RESUMEN
Silver nanoparticles (AgNPs) not only have shown remarkable results as antimicrobial and antiviral agents but also as antitumor agents. This work reports the complete characterization of five polyvinylpyrrolidone-coated AgNP (PVP-AgNP) formulations, their cytotoxic activity against human colon tumor cells (HCT-15), their cytotoxic effect on primary mouse cultures, and their lethal dose on BALB/c mice. The evaluated AgNP formulations have a composition within the ranges Ag: 1.14-1.32% w/w, PVP: 19.6-24.5% and H2O: 74.2-79.2% with predominant spherical shape within an average size range of 16-30 nm according to transmission electron microscopy (TEM). All formulations assessed increase mitochondrial ROS concentration and induce apoptosis as the leading death pathway on HCT-15 cells. Except for AgNP1, the growth inhibition potency of AgNP formulations of human colon tumor cancer cells (HCT-15) is 34.5 times higher than carboplatin, one of the first-line chemotherapy agents. Nevertheless, 5-10% of necrotic events, even at the lower concentration evaluated, were observed. The cytotoxic selectivity was confirmed by evaluating the cytotoxic effect on aorta, spleen, heart, liver, and kidney primary cultures from BALB/c mice. Despite the cytotoxic effects observed in vitro, the lethal dose and histopathological analysis showed the low toxicity of these formulations (all of them on Category 4 of the Globally Harmonized System of Classification and Labelling of Chemicals) and minor damage observed on analyzed organs. The results provide an additional example of the rational design of safety nanomaterials with antitumor potency and urge further experiments to complete the preclinical studies for these AgNP formulations.
RESUMEN
BACKGROUND: Laparoscopic surgery for colorectal cancer is currently accepted and widespread worldwide. However, according tol the surgical experience on this approach, surgical and short-term oncologic results may vary. Studies comparing laparoscopic vs. open surgery in our population are scarce. OBJECTIVE: To determine the superiority of the laparoscopic vs. open technique for colorectal cancer surgery. METHODS: This retrospective and comparative study collected data from patients operated on for colorectal cancer between 1999 and 2011 at the Angeles Lomas Hospital, Mexico. RESULTS: A total of 82 patients were included in this study; 47 were operated through an open approach and 35 laparoscopically. Mean operative time was significantly lower in the open approach group (p= 0.008). There were no significant difference between both techniques for intraoperative bleeding (p= 0.3980), number of lymph nodes (p= 0.27), time to initiate oral feeding (p= 0.31), hospital stay (p= 0.12), and postoperative pain (p= 0.19). Procedure-related complications rate and type were not significantly different in both groups (p= 0.44). Patients operated laparoscopically required significantly less analgesic drugs (p= 0.04) and less need for epidural postoperative analgesia (p= 0.01). CONCLUSIONS: Laparoscopic approach is as safe as the traditional open approach for colorectal cancer. Early oncological and surgical results confirm its suitability according to this indication.
Antecedentes: la cirugía laparoscópica para tratar pacientes con cáncer colorrectal ha sido ampliamente aceptada y difundida en todo el mundo. Sin embargo, dependiendo de la experiencia en este abordaje los resultados quirúrgicos y oncológicos a corto plazo pueden variar. En nuestra población existen pocos estudios que comparan los resultados de esta técnica con los de la cirugía abierta. Objetivos: determinar la superioridad de la técnica laparoscópica o abierta en cirugía de cáncer colorrectal. Material y métodos: estudio retrospectivo y comparativo de pacientes operados con técnica abierta o laparoscópica por cáncer de colon y recto entre 1999 y 2011 en nuestro centro. Resultados: se incluyeron 47 pacientes intervenidos de manera convencional y 35 por laparoscopia. El tiempo operatorio fue menor en el grupo de cirugía abierta (p= 0.008). No se encontraron diferencias en: sangrado intraoperatorio (p= 0.3980), número de ganglios resecados (p= 0.27), inicio de la vía oral (p= 0.31), tiempo de estancia hospitalaria (p= 0.12), y dolor referido por el paciente (p= 0.19). En el grupo de cirugía laparoscópica se requirieron menos dosis de analgésicos (p= 0.04) y menor necesidad de catéter epidural para analgesia postoperatoria (p= 0.01). Las tasas de morbilidad (p= 0.44) y mortalidad (p= 0.39) fueron similares en ambos grupos. Conclusiones: la cirugía laparoscópica es equiparable a la técnica abierta en cuanto a estándares oncológicos y resultados técnicos. Este trabajo demuestra que en nuestro hospital la cirugía laparoscópica en pacientes con cáncer de colon y recto es tan segura como la cirugía abierta.