Particles

1. An embolic composition including:

particles including a reaction product of a prepolymer solution including:

a polyether macromer; and

a monomer including a single ethylenic unsaturation,

wherein the embolic; composition is configured to fit through an inner diameter of a microcatheter.

2. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.0155 inch.

3. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.0160 inch.

4. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.0165 inch.

5. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.0170 inch.

6. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.0175 inch.

7. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.018 inch.

8. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.019 inch.

9. The embolic composition of claim 1 , wherein the inner diameter is at most about 0.02 inch.

10. The embolic composition of claim 1 , wherein the polyether macromer is a poly(ethylene glycol) diacrylamide macromer, a poly(ethylene glycol) diacrylate macromer, a poly(ethylene glycol) dimethacrylate macromer, a poly(ethylene glycol) dimethacrylamide macromer, or a combination thereof.

11. The embolic composition of claim 1 , further comprising a visualization agent.

12. The embolic composition of claim 11 , wherein the visualization agent is particles of radiopaque materials or halogen containing monomers.

13. The embolic composition of claim 12 , wherein the halogen containing monomer is an iodine containing monomer.

14. The embolic composition of claim 13 , wherein the iodine containing monomer has a structure:

15. The embolic composition of claim 12 , wherein the particles of radiopaque materials include barium, bismuth, tantalum, platinum, and gold.

16. The embolic composition of claim 12 , wherein the particles of radiopaque materials include barium sulfate.

17. The embolic composition of claim 1 , wherein the prepolymer solution further includes a crosslinker having a structure

wherein each n is independently 1-20;

wherein d, e, and f are each independently 1-20;

or a combination thereof.

18. The embolic composition of claim 1 , wherein the embolic particles are substantially spherical.

19. The embolic composition of claim 1 , wherein the embolic particles are substantially stable.

20. The embolic composition of claim 1 , wherein the embolic particles are substantially biodegradable.