Honeycomb-Shaped Supermacroporous Adsorbent Integrating Size-Exclusion and Selective Chemisorption Enables High-Efficiency Extraction and Analysis of Exosomes from Plasma.

As cell secretions, exosomes play an important role in disease diagnosis, but the extraction of high-purity exosomes from body fluids faces great challenges. To address this issue, this work creates an excellently selective adsorbent by modifying the zwitterionic polymer carrying choline phosphate on the surface of honeycomb-shaped supermacroporous silica, which integrates chemisorption and size-exclusion principles. The results indicate that the supermacropore with a thin pore wall allows exosomes to enter and thereby be adsorbed by the polymer via specific multivalent interaction and, meanwhile, excludes large cell debris and microvesicles. Moreover, the amphiphilic polymer can inhibit the adsorption of coexisting proteins. Taking advantage of these properties, the adsorbent can extract higher purity exosomes in a simpler way over "gold standard" ultracentrifugation and normal adsorbents. Furthermore, the in situ lysis of adsorbed exosomes simplifies the subsequent analysis and enhances the sensitivity. Consequently, 422 proteins are identified in the exosomes extracted from healthy human plasma, which is higher than that obtained by ultracentrifugation. For plasma from colorectal cancer patients, 62 upregulated and 165 downregulated proteins are identified and can be used as potential biomarkers. In conclusion, the adsorbent can serve as a platform for the high-efficiency extraction of exosomes in clinical diagnostic research.