ساخت، مشخصه يابي و ارزيابي خواص مكانيكي و زيست سازگاري نانو كامپوزيت هيدروكسي آپاتيت

چكيده انگليسي :

Synthesis characterization and evaluation of mechanical properties and biocompatibility of hydroxyapatite diopside nanocomposite Samira Ramezani samiramezanii@gmail com Department of Materials Engineering Isfahan University of Technology 84156 83111 Isfahan Iran Degree M Sc Language Farsi Supervisor Dr Rahmatollah Emadi Assoc Prof E mail remadi@cc iut ac ir Abstract A significant challenge in bone tissue engineering is the development of 3D structures serving as ascaffold to fill the bone defects support bone forming cells and promote bone regeneration Due tothe similarity in the chemical composition with bone apatite components hydroxyapatite HA scaffolds have been widely applied as bone substitute However low mechanical properties anddegradation rate of HA have led to development of novel bioceramics and composites with improvedproperties compared to pure HA Results confirmed that the mechanical Physical and biologicalproperties of HA porous scaffolds could be modified using the addition of suitable secondarycomponents CaO SiO2 MgO bioceramics demonstrated high bioactivity and good mechanicalproperties Diopside is a Ca Si and Mg containing bioceramics Results showed that Ca Si Mgcontaining bioceramics not only possessed an improved mechanical strength when compared to HAand ceramics but also were degradable The aim of this study is to develop three dimensional HA diopside porous scaffolds using space holder technique HA and diopside nanopowders weresynthesized via sol gel and combustion sol gel respectively and then various ratios of HA anddiopside nanoparticles 5 10 and 15 wt diopside were mechanically combined Then afteraddition of poly vinyl alcohol PVA and sodium chloride as space holder they compacted usingcompression In order to sinter the compacted powders remove sodium chloride and PVA powdersand develop porous structure samples were heat treated at 1350 c for 2h X ray diffraction XRD technique was utilized to confirm presence of the desired phases in the structure and also todetermine the crystallite of the prepared scaffolds The crystallite sizes were calculated by Scherrerand modified Scherrer equation and the results were compared To evaluate the shape and size of theparticles and crystallites a transmission electron microscopy TEM was applied and the size of HAand diopside nanopowder particles was calculated Scanning electron microscopy SEM was appliedin order to study morphology and surface of nanopowders and scaffolds before and after soaking insimulated body fluid SBF Energy dispersive X ray spectroscopy EDS was utilized to evaluate thechemical composition and distribution of elements in scaffolds Furthermore axial compression testwas applied to study the mechanical properties of scaffolds Bioactivity of different scaffolds wasinvestigated by soaking them in SBF for various periods 14 and 28 days The concentration ofcalcium and phosphorus ions in SBF and the content of pH of SBF were determined for variousperiods by ICP OES method and pH meter respectively Results showed that composite scaffoldswith pore sizes in the range of 200 340 m appearance porosity of 76 82 and compressivestrength of 1 2 3 2 MPa were developed SEM images of scaffolds after soaking in SBF depictedthe tiny agglomerated bone like apatite particles Also biocompatibility evaluations by MTT methodshowed that scaffolds could stimulate cell proliferation of Osteoblast like cells and they did not haveany cytotoxicity as compared to control sample Considering the results obtained it seems that manufactured scaffolds could be a good candidate for bone tissue engineering Keywords Porous materials Hydroxyapatite Diopside Mechanical properties Biocompatibility

رمضاني، سميرا

ساخت، مشخصه يابي و ارزيابي خواص مكانيكي و زيست سازگاري نانو كامپوزيت هيدروكسي آپاتيت - ديوپسيد

داربست سه بعدي , عامل فضاساز