Compositions and methods for transport of molecules with enhanced release properties across biological barriers
Conjugates of a cargo molecule with a transporter molecule are disclosed, where the cargo molecule and the transporter molecule are linked covalently by a releasable linker. The cargo of the conjugate can be a biologically active agent or a reporter molecule. The transporter modulates the transport of the cargo across a biological barrier (e.g., a cell membrane) compared to the transport of the unconjugated cargo. Releasable linkers suitable for rapid and facile conjugation to various types of cargo and transporters are also disclosed, along with methods for using the linkers in the synthesis of conjugates.
1. A composition for transporting a cargo molecule across a biological barrier comprising:
a cargo molecule, wherein the cargo molecule is taxol;
a transporter molecule; and
a releasable linker of the form
which covalently links the cargo molecule and the transporter molecule;
where R 1 is an optionally substituted C 1 -C 8 hydrocarbon group, an optionally substituted group of the form —CH 2 —O—(C═O)—C 1 -C 8 hydrocarbyl, or an optionally substituted C 1 -C 8 hetero chain group;
V is O; and
the composition having the formula (I):
wherein Carg-Nu represents the residue of the cargo molecule “Carg-NuH”, wherein Nu is O;
and Transp-S represents the residue of a transporter molecule “Transp-SH;
and wherein the transporter molecule is a transport polymer comprising from 6 to 25 adjacent arginines.
2. The composition of claim 1 , wherein R 1 is C 1 -C 8 alkyl.
3. The composition of claim 1 , wherein R 1 is —CH 2 CH 2 —.
4. The composition of claim 1 , wherein the composition has the formula:
and any stereoisomer or salt thereof.
5. The composition of claim 1 , wherein the transporter comprises an octaarginine moiety.
6. The composition of claim 5 , wherein the transporter consists of an octaarginine moiety.
7. A method of making a conjugate of a cargo molecule “Carg-NuH”, wherein the cargo molecule is a taxol and Nu is O, and a transport molecule bearing a thiol group of the form “Transp-SH”, and wherein the transporter molecule is a transport polymer comprising from 6 to 25 adjacent arginines, comprising the steps of:
reacting the compound Carg-NuH, the anion Carg-Nu(−), or the salt Carg-Nu(−) M + , where -NuH or -Nu(−) is a nucleophilic moiety and M + is one equivalent of a cation, with a compound of the form Y 1 —W—Y 2 , where Y 1 and Y 2 are leaving groups and can be the same or different, and where W is —(C═O)— to form a compound of the form:
Carg-Nu-W—Y 1 (IIA-gb);
reacting a compound of the form (IIIA-gb)
where
R 1 is an optionally substituted C 1 -C 8 hydrocarbon group, an optionally substituted group of the form —CH 2 —O—(C═O)—C 1 -C 8 hydrocarbyl, or an optionally substituted C 1 -C 8 hetero chain group;
V is O;
br is an integer between 1 and 4 inclusive and indicates the number of “branches” on the R 1 group, and
TLGS is a thiol leaving group stabilizer;
with the transporter molecule to form a compound of form (IVA-gb):
and
reacting the compound (IIA-gb) with the compound (IVA-gb) to form the conjugate of formula (Igb):
8. The method of claim 7 , wherein br is 1.
9. The method of claim 7 , wherein R 1 is C 1 -C 8 alkyl.
10. The method of claim 9 , wherein R 1 is —CH 2 CH 2 —.
11. The method of claim 9 , wherein R 1 is —CH 2 CH 2 CH 2 —.
12. The method of claim 9 , wherein R 1 is —CH 2 CH 2 CH 2 CH 2 —.
13. The method of claim 7 , wherein M + is Li + , Na + , Mg +2 , or Ca +2 .
14. The method of claim 7 , wherein TLGS is selected from the group comprising