title: Controlled size and morphology of EDTMP-doped hydroxyapatite nanoparticles as model for 153Samarium-EDTMP doping.
abstract: Hydroxyapatite (HA) nanoparticles have been studied as nano-sized carriers for the delivery of therapeutic agents. One important consideration for these carriers to be used effectively is their bio-distribution in vivo, of which particle size has a significant effect. In this work, HA nanoparticles doped with Ethylene-diamine-tetramethylene-phosphonate (EDTMP) were synthesized via co-precipitation as a model for HA doped with (153)Samarium ((153)Sm) EDTMP. EDTMP has high affinity for radioactive (153)Sm isotopes that can emit both gamma and beta radiation. The effects of synthesis temperature, amount of dopant and hydrothermal treatment on the size of HA-EDTMP nanoparticles were therefore studied. The results showed that the EDTMP ligand was successfully incorporated in the nanoparticles without changing the crystal structure as shown from X-ray diffractometer (XRD) analysis. From the Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) micrographs, it was observed that shorter rod-like nanoparticles, obtained at low synthesis temperatures, became elongated needle-like nanoparticles with increasing temperature. Increasing dopant amount by five fold increases particle size slightly, while a two fold increase in dopant amount has no significant effect. Hydrothermal treatment increases particle crystallinity and results in smooth elongated rod-like structures. The size of HA nanoparticles doped with EDTMP can therefore be manipulated by controlling synthesis temperature and through hydrothermal treatment.
authors: School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore.
authors: Yuling Jamie
authors: YJ
authors: Han
authors: Say Chye Joachim
authors: SC
authors: Loo
authors: Ngoc Thao
authors: NT
authors: Phung
authors: Hooi Tin
authors: HT
authors: Ong
authors: Stephen J
authors: SJ
authors: Russell
authors: Kah-Whye
authors: KW
authors: Peng
authors: Freddy
authors: F
authors: Boey
authors: Jan
authors: J
authors: Ma
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000737:chemistry; D001610:Beta Particles; D017886:Durapatite / Q000737:chemistry*; D005720:Gamma Rays; D008024:Ligands; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D009942:Organometallic Compounds / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D011868:Radioisotopes / Q000737:chemistry*; D012493:Samarium / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D018712:Analgesics, Non-Narcotic; D008024:Ligands; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D011868:Radioisotopes; D012493:Samarium; C061972:samarium Sm-153 lexidronam; D017886:Durapatite