Cell surface imaging and bioorthogonal chemistry
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ZhangS_2021.pdf (9.563Mb)
Date
31/07/2021Author
Zhang, Shuo
Metadata
Abstract
The labelling of the plasma membrane with targeted fluorescent probes offers a
convenient and non-invasive means to image the cell membrane and follow
morphological changes and dynamics in real-time. However, despite many examples
of fluorescent plasma membrane probes, a “universal targeting/anchoring moiety” is
still required. In the first research section of my PhD, I report on the development of a
small library of stearic acid-based probes, labelled with 6-carboxyfluorescein, via
solid-phase synthesis, in which variation in both charge and hydrophobicity were
explored. An optimal probe was discovered that carried both a positively charged
amino group and a stearic acid tail that exhibited intense plasma membrane
brightness and robust retention.
In the second section of my PhD thesis, I investigated a light-driven, reversible
addition−fragmentation chain-transfer (photo-RAFT) polymerisation with a newly
developed fluorophore-conjugated RAFT agent, containing a BODIPY dye attached
to a thiocarbonylthio group. This new RAFT agent enabled light-controlled (470 nm)
“on/off” polymerisation, producing well-defined polymers, with excellent photostability.
It provides an expedient route to homogeneous fluorescently-labelled polymers.
In the third part of my PhD thesis, I discovered amphiphilic polymer-based fluorescent
probes which showed long-term plasma membrane binding, and that allowed imaging
and simultaneous functionalisation of the cell surface with azides, as shown by
fluorophore attachment via cycloaddition chemistry. The polymer structure was
optimised using a library approach.