Surface modified protein microparticles

1. A microparticle, comprising:

a cross-linked protein shell, and

a covalently-attached surface coating.

2. The microparticle of claim 1 , wherein the protein shell contains at least one moiety selected from the group consisting of amine moieties, hydroxyl moieties, carboxylate moieties and sulfhydryl moieties.

3. The microparticle of claim 1 , wherein the surface coating comprises polyethylene glycol.

4. The microparticle of claim 3 , wherein the surface coating further comprises a ligand for a cell-surface receptor.

5. The microparticle of claim 4 , wherein the ligand is folate.

6. The microparticle of claim 3 , wherein the surface coating further comprises a second protein.

7. The microparticle of claim 1 , wherein the surface coating comprises a second protein.

8. The microparticle of claim 6 , wherein the second protein is an antibody.

9. The microparticle of claim 7 , wherein the second protein is an antibody.

10. The microparticle of claim 1 , wherein the cross-linked protein shell comprises cross-linked albumin.

11. The microparticle of claim 3 , wherein the cross-linked protein shell comprises cross-linked albumin.

12. A microparticle, comprising a cross-linked protein shell, and a surface coating comprising particles.

13. The microparticle of claim 12 , wherein the cross-linked protein shell comprises cross-linked albumin.

14. The microparticle of claim 12 , wherein the particles are colloidal particles selected from the group consisting of ceramics, metals and semiconductors.

15. The microparticle of claim 12 , wherein the particles are selected from the group consisting of melanin, carbon, gold, and silica.

16. The microparticle of claim 1 , further comprising a core comprising a pharmaceutically active compound.

17. The microparticle of claim 1 , further comprising a core comprising a member selected from the group consisting of Gd complexes, melanin, colloidal gold, iron oxide, titanium dioxide, and fluorocarbons.

18. The microparticle of claim 12 , further comprising a core comprising a pharmaceutically active compound.

19. The microparticle of claim 12 , further comprising a core comprising a member selected from the group consisting of Gd complexes, melanin, colloidal gold, iron oxide, titanium dioxide, and fluorcarbons.

20. The microparticle of claim 1 , further comprising a core comprising a liquid crystalline material.

21. The microparticle of claim 12 , further comprising a core comprising a liquid crystalline material.

22. The microparticle of claim 1 , wherein the cross-linked protein shell comprises at least one cross-linked protein, the protein selected from the group consisting of hemoglobin, pepsin, immunoglobulin, lipase, peroxidase and myoglobin.

23. The microparticle of claim 12 , wherein the cross-linked protein shell comprises at least one cross-linked protein, the protein selected from the group consisting of hemoglobin, pepsin, immunoglobulin, lipase, peroxidase and myoglobin.

24. The microparticle of claim 12 , wherein the cross-linked protein shell encapsulates a core.

25. A microparticle, comprising:

a core, and a shell encapsulating the core, and

a surface coating on the shell,

wherein the shell comprises proteins that are cross-linked together, and

the surface coating comprises particles.

26. The microparticle of claim 25 , wherein the proteins comprises at least one member selected from the group consisting of albumin, hemoglobin, pepsin, immunoglobin, lipase, peroxidase, and myoglobin.

27. The microparticle of claim 25 , further comprising at least one moiety selected from the group consisting of amine moieties, hydroxyl moieties, carboxylate moieties and sulfhydryl moieties.

28. The microparticle of claim 25 , wherein the proteins comprise a chemical modification.

29. The microparticle of claim 28 , wherein the chemical modification comprises a carbodiimide.