Identification of atherosclerosis using aminolevulinic gold nanoparticle assay in fecal specimens

The atheromatous plaques exhibit an accumulation of protoporphyrin IX, or PpIX, which is transferred to the feces. In this work it was associated a precursor of the PpIX, the 5-aminolevulinic acid, ALA, with gold nanoparticles (ALA:AuNps). The objective was verify the possibility to use ALA:AuNPs as a diagnosis agent for atherosclerosis. ALA:AuNps were synthesized mixing ALA with Tetrachloroauric(III) acid in miliQ water solution followed by photoreduction with light from a Xenon lamp. A total of 22 Male New Zealand rabbits were divided into 3 groups: control group (CG) where animals received normal diet, control group with ALA (CGALA ) and Experimental Group with ALA:AuNPs ( EGALAAu ) in which the animals received a diet with 1% cholesterol. Measurements of the emission intensity of extracted porphyrins from the feces in the region between 575 and 725 nm were done. An increase in the feces porphyrin emission after ALA and ALA:AuNPs administration was observed.