Structural and Nonlinear Optical Characteristics of In Vitro Glycation of Human Low-Density Lipoprotein,as a Function of Time

Modified low-density lipoprotein (LDL) is a well-known risk marker for diabetes and cardiovascular disease. In vitro and in vivo studies have shown that native LDL particles, when modified by oxidation and/or glycation processes, become proatherogenic. Other studies have shown that high LDL concentrations also contribute to atherogenic diseases. In the present in vitro study, we investigate structural characteristics, linear and nonlinear optical properties of LDL particles modified by glycation, compared to modified-control and non-modified LDL (LDL_nat). LDL particles were isolated from normolipidemic individuals and aliquots were incubated in PBS (LDL_control) and glycated (LDL_glyc) with glycolaldehyde (GAD) from 2 to 6 days. The nonlinear optical Z-Scan experiments indicate that GAD modifies the optical properties of the LDL. These results indicate the application of a nonlinear optical technique as a tool to investigate the characteristics of LDL particles, in particular when modifications are induced in the particles by glycation.