Studying the Hydrothermal Synthesis of Hydroxyapatite Ca5OH(PO4)3
Poster Number
07
College
College of Arts and Sciences
Department
Chemistry, Physics, Geology, & the Environment
Faculty Mentor
Dr. Maria Gelabert
Abstract
Hydroxyapatite (HA) is a calcium phosphate found naturally in human bone, teeth, and dentin. Studies on its optimization have shown promising results on orthopedic and dental applications involving replacement of bones or teeth. However, this material has not been synthesized with enough strength to fully replace the systems. Additionally, HA poses threats of infection since it is not an exact match to human bone and teeth. After preliminary experiments over a broad pH range, the 6-8 pH range was chosen, with calcium chelating ligand DTPA (diethylenetriaminepentaacetate). Silver was later added to the matrix, due to its natural antibiotic properties, in the form of silver nitrate. HA crystals tend to be acicular, or needle shape, and this is important to for their optical confirmation. Experiments were conducted by adding amounts of calcium nitrate, ammonium hydrogen orthophosphate, potassium hydroxide, DTPA and silver nitrate as applicable, with the aid of OLI Analyzer speciation software, into an autoclave, which was then placed into a convection oven at 200 °C for seven days. Product crystals were washed using water and ethanol, dried and viewed under an optical microscope. Visually, the majority of the identifiable crystals were acicular, and the sizes and habits varied with pH, with larger crystals near biological pH. X-ray powder diffraction data were collected, confirming that hydroxyapatite was synthesized with DTPA as the ligand. Addition of silver, however, produced elemental silver. Studies continue with greatly reduced amounts of silver, to see if phase-pure material may be obtained with silver antibacterial enhancement.
Previously Presented/Performed?
South Carolina EPSCoR Conference, Columbia, South Carolina, January 2016
Grant Support?
Supported by a grant from the South Carolina EPSCoR/IDeA Program
Start Date
22-4-2016 12:00 PM
End Date
22-4-2016 2:00 PM
Studying the Hydrothermal Synthesis of Hydroxyapatite Ca5OH(PO4)3
Rutledge
Hydroxyapatite (HA) is a calcium phosphate found naturally in human bone, teeth, and dentin. Studies on its optimization have shown promising results on orthopedic and dental applications involving replacement of bones or teeth. However, this material has not been synthesized with enough strength to fully replace the systems. Additionally, HA poses threats of infection since it is not an exact match to human bone and teeth. After preliminary experiments over a broad pH range, the 6-8 pH range was chosen, with calcium chelating ligand DTPA (diethylenetriaminepentaacetate). Silver was later added to the matrix, due to its natural antibiotic properties, in the form of silver nitrate. HA crystals tend to be acicular, or needle shape, and this is important to for their optical confirmation. Experiments were conducted by adding amounts of calcium nitrate, ammonium hydrogen orthophosphate, potassium hydroxide, DTPA and silver nitrate as applicable, with the aid of OLI Analyzer speciation software, into an autoclave, which was then placed into a convection oven at 200 °C for seven days. Product crystals were washed using water and ethanol, dried and viewed under an optical microscope. Visually, the majority of the identifiable crystals were acicular, and the sizes and habits varied with pH, with larger crystals near biological pH. X-ray powder diffraction data were collected, confirming that hydroxyapatite was synthesized with DTPA as the ligand. Addition of silver, however, produced elemental silver. Studies continue with greatly reduced amounts of silver, to see if phase-pure material may be obtained with silver antibacterial enhancement.
