Spinulose titanium nanoparticulate surfaces
Vapor plasma deposition of titanium (Ti) metal onto a substrate forms a structured surface that exhibits enhanced cell attachment properties. Initially deposited round nanoparticulate surface structures develop tentacles with a spine or thorn-like appearance upon continued deposition under special conditions. The density and size of the formed spinulose particles can be controlled by timing the deposition intervals. A significant increase in osteoblast, fibroblast and endothelial cell attachment is observed on Ti spinulose surfaces compared to attachment on nanoparticulate surfaces lacking spinulous nanostructure.
1. A method for producing a nanorough spinulose titanium (NST) surface comprising:
depositing titanium by a cyclic nanoplasma deposition process onto a substrate housed within an evacuated chamber;
stopping plasma discharge and gas flow between cycles for between about 5 to about 810 minutes;
restarting plasma discharge and gas flow; and
continuing titanium deposition under initial conditions of deposition for a number of times until a NST surface is formed on said substrate.
2. The method of claim 1 wherein the NST surface is formed on substantially round initially deposited titanium nanoparticles.
3. The method of claim 1 wherein the NST surface comprises pure titanium.
4. The method of claim 1 wherein the depositing is conducted for about 1 min to about 15 min.
5. The method of claim 1 wherein the time between titanium deposition cycles is about 90 min.
6. The method of claim 1 wherein the depositing is continued for about 3 to about 13 cycles.
7. The method of claim 1 wherein the titanium is deposited normal to the substrate surface.
8. The method of claim 1 wherein the titanium is deposited at an angle to the substrate surface.
9. The method of claim 1 wherein the substrate is a metal, metal alloy, polymer or ceramic.
10. The method of claim 9 wherein the substrate is selected from the group consisting of silicone, poly(methylmethacrylate) (PMMA), polyurethane (PU), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyetheretherketone (PEEK), ultra high molecular weight polyethylene (UHMWPE), and polypropylene (PP).
11. The method of claim 1 wherein the substrate is silicon, glass, carbon, salt, titanium, nitinol, CoCrMo or stainless steel.
12. The method of claim 1 wherein the NST surface comprises spinules ranging in average spike height from about 0.22 μm to about 1.12 μm.
13. The method of claim 12 wherein the spinules have an average spike base width between about 0.3 μm and 0.63 μm.
14. The method of claim 13 wherein the NST surface is about 85% covered with spinules.