title: Preparation of hollow hydroxyapatite microspheres.
abstract: The preparation of hollow hydroxyapatite (HA) microspheres as potential drug-delivery vehicles was investigated. A lithium-calcium-borate (10Li(2)O-15CaO-75B(2)O(3)) (mol%) glass, made by fusing the components at 1100 degrees C for 1 h, was ground to a powder and passed through a flame at approximately 1400 degrees Celsius to spheroidize the particles. The resulting glass microspheres (106-125 microm in diameter) were reacted in 0.25 M K(2)HPO(4) solution for 5 days at 37 degrees Celsius and pH 10-12, resulting in the formation of porous, hollow microspheres of a calcium phosphate (Ca-P) material with external diameters similar to those of the original glass particles. Heat treatment at 600 degrees Celsius for 4 h partially converted the Ca-P material to HA, as confirmed by X-ray diffraction, and also increased the strength of the hollow microspheres.
authors.affiliation: Institute of Bioengineering & Information Technology Materials, Tongji University, Shanghai, 200092, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Wenhai
authors.initials: W
authors.lastname: Huang
authors.forename: Deping
authors.initials: D
authors.lastname: Wang
authors.forename: Brian W
authors.initials: BW
authors.lastname: Darvell
authors.forename: Delbert E
authors.initials: DE
authors.lastname: Day
authors.forename: Mohamed N
authors.initials: MN
authors.lastname: Rahaman
mesh_terms: D001881:Borates / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D016503:Drug Delivery Systems; D017886:Durapatite / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008094:Lithium / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry; D016062:Porosity; D017680:Potassium Compounds / Q000737:chemistry; D011208:Powders / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D001881:Borates; D002130:Calcium Phosphates; D010710:Phosphates; D017680:Potassium Compounds; D011208:Powders; D012996:Solutions; D017886:Durapatite; D008094:Lithium; C013216:potassium phosphate; D002118:Calcium