Investigation Of Organic/Inorganic Composite Biological Activity Bone Cement As Drug Carrier

The investigation of bone cement will provide a new repairing method for solving thebone damage problem. The AW bioglass has good bioactivity, bone conductivity,biocompatibility and mechanical properties, so it has been used widely for bone′s substitution,restoration and bone damage filling material on clinical. Compared with the traditionalmelting method, the sol-gel method has many advantages, such as, low heat-treatedtemperature and excellent bioactivity. However, currently, the research of using sol-gelderived AW bioglass as the solid powder of bone cement has been rarely reported..In this paper, preparation of AW bioglass by sol-gel method was firstly studied. It wasfound that AW bioglass has already formed Ca₅（PO₄）₃F and CaSiO₃at700℃heat-treatedtemperature; with the increasing of temperature to1150℃, new phase of Ca₂P₂O₇formed andmelting phenomenon appeared. Using the AW bioglass heat-treated at700,900and1100℃asthe GBC′s solid power, the phase composition, microstructure and compressive strength ofthree kinds of GBCs before and after′s immersion in SBF were studied. It was found that thebone cement prepared with bioglass powder heat-treat at900℃had the best properties.Using the AW bioglass heat-treated temperature at900℃as the GBC’s solid powder, theAW bioglass based bone cement was prepared by mixing with different setting liquid. Theinfluence of composition of setting liquid on the mechanical properties and bioactivity ofGBC were investigated. The setting time of the GBC sample was determined by the Gilmoredouble-needle method. The GBC was immersed in simulated body fluid（SBF） solution foranalyzing its bioactivity. The phase composition, microstructure and compressive strengthwere analyzed using X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）,scanning electronic microscope（SEM） and omnipotence electronic intensity measuringinstrument. The results indicated that a certain amount of HA crystals formed in the GBC withcitric acid/K2HPO4/KH2PO4complex setting liquid after setting reaction, and the quantity ofHA crystals increased and a few CaCO₃crystals formed, and the GBC presented porousconfiguration, and with prolonging of immersion time in SBF, the variance of compressivestrength is slight.With HA-GEL composite powders as the additive of the AW bioglass bone cement, thebreaking strength of the GBC was increased, and a certain amount of HA crystals formed aftersetting reaction, and with prolonging of immersion time in SBF it had newly formed CaCO₃,and the formation of HA crystal was complete relatively. The drug release mode of organic/inorganic composite bone cement as drug carrier was investigated by UV-VIS. Theinfluence of the different drug content on drug releasing was compared. The results indicatedthat the GBC with drug loading can make drug release slowly, especially the GBC with6wt%drug content had better drug slow release function relatively.