Porous silicon nanoparticles as biocompatible contrast agents for magnetic resonance imaging

• DOI: 10.1063/1.4937731
• Publication Date: 2015-12-10T19:37:10Z
• Authors: M. B. Gongalsky; Yu. V. Kargina; L. A. Osminkina; A. M. Perepukhov; M. V. Gulyaev; A. N. Vasiliev; Yu. A. Pirogov; A. V. Maximychev; V. Yu. Timoshenko
• Keywords: 02 engineering and technology; 0210 nano-technology

We propose porous silicon nanoparticles (PSi NPs) with natural oxide coating as biocompatible and bioresorbable contrast agents for magnetic resonant imaging (MRI). A strong shortening of the transversal proton relaxation time (T2) was observed for aqueous suspensions of PSi NPs, whereas the longitudinal relaxation time (T1) changed moderately. The longitudinal and transversal relaxivities are estimated to be 0.03 and 0.4 l/(g·s), respectively, which are promising for biomedical studies. The proton relaxation is suggested to undergo via the magnetic dipole-dipole interaction with Si dangling bonds on surfaces of PSi NPs. MRI experiments with phantoms have revealed the remarkable contrasting properties of PSi NPs for medical diagnostics.