Production of hydroxyapatite(HA) nanoparticle and HA/PCL tissue engineering scaffolds for bone tissue engineering

Hydroxyapatite (HA) is biological apatite has close similarity of composition with human bone and teeth. Thus, it has been used in biomedical application in orthopedic and dentistry. The wet slurry of HA was successfully produced by mixing an acetone solution of calcium nitrate 4-hydrate with an aqueous solution of ammonium phosphate and ammonium carbonate with control pH of 11. The nano-emulsion was kept in freezer about one day and after that was kept in freeze drying machine about three days to obtain dry HA powder with low degree of agglomeration. The nanoparticles were studied under scanning electron microscopy (SEM). Energy Dispersive Xray (EDX) showed the spectrum of elements in HA with Ca/P ratio close to biological bone. The polycaprolactone (PCL) and hydroxyapatite/polycaprolactone (HA/PCL) composite scaffolds were produced using thermally induced phase separation (TIPS) technique. The scaffolds were studied under SEM and it was observed that both types of scaffolds had porous structures. The pore sizes of HA/PCL scaffold was slightly decreased compared to PCL scaffold. The HA nanoparticles were successfully produced and the PCL and HA/PCL scaffolds showed promises for bone tissue engineering application.