Cylindrical
block copolymer micelles have shown considerable promise
in various fields of biomedical research. However, unlike spherical
micelles and vesicles, control over their dimensions in biologically
relevant solvents has posed a key challenge that potentially limits
in depth studies and their optimization for applications. Here, we
report the preparation of cylindrical micelles of length in the wide
range of 70 nm to 1.10 μm in aqueous media with narrow length
distributions (length polydispersities <1.10). In our approach,
an amphiphilic linear-brush block copolymer, with high potential for
functionalization, was synthesized based on poly(ferrocenyldimethylsilane)-<i>b</i>-poly(allyl glycidyl ether) (PFS-<i>b</i>-PAGE)
decorated with triethylene glycol (TEG), abbreviated as PFS-<i>b</i>-(PEO-<i>g</i>-TEG). PFS-<i>b</i>-(PEO-<i>g</i>-TEG) cylindrical micelles of controlled length with low
polydispersities were prepared in <i>N</i>,<i>N</i>-dimethylformamide using small seed initiators via living crystallization-driven
self-assembly. Successful dispersion of these micelles into aqueous
media was achieved by dialysis against deionized water. Furthermore,
B–A–B amphiphilic triblock comicelles with PFS-<i>b</i>-poly(2-vinylpyridine) (P2VP) as hydrophobic “B”
blocks and hydrophilic PFS-<i>b</i>-(PEO-<i>g</i>-TEG) “A” segments were prepared and their hierarchical
self-assembly in aqueous media studied. It was found that superstructures
formed are dependent on the length of the hydrophobic blocks. Quaternization
of P2VP was shown to cause the disassembly of the superstructures,
resulting in the first examples of water-soluble cylindrical multiblock
comicelles. We also demonstrate the ability of the triblock comicelles
with quaternized terminal segments to complex DNA and, thus, to potentially
function as gene vectors