title: Crystallinity control of apatite through Ca-EDTA complexes and porous composites with PLGA.
abstract: Apatite compounds with different levels of crystallinity were prepared using Ca-EDTA complexes. Ca-deficient hydroxyapatite (CDHA) with low crystallinity was synthesized by ultrasonic stirring of a mixture of Ca-EDTA complex, phosphoric acid, and ammonium hydroxide in hydrogen peroxide aqueous solution. Mixtures of carbonate hydroxyapatite (HA) and CDHA with higher crystallinity were also prepared from a solution involving the same complex. The porous composites with lower or higher crystallinity apatite with a copolymer of poly(L-lactide-co-glycilide)(70/30) (PLGA(70/30)) were fabricated by a solution-casting/particles leaching method. The apatites and porous composites were characterized, and it was found that the degradation of composites of apatite with a low level of crystallinity was fastest in phosphate-bufferd saline (PBS) solution compared with other apatite composites with higher levels of crystallinity; however, the rate was smaller than that of PLGA alone. Plasma treatment influenced the degradation of composites in PBS and apatite precipitation in simulated body fluid (SBF). Hydroxyapatite deposition on the PLGA composite with the low crystallinity occurred six times faster than that on PLGA alone after immersion in SBF. The incorporation of apatite into the PLGA matrix did not cause any adverse effects on cell attachment in an assay employing human gingival fibroblasts. This study suggested that the current apatite and PLGA porous composite will be a promising scaffold material for tissue engineering.
authors.affiliation: Faculty of Engineering, Kogakuin University, Tokyo, Japan. fu01147@ns.kogakuin.ac.jp
authors.forename: Chihiro
authors.initials: C
authors.lastname: Mochizuki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hara
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Sato
authors.forename: Tohru
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.forename: Xixue
authors.initials: X
authors.lastname: Hu
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Shenguo
authors.initials: S
authors.lastname: Wang
mesh_terms: D001031:Apatites / Q000737:chemistry*; D002478:Cells, Cultured; D004492:Edetic Acid / Q000737:chemistry*; D005347:Fibroblasts; D005881:Gingiva / Q000166:cytology; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D004492:Edetic Acid