Production of copper-containing calcium phosphate and its evaluation of deodorizing and antibacterial properties
- What is calcium phosphate?
- Deodorant properties of calcium phosphate
- Copper-containing hydroxyapatite(Cu-HA)
- Addition to calcium phosphate
- Purpose of research
- Slides
Calcium phosphate is a solid containing phosphate ions[PO4-] and calcium ions[Ca2+], and is abundant in nature as a component of apatite and the bones of living organisms. The most famous one is hydroxyapatite. Hydroxyapatite is a substance that accounts for 60% of human bones and 97% of tooth enamel, and is the most familiar calcium phosphate.
The type of calcium phosphate is determined by the ratio of Ca and P in the crystal (Fig.1). Since calcium phosphate has different characteristics depending on the type, its application fields are diverse (Fig.2).
Fig.1. Types of calcium phosphate and the ratio of Ca and P
Fig.2. Applications of calcium phosphate[1]
Previous studies have confirmed that hydroxyapatite (HA) and β-TCP, which are types of calcium phosphate, have deodorant effects, and it is clear that the deodorant gas selectivity depends on the type of calcium phosphate. (Table1)
Table1. Deodorizing gas selectivity of hydroxyapatite and β-TCP[%][2]
Antibacterial effect and deodorant effect by heavy metal
Heavy metal ions are known to have antibacterial effects. It is said that ionized heavy metals are taken up by bacteria to exert antibacterial properties, but the antibacterial mechanism has not been elucidated. Several theories have been proposed, such as inhibition of protein production by heavy metal ions and oxidation by active oxygen.
There are various types of heavy metals that exhibit antibacterial properties (Fig.4). Many of these metals are expensive precious metals and are known to have adverse effects on the human body, and safe antibacterial metals are limited to Ag and Cu.
It is possible to use heavy metals as a deodorant by using the antibacterial effect of heavy metals to kill odor-causing bacteria.
Fig.3. Antibacterial properties of heavy metal ions[3]
Due to the ion exchange properties of calcium phosphate, it is possible to incorporate metal ions into the crystals of calcium phosphate. As a result, it is possible to combine the deodorant effect of calcium phosphate with the deodorant effect of antibacterial properties, and it is possible to create a more effective deodorant. Cu salt was dissolved in Ca(OH)2 suspension or H3PO4 aqueous solution. There is a solution method that reacts Ca ions, P ions, and Cu ions in a solution by mixing.
We will establish a method for producing Cu-containing calcium phosphate, evaluate its antibacterial properties and cytotoxicity, and verify the safe and antibacterial amount of Cu. This research aims to apply it to safe deodorizing products and environmental cleaning agents that show high effectiveness.
[1](Left)Tsuno group Ltd. HP
https://www.tsuno.co.jp/products/fertilizer-feed/dibasic-calcium-phosphate/"
[1](Center)Olympus Biomaterial Ltd. HP
https://www.biomaterial.co.jp/jp/news/2006/nr002.html
[1](Right)Dr.apatite Ltd. HPよ
https://drapatite.com/?yclid=YSS.EAIaIQobChMImNKJjq7T_wIVAbKWCh0XLAV2EAAYASAAEgJcI_D_BwE
[2]Kazuhide, O.: KAKEN Database, "Deodorant function of hydroxyapatite thin film using sputtering technology" (2004)
[3]Yoshinobu, M.: Antibacterial properties of silver and copper ions Chemistry and education 53(5) (2005)より