Search

Section S1: Quantification of Au(III) immobilized in tectomer by means of AuBr4− complex formation. (Table S1: Effect of the pH on AuBr4− complex formation. Figure S1: (a) Absorption spectra of AuBr4−; (b) Absorption spectra upon addition of KBr to a solution containing Au(III)/tectomer complex at pH 6.0 and 7.0; (c) Plot representing Au(III) concentration in the supernatant resulting from the addition of KBr in pH 2.0 buffer to Au(III)/tectomer layers on PLA supports. Table S2: Au(III) concentration in the supernatant resulting from the addition of KBr in pH 2.0 buffer to the Au(III)/tectomer layers on PLA supports. Table S3: Percentage of Au(III) released from the tectomer into the solution at pH 2.0.). Section S2: Optimization of experimental parameters for tyramine detection using Au(III)/tectomer sensor layers. (Figure S2: R coordinate as a function of the tyramine concentration for Au(III)/tectomer layers prepared using different pH buffers. Figure S3: R coordinate as a function of tyramine concentration for different Au(III)/tectomer molar ratios. Figure S4: Au(III)/tectomer sensing layer response to several tyramine concentrations at different pH values. Figure S5: R coordinate as a function of the pH of the buffers used to dissolve tyramine. [Tyramine] = 10 µM in all cases.). Section S3: Extraction method for the cheese samples.

Table S1: Atomic percentage of EVs isolated from cell cultures. Mean ± SD; Table S2: Nitrogen chemical environmental analysis of EVs isolated from cell cultures. Mean ± SD; Table S3: Percentage atomic composition of EVs isolated from female control donors (n = 6) and ovarian tumor patients of different tumor grades: I (n = 8), II (n = 1), III (n = 2) and IV (n = 7). Mean ± SD; Table S4: Nitrogen composition of EVs isolated from female control donors (n = 6) and ovarian tumor patients of different tumor grades: I (n = 8), II (n = 1), III (n = 2) and IV (n = 7). Mean ± SD; Table S5: Atomic composition of EVs isolated from healthy donors (n = 10) and pancreatic tumor patients (n = 10) at diagnosis. Mean ± SD; Table S6: Nitrogen composition of EVs isolated from healthy donors (n = 10) and pancreatic tumor patients (n = 10) at diagnosis. Mean ± SD.

The question of whether exosome lipids can be considered as potential cancer biomarkers faces our current limited knowledge of their composition. This is due to the difficulty in isolating pure exosomes, the variability of the biological sources from which they are extracted, and the uncertainty of the methods for lipid characterization. Here, we present a procedure to isolate exosomes and obtain a deep, repeatable, and rapid phospholipid (PL) composition of their lipid extracts, from embryonic murine fibroblasts (NIH-3T3 cell line) and none (B16-F1) and high (B16-F10) metastatic murine skin melanoma cells. The analytical method is based on High Performance Thin-Layer Chromatography with Ultraviolet and fluorescence densitometry and coupled to Electrospray (ESI)-tandem Mass Spectrometry (MS). Under the conditions described in this work, separation and determination of PL classes, (sphingomyelins, SM; phosphatidylcholines, PC; phosphatidylserines, PS; and phosphatidylethanolamines, PE) were achieved, expressed as µg PL/100 µg exosome protein, obtained by bicinchoninic acid assay (BCA). A detailed structural characterization of molecular species of each PL class was performed by simultaneous positive and negative ESI-MS and MS/MS directly from the chromatographic plate, thanks to an elution-based interface.