TY - JOUR
T1 - Particle size measurement of lipoprotein fractions using diffusion-ordered NMR spectroscopy
AU - Mallol, Roger
AU - Rodríguez, Miguel A.
AU - Heras, Mercedes
AU - Vinaixa, Maria
AU - Plana, Núria
AU - Masana, Lluís
AU - Morris, Gareth A.
AU - Correig, Xavier
N1 - Funding Information:
Acknowledgments We acknowledge CIBER de Diabetes y Enfermedades Metabólicas Asociadas (ISCIII, Ministerio de Ciencia e Innovación), for partially funding this work, as well as the FIS (project PI 081409). This work was partly supported by the Engineering and Physical Sciences Research Council (Grant Numbers EP/H024336/1 and EP/I007989/1). We also acknowledge Dr. M. Moncusí and Dr. R. Marimon for their assistance with the TEM analysis of the lipoprotein fractions as well as Dr. S. Pujol for her assistance with viscosity measurements.
PY - 2012/3
Y1 - 2012/3
N2 - The sizes of certain types of lipoprotein particles have been associated with an increased risk of cardiovascular disease. However, there is currently no gold standard technique for the determination of this parameter. Here, we propose an analytical procedure to measure lipoprotein particles sizes using diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY). The method was tested on six lipoprotein fractions, VLDL, IDL, LDL 1, LDL 2, HDL 2, and HDL 3, which were obtained by sequential ultracentrifugation from four patients. We performed a pulsed-field gradient experiment on each fraction to obtain a mean diffusion coefficient, and then determined the apparent hydrodynamic radius using the Stokes-Einstein equation. To validate the hydrodynamic radii obtained, the particle size distribution of these lipoprotein fractions was also measured using transmission electron microscopy (TEM). The standard errors of duplicate measurements of diffusion coefficient ranged from 0.5% to 1.3%, confirming the repeatability of the technique. The coefficient of determination between the hydrodynamic radii and the TEM-derived mean particle size was r 2∈=∈0.96, and the agreement between the two techniques was 85%. Thus, DOSY experiments have proved to be accurate and reliable for estimating lipoprotein particle sizes. [Figure not available: see fulltext.]
AB - The sizes of certain types of lipoprotein particles have been associated with an increased risk of cardiovascular disease. However, there is currently no gold standard technique for the determination of this parameter. Here, we propose an analytical procedure to measure lipoprotein particles sizes using diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY). The method was tested on six lipoprotein fractions, VLDL, IDL, LDL 1, LDL 2, HDL 2, and HDL 3, which were obtained by sequential ultracentrifugation from four patients. We performed a pulsed-field gradient experiment on each fraction to obtain a mean diffusion coefficient, and then determined the apparent hydrodynamic radius using the Stokes-Einstein equation. To validate the hydrodynamic radii obtained, the particle size distribution of these lipoprotein fractions was also measured using transmission electron microscopy (TEM). The standard errors of duplicate measurements of diffusion coefficient ranged from 0.5% to 1.3%, confirming the repeatability of the technique. The coefficient of determination between the hydrodynamic radii and the TEM-derived mean particle size was r 2∈=∈0.96, and the agreement between the two techniques was 85%. Thus, DOSY experiments have proved to be accurate and reliable for estimating lipoprotein particle sizes. [Figure not available: see fulltext.]
KW - DOSY
KW - Lipoprotein
KW - NMR
KW - TEM
UR - http://www.scopus.com/inward/record.url?scp=84859110427&partnerID=8YFLogxK
U2 - 10.1007/s00216-011-5705-9
DO - 10.1007/s00216-011-5705-9
M3 - Article
C2 - 22293969
AN - SCOPUS:84859110427
SN - 1618-2642
VL - 402
SP - 2407
EP - 2415
JO - Analytical and Bioanalytical Chemistry
JF - Analytical and Bioanalytical Chemistry
IS - 7
ER -
