Anti-Tim4 Grafting Strongly Hydrophilic Metal–Organic Frameworks Immunoaffinity Flake for High-Efficiency Capture and Separation of Exosomes

Abstract

Exosomes have become the most ideal analysis target for liquid biopsy since they carry a large amount of genetic materials. The study on exosomes has great significance for cancer diagnosis and prognosis. However, the extremely low concentration renders the development of a robust exosomes enrichment technique, with the merits of low nonspecific cell adhesion, high-capture efficiency, and easy nondestructive release of captured exosomes, of vital significance. We successfully designed and developed a novel Tim4@ILI-01 immunoaffinity flake material. First, a strongly hydrophilic ILI-01 MOFs matrix material was fabricated with cationic ionic liquid 1,3-bis­(4-carboxybutyl)­imidazolium bromide as the organic ligand. The nonspecific adsorption of the ILI-01 MOFs material was only 0.7% after two washings with a neutral buffer. Moreover, based on the inherent abundant carboxyl groups on the ILI-01 MOFs flake, they can be facilely functionalized with an anti-Tim4 antibody with the bonding efficiency of 82.4%. The capture efficiency of the developed Tim4@ILI-01 immunoaffinity material for exosomes reached 85.2%, which is 5.2 times higher than that via the gold standard ultracentrifugation method. Furthermore, based on the Ca2+-dependent characteristic of the binding between the Tim4@ILI-01 immunoaffinity material and phosphatidylserine (PS) on the surfaces of exosomes, the captured exosomes can be easily released with the addition of a chelating agent under neutral eluent conditions. Thus, the captured exosomes maintained good biological activity. The developed Tim4@ILI-01 immunoaffinity flake was successfully applied for enrichment of exosomes from serums of healthy persons and lung adenocarcinoma patients. The levels of the expressed CD44 gene significantly changed under different stages of lung adenocarcinoma cancer. All these results demonstrate that the Tim4@ILI-01 immunoaffinity flake is a robust enrichment material and has a good potential in practical clinical applications.

Tailoring a multifunctional magnetic cationic metal–organic framework composite for synchronous enrichment of phosphopeptides/glycopeptides

“…In short, ILI and Fe 3 O 4 were prepared according to previous reports. 53,54 For the preparation of Fe 3 O 4 @ILI-01, 0.30 g of Fe 3 O 4 was dispersed into 10 mL of methanol (MeOH) containing 0.81 g of Zn(NO 3 ) 2 Á6H 2 O (27.2 mmol). The suspension solution was stirred at 70 1C for 1 h, and then 1.01 g of ILI (3.13 mmol) was introduced for the generation of ILI-01 on the surface of Fe 3 O 4 .…”

Progress in Nanomaterials-Based Optical and Electrochemical Methods for the Assays of Exosomes

“…In this detection principle, nanomaterials not only act as matric materials for exosomes capture, but also can amplify MS signal due to the large amount of elements in nanomaterials. [222][223][224][225][226][227] Recently, Zhang et al reported an ultrasensitive inductively coupled plasma−mass spectrometry (ICP-MS) method for the detection of exosomes by using UCNPs as element labels. 228 As shown in Figure 18, three different elements (Y, Eu, and Tb) doped UCNPs modified with three different aptamers were linked to AuNPs, forming three statellite-like nanoassemblies.…”

Recent Progress of Exosome Isolation and Peptide Recognition-Guided Strategies for Exosome Research

“…Magnetic beads immobilized with Tim4 can capture exosomes quickly, and intact exosomes can be easily eluted by chelating agent ( Xu et al, 2018 ). Zhang et al developed a novel Tim4@ILI-01 immunoaffinity flake material for the enrichment of exosomes from serum ( Figure 2A ; Zhang et al, 2021b ). The gene analysis of eluted exosomes showed that the level of the expressed CD44 gene was significantly high in lung adenocarcinoma patients.…”

“… (A) Schematic diagram of the membrane modified by fusion peptide-mediated exosomes. Reprinted with permission from Zhang et al, 2021b . (B) Protein ligating enzymes mediate a covalent conjugation of exosomes with peptides.…”