ORGANIC-INORGANIC NANOPARTICLES AS INTERNAL LIGHT SOURCES FOR LOCALIZED PHOTOPOLYMERIZATION OF MIP SHELLS: APPLICATION FOR CELL TARGETING AND IMAGING

We report a facile and generic strategy to synthesize core-shell molecularly imprinted polymer (MIP) nanocomposites. The method uses the UV or visible light emitted from upconverting NPs (UCNPs) or quantum dots (QDs) or carbon dots (CDs), upon excitation by near infrared or UV radiation respectively, to photopolymerize a MIP shell on their surface.^1-3 Since the emission from the core NPs is weak as compared to direct light, polymerization is confined to the cores’ surface and thus produces core-shell particles (Figure 1). The core-shell QD-MIP² and CD-MIP³ were applied for cell labeling and imaging of cancer biomarkers: hyaluronic acid (HA) and sialic acid (SA), on keratinocytes and human cervix adenocarcinoma (HeLa) cells. Glucuronic acid (GlcA), a substructure of HA and N-acetylneuraminic acid, the most common member of SA, were used as templates. The QD or CD have two main functionalities: (i) as an internal light source to trigger photopolymerization and (ii) as a fluorescent probe for bioimaging of cells specifically targeted by the MIP shell. The application of non-cytotoxic MIP-coated QDs/CDs as artificial receptors and imaging agents for glycosylation sites paves the way for new applications in diagnostics, theranostics, and therapeutics.

Figure 1. Illustrative example showing the application of internal visible light emitted from UV-excited fluorescent CD for the photopolymerization of a MIP shell around the CD. The core-shell nanocomposite is then applied for labeling and imaging hyaluronic acid on fixated HeLa cells.³

[1] Beyazit S., Ambrosini S., Marchyk N., Palo E., Kale V., Soukka T., Tse Sum Bui B., Haupt K. (2014) Versatile synthetic strategy for coating upconverting nanoparticles with polymer shells through localized photopolymerization by using the particles as internal light sources. Angew. Chem. Int. Ed. 53:8919-8923

[2] Panagiotopoulou M., Salinas Y., Beyazit S., Kunath S., Duma L., Prost E., Mayes A. G., Resmini M., Tse Sum Bui B., Haupt K. (2016) Molecularly imprinted polymer coated quantum dots for multiplexed cell targeting and imaging. Angew. Chem. Int. Ed. 55:1-6.

[3] Demir B., Lemberger M. M., Panagiotopoulou M., Medina Rangel P. X., Timur S., Hirsch T., Tse Sum Bui B., Wegener J., Haupt K. (2018) Tracking hyaluronan: Molecularly imprinted polymer coated carbon dots for cancer cell targeting and imaging. ACS Appl. Mater. Interfaces 10: 3305-3313.