A Membrane‐Bound Synthetic Receptor that Promotes Growth of a Polymeric Coating at the Bilayer–Water Interface

Abstract

Primed for action: Atom-transfer radical polymerization (ATRP) can be promoted at a bilayer-water interface by anchoring initiator molecules (see scheme; red) in a membrane-bound synthetic receptor (yellow). The bilayer is formed on a calcinated nanofilm (gray) on a gold surface.

Cell and Protein Recognition at a Supported Bilayer Interface via In Situ Cavitand-Mediated Functional Polymer Growth

“…Full, consistent surface coverage can be obtained by polymerization of polyHEMA or polyMMA (see below). 23 The small size of the polyAEMA patches, and their variability in size from experiment to experiment are consistent with inefficient, monomer-terminated ATRP. It is also possible that the reaction with the water-sensitive NBD-Cl does not occur at full conversion, although a large excess was used for testing.…”

“…23 Deep cavitands such as 1 (Figure 1) are lipophilic, and can incorporate in lipid bilayers while retaining their host abilities. 24–27 The most strongly binding guests for cavitands such as 1 are trimethylammonium species such as acetylcholine.…”

“…23 Whereas simple unfunctionalized monomers such as HEMA and methyl methacrylate (MMA) gave controllable polymer growth at the interface, larger monomers suffered from insolubility problems in buffered aqueous solution. Highly water-soluble saccharide-linked methacrylates showed weaker affinity for the cavitands in the bilayer and are easily washed from the surface.…”

“…This small guest causes only a slight change in resonance angle, consistent with that of other similarly sized guests. 23,24 The initiator is mildly reactive to water, so polymerization is performed within 5 min of injection.…”

Selective Cavitand-Mediated Endocytosis of Targeted Imaging Agents into Live Cells

“…These species are capable of molecular recognition and reaction promotion at the bilayer interface. 10 Their application has been limited to biomimetic constructs; little is known about their behavior in living cells. 7 Here we show that synthetic host molecules can be incorporated in living eukaryotic cell membranes and transport suitable targets across the cell membrane into the cell interior via “cavitand-mediated endocytosis”.…”