Hydroxyapatite With Controllable Size And Morphology


Invention Summary:

Hydroxyapatite (HAp) is a naturally occurring mineral having the formula Ca10(PO4)6(OH)2; almost 50% of bone is made up of a modified form of this mineral. HAp has attracted much attention for its excellent biocompatibility and bioactivity, and its use as an implant material. Often the material of choice for the fabrication of dense and porous bioceramics, hydroxyapatite’s general uses include biocompatible phase-reinforcement in composites, coatings on metal implants and granular fill for direct incorporation into human tissue. Current methods for HAp synthesis has many drawbacks. Usually a high temperature process is used which lacks the ability to control particle size and morphology, or the process does not produce a phase-pure crystalline product and produces large agglomerates.

An esteemed Rutgers Materials Science professor has developed a technology that meets the need for phase-pure hydroxyapatite having a controllable size and morphology, a method for producing uniform hydroxyapatite films and coatings, and a method for deposition of the coatings with an intermediate bonding layer over a substrate surface. This invention allows a range of particle size to be isolated through specific conditions. Both the ceramic powder and film formation involves the appropriate mixture of reagents heated to a specific time and low temperature with a controlled stirring speed. The products are then isolated in a v ery simple manner.

Market Application:

This technology is ideal for coating surgical implants, but can also be used in applications for bone fillers and cement.

Advantages:

  • Specific particle size and morphologies (Relevant morph-ologies on primary or secondary hierarchy include spheres, hexagons, tubular, platelets, barrels, and cube-shaped structures)
  • Controlled particle sizes from 50 nm to 5 μm with aspect ratios of 0.5 to 5.0
  • Low temperature coating process
  • Uniform film/coating with consistent particle morphology and controlled film thickness
  • Intermediate bonding layer for better substrate adhesion

Intellectual Property & Development Status:

Patents pending: US2008/0206554 "Hydroxyapatite with Controllable Size and Morphology" and PCT/US10/54146.

Relevant Publications:

  • Phase-Sequenced Deposition of Calcium Titanate/ Hydroxyapatite Films with Controllable Crystallographic Texture onto Ti6Al4V by Triethyl Phosphate-Regulated Hydrothermal Crystallization. Crystal Growth and Design, 2009, Vol. 9, No. 8, 3412-3422
  • Crystallographically engineered, hydrothermally crystallized hydroxyapatite films: an in vitro study of bioactivity. Journal of Materials Science - Materials in Medicine, 2010, Vol. 21, No. 5, 1531-1542