Mixed micelles

1. A method of delivering an imaging agent to a subject, the method comprising the step administering a mixed micelle comprising the imaging agent to the subject, wherein the mixed micelle comprises (a) a poly(ethylene oxide)-poly[(R)-3-hydroxybutyrate]-poly(ethylene oxide) (PEO-PHB-PEO) molecule synthesized from poly[(R)-3-hydroxybutyrate] diol with a molecular weight of about 2,300 Da and methoxy-poly(ethylene glycol) monocarboxylic acid having a molecular weight of about 4,900 Da and (b) a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) molecule having a molecular weight of about 12,600 wherein each PEO polymer block has about 100 PEO repeat units and the PPO polymer block has about 65 PPO repeat units, wherein the ratio of PEO-PHB-PEO to PEO-PPO-PEO is between about 7.7:3.3 and 6.3:2.7.

2. The method of claim 1 , wherein the imaging agent is a member selected from the group consisting of indocyanine green (ICG), gadolinium or manganese, iron oxide nanoparticles, quantum dots, iodine and barium.

3. The method of claim 2 , wherein the imaging agent is indocyanine green (ICG).

4. The method of claim 1 , wherein the imaging agent is more stable in the subject when administered in the mixed micelle, than when administered in an aqueous solution.

5. The method of claim 1 , wherein the subject has a tumor and the mixed micelle comprising the imaging agent is preferentially taken up by the tumor.

6. The method of claim 1 , further comprising a step of visualizing the imaging agent in the subject.

7. The method of claim 1 , wherein the size of the mixed micelle is between 10-120 nm.

8. The method of claim 1 , wherein the size of the mixed micelle is between 50-120 nm.

9. The method of claim 1 , wherein the size of the mixed micelle is about 110 nm.

10. The method of claim 1 , wherein the mixed micelle is a filamentous micelle.

11. The method of claim 1 , further comprising the step of adding the mixed micelle to a pharmaceutical carrier.