National Nuclear Energy Commission

About: National Nuclear Energy Commission is a government organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Dosimetry & Laser. The organization has 3816 authors who have published 4694 publications receiving 59951 citations.

Synthesis and characterization of mesoporous silica/poly(N-isopropylacrylamide) functional hybrid useful for drug delivery

Abstract: Recent studies indicate the use of mesoporous silica and polymeric sensitive hydrogels as suitable for drug delivery systems due to their specific characteristics. Polymeric hydrogels, such as poly(N-isopropylacrylamide) [P(N-iPAAm)], show volumetric expansion/contraction behaviour at 306 K, which that can be used to develop a thermosensitive drug delivery system. In this study, we report a facile and direct synthesis route to obtain hybrid functional nanosystems based on silica-P(N-iPAAm) by using a neutral surfactant and without any functionalization method and the assessment of its release rate of a model drug. The materials were characterized by Fourier transform infrared spectroscopy, nitrogen adsorption, scanning electron microscopy, transmission electron microscopy and thermal analysis. A release assay with atenolol monitored by UV–Vis spectroscopy was performed for pure SBA-15 and a hybrid system at different temperatures in order to evaluate the influence of the thermosensitive behaviour of the polymer on the release kinetics. The response of the hybrid system as a drug delivery device is influenced by the volumetric contraction of P(N-iPAAm) up to the lower critical solution temperature (LCST) due to phase transition. Above the LCST, drug release depends essentially on the temperature.