Synthesis of spherical nucleic acids using lipophilic moieties
Spherical nucleic acids (SNA) carrying self-aggregating oligonucleotides are described herein. Compositions of the SNA include discrete nanostructures that are not aggregated. Related methods are also described.
1. A nanostructure comprising:
a spherical nucleic acid (SNA) comprising a core, a lipid shell having an inner surface surrounding the core and an outer surface, and an oligonucleotide linked to a lipophilic moiety wherein the oligonucleotide is functionalized to the lipid shell through interaction between the lipid shell and at least a portion of the lipophilic moiety and the oligonucleotide is oriented radially outwards, wherein the lipophilic moiety is comprised of two or more lipophilic groups and has the following structure:
-L1-(Spacer) n -L2-(Spacer) n1 -L3-X-(alkyl group) m ,
wherein L1, L2, and L3 are each linkers and independent of one another are a phosphodiester or phosphorothioate bond or short chain linkage, wherein the spacer is an oligoethylene glycol spacer, wherein n and n1 are independently 0-3, wherein at least one of n and n1 is not 0, wherein X is a doubler or trebler, the alkyl group is a C 6 -C 30 saturated or unsaturated alkyl group and m is 2-3, wherein the doubler and trebler have the following structures, respectively:
2. The nanostructure of claim 1 , wherein the oligoethylene glycol spacer is a HEG spacer (hexaethylene glycol).
3. The nanostructure of claim 1 , wherein L1, L2, and L3 are phosphodiester linkages.
4. The nanostructure of claim 1 , wherein the lipid shell comprises 1,2-dioleoyl-sn-glycero-3-phophocholine (DOPC).
5. The nanostructure of claim 1 , wherein the oligonucleotide is a single stranded oligonucleotide and/or an immunostimulatory oligonucleotide.
6. The nanostructure of claim 1 , wherein the oligonucleotide is a self-aggregating oligonucleotide containing a self-complementary motif.
7. A composition of the nanostructures of claim 1 .
8. The nanostructure of claim 1 , wherein the oligonucleotide contains a G-rich motif.
9. The nanostructure of claim 1 , wherein the oligonucleotide is an immunostimulatory oligonucleotide and/or an antisense oligonucleotide.
10. The nanostructure of claim 9 , wherein the immunostimulatory oligonucleotide stimulates a toll-like receptor 9 (TLR9).
11. The nanostructure of claim 1 , wherein the core is a hollow core or a solid core.
12. The composition of claim 7 , wherein the composition has a polydispersity index (PDI) of 0.1-0.4.
13. The composition of claim 7 , wherein the nanostructures have a Z average diameter of 30-1,300 nm.