A novel "reactomics" approach for cancer diagnostics.

Non-invasive detection and monitoring of lethal diseases, such as cancer, are considered as effective factors in treatment and survival. We describe a new disease diagnostic approach, denoted "reactomics", based upon reactions between blood sera and an array of vesicles comprising different lipids and polydiacetylene (PDA), a chromatic polymer. We show that reactions between sera and such a lipid/PDA vesicle array produce chromatic patterns which depend both upon the sera composition as well as the specific lipid constituents within the vesicles. The chromatic patterns were processed through machine-learning algorithms, and the bioinformatics analysis could distinguish both between cancer-bearing and healthy patients, respectively, as well between two types of cancers. Size-separation and enzymatic digestion experiments indicate that lipoproteins are the primary components in sera which react with the chromatic biomimetic vesicles. This colorimetric reactomics concept is highly generic, robust, and does not require a priori knowledge upon specific disease markers in sera. Therefore, it could be employed as complementary or alternative approach for disease diagnostics.

Lipoprotein interactions with chromatic membranes as a novel marker for oxidative stress-related diseases.

Changes in the abundance and properties of blood lipoproteins are generally considered major causes for varied pathological conditions and diseases. Using novel chromatic biomimetic vesicle and cell assays, we present here for the first time evidence for significant changes in lipoproteins' interactions with artificial membranes. Specifically, we demonstrate significant differences in membrane binding between lipoproteins (both low-density lipoprotein [LDL] and high-density lipoprotein [HDL]) harvested from diabetic patients vs. healthy controls as well as between oxidized and native lipoproteins. The chromatic assays, complemented by biophysical techniques and electron microscopy, point to significant reduction of surface membrane binding of the lipoproteins as a consequence of diabetes or oxidation. Overall, our results indicate that the substantial modulation of membrane interactions revealed by the chromatic assays may be used as a new and potentially powerful marker for screening and prediction of diseases associated with oxidative stress.