Hetero-substituted derivative of PtPFPP for intracellular O2 sensing of mammalian cells

Abstract

Intracellular Optical Oxygen sensing is a convenient approach for monitoring and imaging molecular oxygen (O2) in biological samples, however existing intracellular O2-sensing probes still have some limitations. This study describes one new phosphorescent hetero-substituted derivative of Pt(II)-tetrakis(pentafluorophenyl)porphyrin (PtPFPP) obtained via two-step thiol click-chemistry. Particularly, thio-glucose (Glc) and thio-methyl-polyethylene-glycol (mPEG) moieties were covalently attached to the phosphorescent dye, producing the trans-di-glucosylated-di-PEGylated derivative PtGlc2PEG2 (trans). In a previous publication, we demonstrated the ability of these short PEG oligomers to drastically reduce the ability of the tetra- or tri-PEGylated conjugates to translocate across the cellular membrane. However, in this study, we show the capability of the trans-di-PEGylated-di-glucosylated conformation to allow intracellular staining and O2 sensing (IcO2) in murine embryonic fibroblasts (MEFs) mammalian cells.