tailieunhanh - Báo cáo hóa học: " The influence of colloidal parameters on the specific power absorption of PAA-coated magnetite nanoparticles"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: The influence of colloidal parameters on the specific power absorption of PAA-coated magnetite nanoparticles | Pineiro-Redondo et al. Nanoscale Research Letters 2011 6 383 http content 6 1 383 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access The influence of colloidal parameters on the specific power absorption of PAA-coated magnetite nanoparticles Yolanda Pineiro-Redondo 1 Manuel Banobre-Lopez1 Iván Pardinas-Blanco2 Gerardo Goya3 M Arturo Ldpez-Quintela1 and José Rivas1 Abstract The suitability of magnetic nanoparticles MNPs to act as heat nano-sources by application of an alternating magnetic field has recently been studied due to their promising applications in biomedicine. The understanding of the magnetic relaxation mechanism in biocompatible nanoparticle systems is crucial in order to optimize the magnetic properties and maximize the specific absorption rate SAR . With this aim the SAR of magnetic dispersions containing superparamagnetic magnetite nanoparticles bio-coated with polyacrylic acid of an average particle size of 10 nm has been evaluated separately by changing colloidal parameters such as the MNP concentration and the viscosity of the solvent. A remarkable decrease of the SAR values with increasing particle concentration and solvent viscosity was found. These behaviours have been discussed on the basis of the magnetic relaxation mechanisms involved. PaCs 80 87 Introduction Biocompatible magnetic nanoparticles MNPs are increasingly being used in many biomedical applications such as magnetic resonance imaging drug delivery cell and tissue targeting or hyperthermia 1-3 . For hyperthermia therapy nanotechnology offers a powerful tool to the design of nanometre heat-generating sources which can be activated remotely by the application of an external alternating magnetic field AMF . The magnetic energy absorption of nanoparticle-containing tissues induces a localized heating that allows a targeted cell death at a critical temperature above 42 to 45 C. This temperature increase can be used to selectively