivamente las herramientas de GenAI en la educación mientras se asegura el desarrollo de habilidades fundamentales y capacidades de pensamiento crítico. Para demostrar la implementación práctica, presentamos el Asistente de Implementación CASF, que ha evolucionado desde un simple asistente de IA hasta un agente estructurado en n8n con flujo de conversación mejorado y comprensión contextual. Esta herramienta proporciona orientación personalizada a los educadores para integrar la IA basada en los niveles cognitivos de los estudiantes y los requisitos del curso. Discutimos los desafíos potenciales en la implementación de CASF, incluida la complejidad de alinear los métodos de enseñanza con los niveles cognitivos y el riesgo de dependencia excesiva de GenAI. Para abordar estos desafíos, proporcionamos recomendaciones integrales y buenas prácticas para educadores que implementan CASF.
Implementación de un asistente de IA generativa en la enseñanza de fenómenos de transporte biológico: estrategias, resultados y perspectivas
(2025) A. Barreras; Santiago Serrano; José Bestier Padilla Bejarano; Rubby Casallas; Luis H. Reyes; Juan C. Cruz
La inteligencia artificial generativa (IAGen) está transformando la enseñanza en ingeniería al facilitar la comprensión de conceptos complejos y fomentar el aprendizaje personalizado. Este trabajo presenta BioFlow, un asistente inteligente diseñado para apoyar a los estudiantes del curso de Fenómenos de Transporte Biológico mediante preguntas de práctica, retroalimentación guiada y repasos temáticos. Desarrollado como parte de la estrategia institucional de IAGen de la Universidad de los Andes, BioFlow integra modelos de lenguaje natural en una arquitectura modular con tres casos de uso. Ha sido probado en plataformas como OpenAI y Copilot Studio, y actualmente se proyecta su migración a n8n. Encuestas aplicadas en cuatro periodos académicos revelan una alta valoración por parte de los estudiantes, quienes destacaron su utilidad, facilidad de uso y pertinencia conceptual. A pesar de algunas limitaciones técnicas, los resultados confirman su potencial como herramienta educativa flexible, replicable y alineada con principios pedagógicos y éticos.
Magnetoliposomes for nanomedicine: synthesis, characterization, and applications in drug, gene, and peptide delivery
(Taylor & Francis, 2025) Cristian F. Rodríguez; Paula Guzmán-Sastoque; Alan Santacruz-Belalcazar; C. Jorge Laureano Moya Rodríguez; Paula Villamarin; Luis H. Reyes; Juan C. Cruz
While magnetoliposomes show remarkable therapeutic versatility, their clinical translation requires addressing biocompatibility concerns, manufacturing scalability, and regulatory hurdles. Integration with artificial intelligence, organ-on-chip technologies, and personalized medicine approaches will likely accelerate their development toward clinical reality, potentially revolutionizing treatment paradigms for complex diseases through tailored therapeutic interventions.
Molecular dynamics simulations of Alzheimer's BACE1 and BACE2 transmembrane domains in neurons: Impact of cholesterol
(Universidad de Antioquia, 2020) Juan C. Cruz; Marcela Mercado‐Montoya; C. Ostos; Alher Mauricio Hernández
Molecular dynamic (MD) simulation is an approach frequently employed in computational biology for exhaustive sampling of the protein-ligand conformational space. Hence, it is useful for structural analysis and the study of molecular interactions. In this study, we report on a MD simulation protocol to understand the dynamics of β-secretase 1 (BACE1) and 2 (BACE2), widely known to play a critical role in the etiology of Alzheimer’s disease, by a structure change evaluation of their transmembrane domains while inserted in a simulated neural membrane system. We considered two different levels in membrane cholesterol content. Because there is no evidence supporting the capacity of BACE1 and BACE2 to exist as a dimer, single and double (BACE1/BACE1, BACE2/BACE2, BACE1/BACE2) systems, either in parallel or antiparallel orientation, were prepared for each run. Analysis of tridimensional structure of BACE1 and BACE2, after 10ns of MD simulation, revealed a correlation between higher cholesterol levels and both peptide refolding and changes in the secondary structure of both transmembrane domains in single and double systems. Interestingly, our results also indicate a potential interaction in the double system BACE2/BACE2, particularly when the domains had an antiparallel orientation.
Porcine small intestinal submucosa (SIS) and graphene oxide/reduced graphene oxide scaffolds for potential application in electrostimulation therapy: preliminary formulation and characterization
(2020) Juan C. Cruz; Javier Cifuentes; Julian A. Serna; Carolina Muñoz-Camargo
Chronic wounds are a health problem of enormous magnitude that affects millions of patients around the world. The most promising treatments for chronic wounds healing are the therapies related to the development of biomimetic technologies that successfully improve cell migration, growth and proliferation. The implementation of scaffolds or hydrogels, based on natural and biosynthetic extracellular matrix (ECM) or individual components of ECM, have shown to provide an adequate environment to enhance cellular migration, angiogenesis and regulation of wound healing processes. Additionally, electrostimulation therapies have gained attention in recent years due to their capability for simulating electric currents to direct cell migration, promote cell proliferation and increase oxygenated blood perfusion towards damaged tissues. In the present work, we propose innovative regenerative 3D scaffolds based on small intestinal submucosa (SIS) combined with graphene oxide (GO)/reduced graphene oxide (rGO) to improve their electrical conductivity such that they can be potentially applied in the healing of chronic wounds. To achieve this, decellularized SIS was obtained and mixed with GO flakes to make 3D scaffolds that were chemically crosslinked and reduced in-situ. GO and rGO were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, atomic force microscopy (AFM) and the four-point probe conductivity method. These techniques confirmed the effective synthesis of GO, the reduction to rGO and the improvement of electrical conductivity. Crosslinked SIS, SIS-GO and SIS-rGO scaffolds were characterized by FTIR, TGA, SEM, Raman spectroscopy and liquid displacement method. In addition, the biocompatibility of scaffolds was carried out via hemolysis activity, platelet aggregation, and cytotoxicity in Vero cells. Experiments revealed high hemocompatibility, low cytotoxicity and no significant impact on platelet aggregation. Finally, microscopic structure characteristics and cell attachment abilities demonstrated the potential of the developed technology for multiple applications in tissue engineering and regenerative medicine.
Remediación biotecnológica de malos olores generados en ambientes acuáticos contaminados mediante biofiltración con consorcios microbianos especializados
(2025) Gabriela Meléndez Plata; Jesus Acevedo Mastrogiacomo; Martha Lizeth Castellanos Ordóñez; Marta Torres; Jorge M. Gómez; Juan C. Cruz; Luis Barrios
La presencia de sulfuro de hidrógeno (H₂S) y compuestos sulfurados en cuerpos de agua contaminados representa un desafío ambiental y operativo. Para abordarlo, se desarrolló y evaluó un consorcio bacteriano especializado en oxidar H₂S, inoculado en un biofiltro tipo biopercolador (ECOFILTRO) ubicado en la Central Hidroeléctrica El Paraíso de ENEL Colombia S.A. E.S.P. El consorcio se obtuvo a partir de muestras del ECOFILTRO, el embalse de Muña, un biofiltro y una zona húmeda (Dangos), utilizando un medio mineral específico. Se aplicó una estrategia de enriquecimiento en matraces y biorreactores de 5 L, monitoreando pH y densidad óptica. Este consorcio oxidó compuestos sulfurados generando ácido sulfúrico, con cinética descrita por la ecuación de Monod (µ = 0,1 1/h). En planta, la inoculación por etapas y el control de pH facilitaron su adaptación, evidenciada por la disminución del pH y la formación de BaSO₄. La eficiencia del ECOFILTRO aumentó de 67.5 % a 78 %. Tinciones de Gram confirmaron la presencia de bacterias gram negativas, indicando una selección adecuada. Estos resultados validan el uso de consorcios microbianos enriquecidos como estrategia de biorremediación en ambientes reales para el control de olores y eliminación de compuestos sulfurados.
Unlocking cellular barriers: silica nanoparticles and fullerenol conjugated cell-penetrating agents for enhanced intracellular drug delivery
(Frontiers Media, 2023) Eduardo Ravelo-Nieto; Javier Cifuentes; Paola Ruiz Puentes; Laura Rueda-Gensini; Valentina Quezada; C. Ostos; Carolina Muñoz-Camargo; Luis H. Reyes; Alvaro Duarte‐Ruiz; Juan C. Cruz
The limited delivery of cargoes at the cellular level is a significant challenge for therapeutic strategies due to the presence of numerous biological barriers. By immobilizing the Buforin II (BUF-II) peptide and the OmpA protein on magnetite nanoparticles, a new family of cell-penetrating nanobioconjugates was developed in a previous study. We propose in this study to extend this strategy to silica nanoparticles (SNPs) and silanized fullerenol (F) as nanostructured supports for conjugating these potent cell-penetrating agents. The same molecule conjugated to distinct nanomaterials may interact with subcellular compartments differently. On the obtained nanobioconjugates (OmpA-SNPs, BUF-II-PEG12-SNPs, OmpA-F, and BUF-II-PEG12-F), physicochemical characterization was performed to evaluate their properties and confirm the conjugation of these translocating agents on the nanomaterials. The biocompatibility, toxicity, and internalization capacity of nanobioconjugates in Vero cells and THP-1 cells were evaluated in vitro. Nanobioconjugates had a high internalization capacity in these cells without affecting their viability, according to the findings. In addition, the nanobioconjugates exhibited negligible hemolytic activity and a low tendency to induce platelet aggregation. In addition, the nanobioconjugates exhibited distinct intracellular trafficking and endosomal escape behavior in these cell lines, indicating their potential for addressing the challenges of cytoplasmic drug delivery and the development of therapeutics for the treatment of lysosomal storage diseases. This study presents an innovative strategy for conjugating cell-penetrating agents using silica nanoparticles and silanized fullerenol as nanostructured supports, which has the potential to enhance the efficacy of cellular drug delivery.