Behavior of the thermal diffusivity of native and oxidized human low-density lipoprotein solutions studied by the Z-scan technique


Autoria(s): Santos, Priscila Ribeiro dos; Genaro-Mattos, Thiago C.; Monteiro, Andrea Moreira; Miyamoto, Sayuri; Figueiredo Neto, Antonio Martins
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

07/11/2013

07/11/2013

2012

Resumo

Modifications in low-density lipoprotein (LDL) have emerged as a major pathogenic factor of atherosclerosis, which is the main cause of morbidity and mortality in the western world. Measurements of the heat diffusivity of human LDL solutions in their native and in vitro oxidized states are presented by using the Z-Scan (ZS) technique. Other complementary techniques were used to obtain the physical parameters necessary to interpret the optical results, e. g., pycnometry, refractometry, calorimetry, and spectrophotometry, and to understand the oxidation phase of LDL particles. To determine the sample's thermal diffusivity using the thermal lens model, an iterative one-parameter fitting method is proposed which takes into account several characteristic ZS time-dependent and the position-dependent transmittance measurements. Results show that the thermal diffusivity increases as a function of the LDL oxidation degree, which can be explained by the increase of the hydroperoxides production due to the oxidation process. The oxidation products go from one LDL to another, disseminating the oxidation process and caring the heat across the sample. This phenomenon leads to a quick thermal homogenization of the sample, avoiding the formation of the thermal lens in highly oxidized LDL solutions. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JBO.17.10.105003]

National Counsel for Scientific and Technological Development (CNPq)

National Counsel for Scientific and Technological Development (CNPq)

Sao Paulo Research Foundation (FAPESP)

Sao Paulo Research Foundation (FAPESP)

National Institute of Science and Technology of Complex Fluid (INCTFCx)

National Institute of Science and Technology of Complex Fluid (INCT-FCx)

Redoxoma (INCT-Redoxoma)

Redoxoma (INCTRedoxoma)

Identificador

JOURNAL OF BIOMEDICAL OPTICS, BELLINGHAM, v. 17, n. 10, supl. 1, Part 1, pp. 3825-3834, OCT, 2012

1083-3668

http://www.producao.usp.br/handle/BDPI/42851

10.1117/1.JBO.17.10.105003

http://dx.doi.org/10.1117/1.JBO.17.10.105003

Idioma(s)

eng

Publicador

SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS

BELLINGHAM

Relação

JOURNAL OF BIOMEDICAL OPTICS

Direitos

openAccess

Copyright SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS

Palavras-Chave #LOW DENSITY LIPOPROTEIN #OXIDATION #Z-SCAN #THERMAL-LENS #HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY #THERMAL DIFFUSIVITY #OXIDATIVE MODIFICATION #SINGLE-BEAM #DISEASE #LDL #ATHEROSCLEROSIS #BIOCHEMICAL RESEARCH METHODS #OPTICS #RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING
Tipo

article

original article

publishedVersion