Methods of depositing discrete hydroxyapatite regions on medical implants

Abstract

A method for electrochemically depositing discrete regions of calcium phosphate onto a medical implant. The method includes providing an implant including at least one area having a metallic surface. At least a portion of the metallic surface is contacted with an electrolyte solution comprising calcium ions and phosphate ions. The metallic surface is used as a cathode, and an electrical potential is applied between the cathode and the electrolyte solution. The electrical potential is applied with a constant current density of from about 10 to about 50 mA / cm2 for a period of time of from about 1 to about 20 minutes. A plurality of discrete regions of needle-shaped hydroxyapatite crystals are electrochemically deposited onto the metallic surface.

Description

INTRODUCTION[0001]The present technology relates to medical implants having discrete regions of a calcium phosphate (e.g., hydroxyapatite), and methods of their manufacture. In the growing field of medical devices, there is a continued need to provide lightweight orthopedic implants having enhanced in-growth capability. It is known that the time between in-growth of a metallic implant until the full mechanical loadability is achieved can be reduced if the implant has been coated with a calcium phosphate phase (CPP), such as hydroxyapatite.[0002]Hydroxyapatite is a biocompatible material similar in composition to the mineral content of natural bone. As a result, hydroxyapatite coatings on medical orthopedic implants can enhance the implant's osteoconductive potential, among other things. CPP coatings can be deposited onto electroconductive, or metal substrates using solution-based techniques, such as electrochemical deposition or sol-gel deposition. One advantage of using such deposi...

AI Technical Summary

Benefits of technology

[0001]The present technology relates to medical implants having discrete regions of a calcium phosphate (e.g., hydroxyapatite), and methods of their manufacture. In the growing field of medical devices, there is a continued need to provide lightweight orthopedic implants having enhanced in-growth capability. It is known that the time between in-growth of a metallic implant until the full mechanical loadability is achieved can be reduced if the implant has been coated with a calcium phosphate phase (CPP), such as hydroxyapatite.

[0002]Hydroxyapatite is a biocompatible material similar in composition to the mineral content of natural bone. As a result, hydroxyapatite coatings on medical orthopedic implants can enhance the implant's osteoconductive potential, among other things. CPP coatings can be deposited onto electroconductive, or metal substrates using solution-based techniques, such as electrochemical deposition or sol-gel deposition. One advantage of using such deposition processes is that they are not “line of sight” processes and thus can provide a complete coating coverage of complex shaped substrates. With the use of implants having nano-scale texturing, however, such deposition processes can be disadvantageous in that the coating may be applied over the nano-scale texturing, thereby negating its affect. Accordingly, there remains a need to provide methods for using electrochemical deposition techniques to provide discrete regions of CPP, including hydroxyapatite.SUMMARY

Problems solved by technology

With the use of implants having nano-scale texturing, however, such deposition processes can be disadvantageous in that the coating may be applied over the nano-scale texturing, thereby negating its affect.

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