Method to improve hydroxyapatite implantation and stimulate bone regeneration
View Patent ↗Hydroxyapatite is treated by a combination of nitridation and the application of bone morphogenetic protein or DNA encoding such a protein to improve the tissue compatibility and affinity of the hydroxyapatite, rendering the hydroxyapatite more useful as a material for biomedical implants.
1. A method of increasing the affinity of a hydroxyapatite component of a biomedical implant for native bone or tissue, said method comprising the following steps in any order:
(a) nitriding the surface and a region adjacent to the surface of said hydroxyapatite component to about 1% to about 4% by weight nitridation by contacting said hydroxyapatite with a member selected from the group consisting of ammonia and ionized molecular nitrogen, and
(b) after step (a), treating the surface of said hydroxyapatite component with a protein selected from the group consisting of BMP 2, BMP 3, BMP 4, BMP 5, BMP 6, and BMP 7.
2. A method in accordance with claim 1 in which step (b) comprises adsorbing said protein onto said surface.
3. A method in accordance with claim 1 in which said protein is BMP 4.
4. A method in accordance with claim 1 in which said protein is BMP 6.
5. A method in accordance with claim 1 in which said protein is BMP 7.
6. A biomedical implant having a hydroxyapatite component with a surface configured for contact with native bone or tissue, said biomedical implant produced by a process comprising:
(a) nitriding the surface and a region adjacent to the surface of said hydroxyapatite component to about 1% to about 4% by weight nitridation by contacting said hydroxyapatite with a member selected from the group consisting of ammonia and ionized molecular nitrogen, and
(b) after step (a), treating the surface of said hydroxyapatite component with a protein selected from the group consisting of BMP 2, BMP 3, BMP 4, BMP 5, BMP 6, and BMP 7.
7. A biomedical implant in accordance with claim 6 in which said protein is adsorbed onto said surface.
8. A biomedical implant in accordance with claim 6 in which said protein is BMP 4.
9. A biomedical implant in accordance with claim 6 in which said protein is BMP 6.
10. A biomedical implant in accordance with claim 6 in which said protein is BMP 7.