RESUMEN
Nowadays, nanomedicine brings new opportunities for diagnosis and treatment through innovative combinations of materials structured at the nanoscale, biomolecules and physicochemical processes. If the intrinsic properties of nanomaterials appear of major importance in this new discipline, the functionalization of these nanotools with biomolecules improves both their biocompatibility and efficacy. This is the case of carbohydrate derivatives, natural or synthetic, which are increasingly being used in nanostructures for medical purposes. As in current medicine, sugars are used to mimic their physiological roles. Indeed, carbohydrates enhance the solubility and reduce the clearance of drugs. They are used to mask immunogenic components of nano-objects and escape the body defenses and finally facilitate the delivery to the target tissue. All these properties explain the growing importance of sugars in nanomedicine.
Asunto(s)
Antineoplásicos , Carbohidratos , Portadores de Fármacos , Nanomedicina/métodos , Animales , Antineoplásicos/química , Carbohidratos/química , Portadores de Fármacos/química , HumanosRESUMEN
In this mini-review, we focus on different strategies to bring nanotools specifically to cancer cells. We discuss about a better targeting of tumor, combining the characteristics of tumor environment, the increase in nanoparticles life time, the biomarkers overexpressed on cancer cells and different physical methods for non invasive therapies. Here we detail the necessity of a synergy between passive and active targeting for an actual specificity of cancer cells.
Asunto(s)
Antineoplásicos/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/análisis , Neoplasias/tratamiento farmacológico , Animales , Humanos , Neoplasias/irrigación sanguínea , Neoplasias/metabolismo , Oxígeno/metabolismo , Microambiente TumoralRESUMEN
Two mRNAs are transcribed from the extracellular matrix protein 1 gene (Ecm1): Ecm1a and an alternatively spliced Ecm1b. We studied Ecm1 mRNA expression and localization during endochondral bone formation and investigated the effect of recombinant human (rh) Ecm1a protein on organ cultures of embryonic mouse metatarsals. Of the two transcripts, Ecm1a mRNA was predominantly expressed in fetal metacarpals from day 16 to 19 after gestation. Ecm1 expression was not found in 16- and 17-day-old metatarsals of which the perichondrium was removed. In situ hybridization and immunohistochemistry demonstrated Ecm1 expression in the connective tissues surrounding the developing bones, but not in the cartilage. Biological effects of rhEcm1a protein on fetal metatarsal cultures were biphasic: at low concentrations, Ecm1a stimulated alkaline phosphatase activity and had no effect on mineralization, whereas at higher concentrations, Ecm1a dose dependently inhibited alkaline phosphatase activity and mineralization. These results suggest that Ecm1a acts as a novel negative regulator of endochondral bone formation.
Asunto(s)
Fosfatasa Alcalina/metabolismo , Calcificación Fisiológica/fisiología , Proteínas de la Matriz Extracelular/metabolismo , Huesos Metatarsianos/metabolismo , Animales , Radioisótopos de Calcio , Diferenciación Celular/fisiología , Condrocitos/química , Condrocitos/citología , Condrocitos/enzimología , Proteínas de la Matriz Extracelular/análisis , Proteínas de la Matriz Extracelular/genética , Miembro Anterior/embriología , Regulación del Desarrollo de la Expresión Génica/fisiología , Humanos , Huesos Metatarsianos/citología , Huesos Metatarsianos/embriología , Ratones , Comunicación Paracrina/fisiología , ARN Mensajero/análisis , Proteínas Recombinantes/metabolismoRESUMEN
Three new angiographic features of cholangiocarcinoma are bile duct dilatation, venous obstruction and arterio-arterial collaterals. Differentiation of the lucencies of dilated bile ducts (cylindrical in shape) from those due to metastases (spherical) is discussed. Because of its high reliability and the difficulties of operative diagnosis, angiography can play an important diagnostic role in patients with suspected cholangiocarcinoma.