title: Premixed, injectable PLA-modified calcium deficient apatite biocement (cd-AB) with washout resistance.
abstract: By using a non-aqueous solution as the mixing liquid, the washout resistance of the calcium deficient apatite biocement (cd-AB) was significantly improved, over that of the conventional method of using cd-AB with water as the liquid phase. In this study, premixed and injectable cd-AB was prepared, which had the advantage of being stable in the syringe and hardens only after being delivered to the defect area. The cd-AB powder with a Ca/P ratio of 1.5 consists of a mixture of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA). A solution of polylactide (PLA) in N-methyl-2-pyrrolidone (NMP) was used as the liquid phase of the premixed cd-AB. The premixed cd-AB paste injected into an aqueous environment exhibited excellent washout resistance. The premixed cd-AB had longer setting time and lower compressive strength than conventional cd-AB. The hydration products of premixed cd-AB were a mixture of calcium deficient hydroxyapatite (cd-HA) and PLA. In vitro Tris-HCl immersion tests demonstrated that the premixed cd-AB could be degradable. The results revealed that the premixed cd-AB was cytocompatible and had no adverse effects on the attachment and proliferation of MG-63 osteoblast-like cells in vitro. The most distinct advantages of premixed and injectable PLA-modified cd-AB were its excellent washout resistance and in vitro degradability, suggesting that it may be a promising candidate for bone repair.
authors.affiliation: School of Chemical Engineering, The University of Adelaide, SA, Australia. fan.wu@adelaide.edu.au
authors.forename: Fan
authors.initials: F
authors.lastname: Wu
authors.forename: Yung
authors.initials: Y
authors.lastname: Ngothai
authors.forename: Jie
authors.initials: J
authors.lastname: Wei
authors.forename: Changsheng
authors.initials: C
authors.lastname: Liu
authors.forename: Brian
authors.initials: B
authors.lastname: O'Neill
authors.forename: Yuequn
authors.initials: Y
authors.lastname: Wu
mesh_terms: D001031:Apatites / Q000737:chemistry*; D001843:Bone Cements / Q000494:pharmacology*; D002118:Calcium / Q000737:chemistry*; D002460:Cell Line; D019245:Compressive Strength / Q000187:drug effects; D006244:Hardness / Q000187:drug effects; D006801:Humans; D007267:Injections; D008422:Materials Testing / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D011091:Polyesters / Q000737:chemistry*; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D001843:Bone Cements; D011091:Polyesters; C033616:poly(lactide); D002118:Calcium