Gadopentetic Acid-doped Mesoporous Silica Nanoparticles As A Novel MRI Contrast Agent:Synthesis,Characterization And MRI Study

Purpose To synthesize a high gadopentetic acid(GA)doped mesoporous silica nano spheres(Gd-MSN)with a potential molecular target imaging as a novel MRI contrast agent.Materials and Methods A reverse microemulsion method was used to dope gadopentetic acid(GA)into the mesopores of mesoporous silica nanoparticles(MSN)to synthesize,for the first time,novel Gd-MSN with high gadolinium contents(GCs).These Gd-MSN were characterized using transmission electron microscopy(TEM)and a Malvern Zetasizer.The GCs and stability of the Gd-MSN were determined by inductively coupled plasma-atomic emission spectrometry(ICP-AES).The cell viability was tested with the Cell Counting Kit-8(CCK-8)assay.Finally,cellular and rat MRI was performed to determine the in vitro and in vivo MR enhancement effects of the Gd-MSN.Results Our results indicated that the globular Gd-MSN had high GCs,an average size of 105-128 nm,and good stability in a simulated in vitro environment.No significant cellular toxicity was observed in either normal or cancer cells at Gd-MSN concentrations of 25,50,and 100 ?g/m L.The cellular and rat MRI demonstrated that the Gd-MSN had strong MR enhancement effects both in vitro and in vivo.Gd-MSN with high Gadolinium content of 771.08?mo L/g was synthesized.MRI showed that Gd-MSN can significantly shorten the T1 and T2 relaxation time.Gd-MSN showed short T1 and short T2 signal features.Conclusion The successful preparation of the Gd-MSN,which was monodisperse,easy to modify and has high GC,is expected to become a novel multifunctional targeted highly efficient MRI nano contrast agent.