Spherical nucleic acids have emerged as a class of nanostructures,
exhibiting a wide variety of properties, distinctly different from
those of linear nucleic acids, and a plethora of applications in therapeutics
and diagnostics. Herein, we report on preparation of 3D nucleic acid
nanostructures, prepared by self-assembly of polymer–oligonucleotide
conjugates. The latter are obtained by grafting multiple alkyne-functionalized
oligonucleotide strands onto azide-modified homo-, block, and random
(co)polymers of chloromethylstyrene via initiator-free click coupling
chemistry to form conjugates of comblike and coil-comb chain architectures.
The resulting conjugates are amphiphilic and form stable nanosized
supramolecular structures in aqueous solution. The nanoconstructs
are thoroughly investigated and a number of physical characteristics,
in particular, molar mass, size, aggregation number, zeta potential,
material density, number of oligonucleotide strands per particle,
grafting density, and their relation to hallmark properties of spherical
nucleic acids – biocompatibility, resistance against DNase
I, cellular uptake without the need for transfection agents –
are determined.