Conformational Changes in High-Density Lipoprotein Nanoparticles Induced by High Payloads of Paramagnetic Lipids
Pedro Ramos-Cabrer1, Francois Fay2, Brenda L Sanchez-Gaytan2
1Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 Donostia-San Sebastián, Spain; Ikerbasque, Basque Foundation for Science, Maria Diaz de Haro 3, 48011 Bilbao, Spain; Clinical Neurosciences Research Laboratory, Department of Neurology, University Clinical Hospital Santiago, Health Sciences Institute (IDIS), Travesa da choupana s/n, 15706 Santiago de Compostela, Spain.
Abstract:
High-density lipoprotein (HDL) nanoparticles doped with gadolinium lipids can be used as magnetic resonance imaging diagnostic agents for atherosclerosis. In this study, HDL nanoparticles with different molar fractions of gadolinium lipids (0 < xGd-lipids < 0.33) were prepared, and the MR relaxivity values (r1 and r2) for all compositions were measured. Both r1 and r2 parameters reached a maximal value at a molar fraction of approximately xGd-lipids = 0.2. Higher payloads of gadolinium did not significantly increase relaxivity values but induced changes in the structure of HDL, increasing the size of the particles from dH = 8.2 ± 1.6 to 51.7 ± 7.3 nm. High payloads of gadolinium lipids trigger conformational changes in HDL, with potential effects on the in vivo behavior of the nanoparticles.
