Glyco-decorated spherical
nucleic acids (SNAs) may be attractive
delivery vehicles, emphasizing the sugar-specific effect on the outer
sphere of the construct and at the same time hiding unfavorable distribution
properties of the loaded oligonucleotides. As examples of such nanoparticles,
tripodal sugar constituents of bleomycin were synthesized and conjugated
with a fluorescence-labeled antisense oligonucleotide (AON
ARV7
). Successive copper(I)-catalyzed azide-alkyne and strain-promoted
alkyne-nitrone cycloadditions (SPANC) were utilized for the synthesis.
Then, the glyco-AON
ARV7
conjugates were hybridized with
complementary strands of a C
60
-based molecular spherical
nucleic acid (i.e., a hybridization-mediated carrier). The formation
and stability of these assembled glyco-decorated SNAs were evaluated
by polyacrylamide gel electrophoresis (PAGE), UV melting profile analysis,
and time-resolved fluorescence spectroscopy. Association constants
were extracted from time-resolved fluorescence data. Preliminary cellular
uptake experiments of the glyco-AON
ARV7
conjugates (120
nM solutions) and of the corresponding glyco-decorated SNAs (10 nM
solutions) with human prostate cancer cells (PC3) showed an efficient
uptake in each case. A marked variation in intracellular distribution
was observed.