Coating method
A method of coating a material onto projections provided on a patch. The method includes applying a coating solution containing the material to at least the projections and drying the coating solution to at least the projections using a gas flow.
1. A method of coating a material onto projections provided on a patch, wherein the method includes:
a) applying a coating solution containing the material to at least the projections; and,
b) using a gas flow to i) distribute the applied coating solution over the projections; and ii) dry the coating solution.
2. A method according to claim 1 , wherein the material includes at least one of:
a) nanoparticles;
b) a nucleic acid or protein;
c) an antigen, allergen, or adjuvant;
d) parasites, bacteria, viruses, or virus-like particles;
e) quantum dots, SERS tags, Raman tags or other nanobiosensors;
f) metals or metallic compounds; and,
g) molecules, elements or compounds.
3. A method according to claim 1 , wherein the coating solution includes a therapeutic agent.
4. A method according to claim 3 , wherein the therapeutic agent is at least one of:
a) DNA; and,
b) protein.
5. A method according to claim 1 , wherein the coating solution includes at least one of:
a) a viscosity enhancer;
b) a surfactant; and,
c) an adjuvant.
6. A method according to claim 5 , wherein at least one of:
a) the viscosity enhancer is 0% to 90% of the coating solution; and,
b) the surfactant is 0% to 90% of the coating solution.
7. A method according to claim 5 , wherein the viscosity enhancer is at least one of methylcellulose (MC), carboxymethylcellulose (CMC), gelatin, agar, and agarose.
8. A method according to claim 1 , wherein the coating solution has a viscosity of between 10 −3 Pa·S and 1 Pa·S.
9. A method according to claim 8 , wherein the coating solution has a viscosity of 0.01-0.06 Pa·S.
10. A method according to claim 1 , wherein the coating solution has a surface tension of between 0.023 N/m and 0.073 N/m.
11. A method according to claim 10 , wherein the coating solution has a surface tension of 0.03-0.04 N/m.
12. A method according to claim 1 , wherein the gas flow is induced at least in part by extracting gas from a container containing the patch.
13. A method according to claim 1 , wherein the patch has a surface area of approximately 0.16 cm 2 .
14. A method according to claim 1 , wherein the projections have a length of between 10 to 400 μm.
15. A method according to claim 14 , wherein the projections have a length of 90 μm.
16. A method according to claim 1 , wherein the projections have a radius of curvature of greater than 1 μm.
17. A method according to claim 16 , wherein the projections have a radius of curvature greater than 5 μm.
18. A method according to claim 1 , wherein the projections include a support section and a targeting section.
19. A method according to claim 1 , wherein the projections are solid.
20. A method according to claim 1 , wherein the projections are non-porous and non-hollow.
21. A method according to claim 1 , wherein the patch is at least one of:
a) hydrophobic; and,
b) hydrophilic.
22. A method according to claim 1 , wherein the applied coating solution is evenly distributed over the projections using the gas flow.
23. A method according to claim 1 , wherein using the gas flow to distribute the applied coating solution causes the projections to be completely wetted by the coating solution.
24. A method according to claim 1 , wherein the method includes providing the gas flow using a gas jet directed towards the patch.
25. A method according to claim 24 , wherein the method includes using the gas jet to evenly disperse the coating solution over the projections.
26. A method according to claim 24 , wherein the gas flow is provided at a gas flow rate using the gas jet, the distribution of the applied coating solution over the projections being controlled, at least in part, by selecting the gas flow rate.
27. A method according to claim 24 , wherein the method includes using multiple gas jets to distribute and dry the coating solution.