Physicochemical properties of ionic and non-ionic biocompatible hydrogels in water and cell culture conditions: Relation with type of morphologies of bovine fetal fibroblasts in contact with the surfaces.

Cationic, anionic and non-ionic hydrogels having acrylamide polymer backbones were synthesized via free radical polymerization with N,N-methylenebisacrylamide (BIS) as crosslinker. The chemical structures of the hydrogels were characterized by Fourier Transform Infrared Spectroscopy (FTIR). Physicochemical properties such as swelling kinetic, maximum swelling capacity, volume phase transition temperature (VPTT) and wettability (static water contact angle) of hydrogels swollen in aqueous and cell culture medium, at room and cell culture temperatures were studied. In order to correlate the surface properties of the hydrogels and cellular adhesivity of bovine fetal fibroblasts (BFFs), cellular behaviour was analyzed by inverted fluorescence optical microscopy and atomic force microscopy (AFM). MTT assay demonstrated that the number of viable cells in contact with hydrogels does not significantly change in comparison to a control surface. Flattened and spindle-shaped cells and cell spheroids were the adopted morphologies during first days of culture on different hydrogels. Cell spheroids were easily obtained during the first 5days of culture in contact with PNIPAM-co-20%HMA (poly (N-isopropylacrylamide-co-20%N-acryloyl-tris-(hydroxymethyl)aminomethane)) hydrogel surface. After 15days of culture all hydrogels showed high adhesion and visual proliferation. According to obtained results, non-ionic and hydrophilic surfaces with moderated wettability induce the formation of BFFs cell spheroids. These hydrogel surfaces could be used in clinical and biochemical treatments at laboratory level to cell growth and will allow generating the base for future biotechnologic platform.

Vitamina D y cáncer / Cancer and vitamin D

El cáncer es una de las mayores causas de muerte en el mundo. Si bien la vitamina D (colecalciferol) ha sido asociada a la regulación de la homeostasis de calcio, muchos son los datos epidemiológicos, bioquímicos y genéticos sobre otros efectos importantes de la vitamina D, como el desarrollo y la progresión de diferentes cánceres. El objetivo del presente artículo es revisar distintos aspectos acerca de los mecanismos de acción y efectos moleculares de la vitamina D o sus metabolitos y de los indicadores epidemiológicos que los correlacionan con el cáncer, su prevención y tratamiento. El estudio de los efectos de la vitamina D se ha vuelto muy amplio: nuevos genes, nuevos blancos, mecanismos diferentes. Niveles adecuados de vitamina D son necesarios para una gran cantidad de procesos fisiológicos y no solamente para el mantenimiento de la homeostasis del calcio. Los estudios clínicos podrían revisar las recomendaciones sobre las dosis de vitamina D que puedan proteger también contra el desarrollo del cáncer.