A Microchambers Containing Contact Lens for the Noninvasive Detection of Tear Exosomes

Exosomes, a form of small extracellular vesicles, play a crucial role in the metastasis of cancers and thus are investigated as potential biomarkers for cancer diagnosis. However, conventional detection methods like immune-based assay and microRNA analyses are expensive and require tedious pretreatments and lengthy analysis time. Since exosomes related to cancers are reported to exist in tears, a poly(2-hydroxyethyl methacrylate) contact lens embedded with antibody-conjugated signaling microchambers (ACSM-PCL) capable of detecting tear exosomes is reported. The ACSM-PCL exhibits high optical transparency and mechanical properties, along with extraordinary biocompatibility and good sensitivity to exosomes. A gold nanoparticle colorimetric assay is employed to visualize captured exosomes. The ACSM-PCL can detect exosomes in the pH range of 6.5-7.4 (similar to the human tear pH) and have a strong recovery yield in bovine serum albumin solutions. In particular, the ACSM-PCL can detect exosomes in various solutions, including regular buffer, cell culture media from various cell lines, and human tears. Finally, the ACSM-PCL can differentiate expression of exosome surface proteins hypothesized as cancer biomarkers. With these encouraging results, this ACSM-PCL is promised to be the next generation smart contact lens as an easy-to-use, rapid, noninvasive monitoring platform of cancer pre-screening and supportive diagnosis.