Therapeutic and imaging compositions and uses thereof

1. A polyrotaxane comprising a poloxamer core and at least one cyclodextrin comprising a nuclide chelating moiety, wherein the polyrotaxane has the general formula:

or a salt thereof,

wherein:

n is an integer from 1 to 30;

C and C′ are the same or different and represent endcapping groups of the formula:

wherein:

L 1 is a (C 1 -C 6 )hydrocarbylene group,

G 1 and G 2 , together, form a radical having the formula:

wherein each L 2 is independently a bond or acyl; each G 3 is a substituted or unsubstituted (C 6 -C 50 )hydrocarbyl group, interrupted by 0 to 5 groups chosen from —O—, —NH—, and —S—, wherein the (C 6 -C 50 )hydrocarbyl group; and each s is independently an integer from 1 to 5; and

t is an integer from 2 to 5;

B is a polyalkylene oxide polymer; and

A is a cyclodextrin.

2. The polyrotaxane of claim 1 , wherein the nuclide chelating moiety is a radical of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA).

3. The polyrotaxane of claim 1 , further comprising at least one of a radionuclide and a paramagnetic nuclide chelated by the nuclide chelating moiety.

4. The polyrotaxane of claim 3 , wherein the paramagnetic nuclide comprises Gd 3+ .

5. The polyrotaxane of claim 1 , wherein G 3 is a substituted or unsubstituted —O—(C 6 -C 50 )alkyl group or a substituted or unsubstituted (C 6 -C 12 )aryl group, wherein the (C 6 -C 50 )alkyl group and the (C 6 -C 12 )aryl group.

6. The polyrotaxane of claim 1 , wherein G 3 is a cholesteryl group or a 2,4,6-trinitro phenyl group.

7. The polyrotaxane of claim 1 , wherein n is an integer from 5 to 15.

8. The polyrotaxane of claim 1 , wherein n is an integer from 3 to 11.

9. The polyrotaxane of claim 1 , having the structure:

wherein:

10. A pharmaceutical composition comprising the polyrotaxane of claim 1 and a pharmaceutically acceptable carrier.