DELIVERY OF HYDROPHOBIC ACTIVE AGENT PARTICLES

1 - 20 . (canceled)

21 . A drug delivery device comprising:

a substrate;

a hydrophilic polymer layer disposed on the substrate;

a layer of coated therapeutic agent particles disposed on the hydrophilic polymer layer, the coated therapeutic agent particles comprising:

a particulate hydrophobic therapeutic agent core; and

a cationic agent at least partially surrounding the particulate hydrophobic therapeutic agent core, the cationic agent comprising a lipid or a polymer and exhibiting affinity for the surface of a cell membrane.

22 . The drug delivery device of claim 21 , wherein the hydrophilic polymer layer includes a polymer with pendent photoreactive groups that are capable of being crosslinked.

23 . The drug delivery device of claim 21 , wherein the cationic agent is selected from the group consisting of polyethylenimine (PEI) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP).

24 . The drug delivery device of claim 21 , further comprising a nucleic acid associated with the cationic agent.

25 . The drug delivery device of claim 24 , wherein the nucleic acid includes siRNA.

26 . The drug delivery device of claim 21 , wherein the particulate hydrophobic therapeutic agent comprises paclitaxel.

27 . The drug delivery device of claim 21 , wherein the cationic agent is electrostatically attracted to negative charges associated with a lipid bilayer of a cell membrane.

28 . The drug delivery device of claim 21 , further comprising an additive matrix in which the coated therapeutic agent particles are disposed.

29 . The drug delivery device of claim 28 , wherein the additive matrix is hydrophilic and comprises a polymer selected from the group consisting of polyethylene glycol (PEG), polyvinyl alcohol (PVA), and polyvinylpyrrolidone (PVP).

30 . A method of forming a drug delivery coating, the method comprising:

applying a hydrophilic base coat onto a substrate;

forming coated therapeutic agent particles, the coated therapeutic agent particles comprising a particulate hydrophobic therapeutic agent and a cationic agent disposed over the particulate hydrophobic therapeutic agent core;

applying the coated therapeutic agent particles to the substrate.

31 . The method of claim 30 , wherein forming the coated therapeutic agent particles includes using a cationic polymer to surround the particulate hydrophobic therapeutic agent core.

32 . The method of claim 30 , wherein the hydrophilic base coat includes a photo-crosslinker with at least two aryl ketone functionalities.

33 . The method of claim 30 , additionally comprising the step of applying actinic radiation to covalently bond the hydrophilic base coat to the substrate.

34 . The method of claim 30 , further comprising the step of associating a nucleic acid with the cationic agent during the formation of coated therapeutic agent particles.

35 . The method of claim 34 , wherein the nucleic acid comprises siRNA.

36 . The method of claim 30 , wherein the particulate hydrophobic therapeutic agent is selected from the group consisting of paclitaxel, sirolimus, and rapamycin.

37 . The method of claim 30 , further comprising the step of adding an additive to form a matrix with the coated therapeutic agent particles.

38 . The method of claim 37 , wherein the additive comprises a polysaccharide.

39 . The method of claim 37 , wherein the additive is selected from the group consisting of glycogen, dextran, and gelatin.

40 . A drug delivery system comprising:

a hydrophilic outer surface formed on a substrate;

a matrix contacting the hydrophilic outer surface, the matrix comprising:

particulate hydrophobic therapeutic agent particles; and

a cationic agent, the cationic agent comprising a lipid or a polymer;

wherein the matrix is configured to release the therapeutic agents upon contact with aqueous biological environments.