Actividad citotóxica y antiproliferativa de un extracto rico en fucoidan de Lessonia trabeculata sobre células de adenocarcinoma mamario murino 4T1

Introducción. Los tumores neoplásicos se caracterizan por su invasividad y metástasis. Las células neoplásicas tienen heterogeneidad genética, por lo cual pueden desarrollar resistencia a los quimioterápicos. Por esta razón, las plantas continúan siendo una fuente importante de nuevos productos anticancerígenos. Objetivo. Evaluar la actividad citotóxica y antiproliferativa de un extracto rico en fucoidan de Lessonia trabeculata nativa (EFLt) sobre la línea celular de adenocarcinoma mamario murino, triple negativo 4T1. Métodos. La citotoxicidad y la IC50 se determinaron en monocapas de 4T1 empleando el reactivo MTT. Para demostrar la actividad antiproliferativa se aplicaron los métodos de cierre de herida y anticlonogénico utilizando las IC50 del EFLt y Dox (doxorubicina). El cierre de herida fue evaluado mediante barrido de tiempos discretos; el efecto anticlonogénico fue evaluado 7 días postratamiento mediante el conteo de colonias y se determinó la fracción de sobrevivencia. Adicionalmente, se evaluaron la citotoxicidad y actividad antiproliferativa combinando las IC50 de EFLt y Dox. El porcentaje de migración y conteo de colonias se realizó con el programa ImageJ. Resultados. La IC50 del EFLt (950 μg/mL) produjo 56% de citotoxicidad, 80,3% de inhibición de la migración celular, 68% de inhibición en la formación de colonias. La IC50 de Dox fue 0,5 μg/mL. Conclusiones. El EFLt ejerce citotoxicidad dependiente de la concentración y tiene efecto antiproliferativo sobre 4T1. Se requiere continuar los ensayos en modelos de mayor complejidad que permitan esclarecer el potencial antitumoral del EFLt.

Introduction. Neoplastic tumors are characterized by invasiveness and metastasis. Neoplastic cells are genetically heterogeneous and can develop resistance to chemotherapeutic agents. For this reason, plants continue to be an important source of new anticancer products. Objective. To determine the cytotoxic and antiproliferative activity of a fucoidan-rich extract of native Lessonia trabeculata (EFLt) on the tripe negative murine mammary adenocarcinoma cell line 4T1. Methods. Cytotoxicity and IC50 were determined in 4T1 monolayers using the MTT reagent. To demonstrate antiproliferative activity, "wound" closure and anticlonogenic methods were applied using the IC50 of EFLt and Doc (doxorubicin). "Wound" closure was evaluated by discrete times sweep to determine percentage inhibition of cell migration; the anticlonogenic effect was evaluated by colony counting 7 days after treatment and the survival fraction was determined. In addition, cytotoxicity and antiproliferative activity were evaluated by combining the IC50 of EFLt and Dox. Percent migration and colony counts were performed using ImageJ software. Results. The IC50 (950 μg/mL) of EFLt was 56% cytotoxicity, 80,3% inhibition of cell migration, 68% inhibition of colony formation.The ICof Dox was 0,5 μg/mL. Conclusions. EFLt exerts concentration-dependent cytotoxicity and antiproliferative effect on 4T1. Further studies in more complex models are needed to elucidate the anti-tumor potential of EFLt.

Development and Characterization of PLGA-Based Multistage Delivery System for Enhanced Payload Delivery to Targeted Vascular Endothelium.

Vascular-targeted drug delivery remains an attractive platform for therapeutic and diagnostic interventions in human diseases. This work focuses on the development of a poly-lactic-co-glycolic-acid (PLGA)-based multistage delivery system (MDS). MDS consists of two stages: a micron-sized PLGA outer shell and encapsulated drug-loaded PLGA nanoparticles. Nanoparticles with average diameters of 76, 119, and 193 nm are successfully encapsulated into 3-6 µm MDS. Sustained in vitro release of nanoparticles from MDS is observed for up to 7 days. Both MDS and nanoparticles arebiocompatible with human endothelial cells. Sialyl-Lewis-A (sLeA ) is successfully immobilized on the MDS and nanoparticle surfaces to enable specific targeting of inflamed endothelium. Functionalized MDS demonstrates a 2.7-fold improvement in endothelial binding compared to PLGA nanoparticles from human blood laminar flow. Overall, the presented results demonstrate successful development and characterization of MDS and suggest that MDS can serve as an effective drug carrier, which can enhance the margination of nanoparticles to the targeted vascular wall.

Methylene blue-filled biodegradable polymer particles as a contrast agent for optical coherence tomography.

Optical coherence tomography (OCT) images largely lack molecular information or molecular contrast. We address that issue here, reporting on the development of biodegradable micro and nano-spheres loaded with methylene blue (MB) as molecular contrast agents for OCT. MB is a constituent of FDA approved therapies and widely used as a dye in off-label clinical applications. The sequestration of MB within the polymer reduced toxicity and improved signal strength by drastically reducing the production of singlet oxygen and leuco-MB. The former leads to tissue damage and the latter to reduced image contrast. The spheres are also strongly scattering which improves molecular contrast signal localization and enhances signal strength. We demonstrate that these contrast agents may be imaged using both pump-probe OCT and photothermal OCT, using a 830 nm frequency domain OCT system and a 1.3 µm swept source OCT system. We also show that these contrast agents may be functionalized and targeted to specific receptors, e.g. the VCAM receptor known to be overexpressed in inflammation.

Tratamiento endovascular exitoso del síndrome de cascanueces con stent autoexpandible / Successful endovascular treatment of nutcracker's syndrome with self-expanding stent

El síndrome de cascanueces (nutcracker's syndrome) se produce por compresión de la vena renal izquierda a su paso por la horquilla vascular, formada por la aorta y la arteria mesentérica superior, causando una compresión extrínseca que genera estenosis funcional de la misma. Esto produce congestión e hipertensión de la vena renal izquierda que se traduce en insuficiencia y várices de la vena gonadal izquierda, hematuria unilateral y dolor lumbar izquierdo, el diagnóstico pocas veces se realiza, por su baja frecuencia y por la falta de sospecha clínica. El tratamiento del síndrome de cascanueces incluye el autotransplante renal, trasposición de arteria mesentérica superior, revascularización y más recientemente, la colocación de stent en la vena renal. Presentamos el caso de un paciente que fue sometido a tratamiento endovascular exitoso con un stent autoexpandible en la vena renal izquierda, con criterios inmediatos de éxito por angiografía, reducción de la congestión venosa y por desaparición del gradiente cavo/renal.

Nutcracker's syndrome is caused by compression of the left renal vein between aorta and superior mesenteric artery, causing extrinsic compression generated functional stenosis. This causes congestion and hypertension of the left renal vein resulting in insufficiency and left gonadal vein varicose, unilateral hematuria and left flank pain, diagnosis is rarely identified by their low frequency and difficulty of suspecting, treatment of nutcracker's syndrome include renal autotransplantation, transposition of superior mesenteric artery revascularization and recently stenting in renal vein, we present the case of a patient, who showed this pathology by diagnostic support by image studies, was performed successfully implant a self-expanding stent with immediate success criteria by angiography, collateral reduction and by disappearance of cava/renal gradient.

[Successful endovascular treatment of nutcracker's syndrome with self-expanding stent]. / Tratamiento endovascular exitoso del síndrome de cascanueces con stent autoexpandible.

Nutcracker's syndrome is caused by compression of the left renal vein between aorta and superior mesenteric artery, causing extrinsic compression generated functional stenosis. This causes congestion and hypertension of the left renal vein resulting in insufficiency and left gonadal vein varicose, unilateral hematuria and left flank pain, diagnosis is rarely identified by their low frequency and difficulty of suspecting, treatment of nutcracker's syndrome include renal autotransplantation, transposition of superior mesenteric artery revascularization and recently stenting in renal vein, we present the case of a patient, who showed this pathology by diagnostic support by image studies, was performed successfully implant a self-expanding stent with immediate success criteria by angiography, collateral reduction and by disappearance of cava/renal gradient.