title: Influence of a cellulosic ether carrier on the structure of biphasic calcium phosphate ceramic particles in an injectable composite material.
abstract: An injectable composite material based on biphasic calcium phosphate (BCP) and a nonionic cellulose ether has been elaborated for use in percutaneous surgery for spine fusion. This paper reports the characterization results of this material by spectroscopic techniques including X-ray diffraction (XRD), infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) fitted with an energy dispersive X-Ray analysis system and high-resolution transmission electron microscopy (HR-TEM). From FTIR and XPS results, it was observed that the adhesion between the polymer and the ceramic might be insured by oxygen bridging developed through an ionic bonding between calcium ions and (C-O) groups of the polymer. Moreover, XPS showed attraction of Ca2+ ions in the polymer matrix, while the ceramic surface was modified in a HPO4(2-) -rich layer. These results suggest a possible dissolution/precipitation process at the interface ceramic/polymer. HR-TEM observations supported this hypothesis, showing a light contrasted fringe at the surface of the ceramic grains in the composite paste. As well, changes in the XRD spectra could indicate a small decrease in the crystal size of the BCP powder through the contact to polymer solution. In addition, SEM observation showed a decrease of the initial BCP granulometry. Aggregates of 80-200 microm seemed to be mostly dissociated in micrograins. The ceramic grains were coated with and bonded between each other by the polymer matrix, which acted as spacer in between the ceramic grains, creating a macroporous-like material structure.
authors: Laboratoire de recherche sur les Tissus Calcifíes et les Biomatériaux UPRES EA 2159, Nantes, France.
authors: A
authors: A
authors: Dupraz
authors: T P
authors: TP
authors: Nguyen
authors: M
authors: M
authors: Richard
authors: G
authors: G
authors: Daculsi
authors: N
authors: N
authors: Passuti
mesh_terms: D001672:Biocompatible Materials / Q000008:administration & dosage / Q000737:chemistry*; D002130:Calcium Phosphates / Q000008:administration & dosage / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004337:Drug Carriers; D004338:Drug Combinations; D004577:Electron Probe Microanalysis; D004987:Ethers / Q000737:chemistry; D065347:Hypromellose Derivatives; D007267:Injections; D008747:Methylcellulose / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D013242:Sterilization; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D004337:Drug Carriers; D004338:Drug Combinations; D004987:Ethers; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D065347:Hypromellose Derivatives; C485838:calcium phosphate, monobasic, anhydrous; D008747:Methylcellulose; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous