Lipopolysaccharide\nImprinted Polymers for Specific\nRecognition of Bacterial Outer Membrane Vesicles

Outer membrane vesicles (OMVs) secreted\nby bacteria are emerging\ndiagnostic markers for bacterial infection or disease detection due\nto their carriage of various signaling molecules. However, actual\nbiological samples of patients are extremely complex, and applying\nOMVs to clinical diagnosis remains a major challenge. One of the major\nchallenges is that there are still great difficulties in the enrichment\nof OMVs including tedious steps and lower concentration. And some\ncommonly used exosome enrichment methods, such as ultracentrifugation,\nstill have some shortcomings. Herein, we introduce lipopolysaccharide\n(LPS) molecularly imprinted polymer (MIP) for efficient capturing\nand analyzing OMVs, enabling a novel approach to bacterial disease\ndiagnosis based on biorecognition materials. LPS, as a unique structure\nof Gram-negative bacteria, also widely expressed on the surface of\nOMVs, which will form cyclic hydrogen bonds with functional monomers\nof MIP with affinity interactions. The prepared MIP efficiently can\nisolate OMVs from 100 μL of culture broth via specific affinity\nLPS in less than 40 min with a recovery rate of over 95%. Moreover,\nMIP exhibits good reusability, with almost identical enrichment performance\nafter 5 repeated cycles, contributing to reducing experimental costs\nin both time and economy. The captured OMVs can be detected using\nWestern blotting with target protein antibodies or in combination\nwith proteomic analysis, providing a proteomic biomarker platform\nfor early bacteria disease diagnosis.