ساخت و بهينه سازي نانوذرات منيزيم فلوئورهيدروكسي آپاتيت و داربست نانو كامپوزيتي پلي كاپرولاكتون-نانو ذرات با كاربرد باز خلق بافت استخواني

چكيده انگليسي :

Preparation and optimization of magnesium flouradated hydroxyapatite nanoparticles andpoly caprolactone nanocomposite scaffold nanoparticles for bone tissue engineering Zeinab Fereshteh z fereshteh@ma iut ac ir Date of Submission August 25 2014 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran1st supervisor Mohammadhossein Fathi Professor fathi@cc iut ac ir2nd supervisor Reza Mozaffarinia Associate Professor Mozaffarinia@yahoo comDepartment Graduate Program Coordinator Dr Keyvan RaeissiAbstractThe aim of this study was to prepare and characterize the poly caprolactone Mg doped fluorapatitenanoparticles PCL nMg FA nanocomposite electrospun scaffolds The first step Of this work Thenanostructured fluorapatite FA Ca 10 PO4 6 OH 2 xFx was synthesized with the starting materials ofCaCO3 P2O5 and CaF2 via a mechanochemical process The effects of milling time and fluorine ionconcentration were investigated The products characterized by X ray diffraction XRD scanningelectron microscopy SEM transmission electron microscopy TEM and Fourier transform infraredspectroscopy FTIR analysis The FA nanoparticles with an average diameter of about 15 30 nm weresuccessfully prepared after 10 h milling time The results show incorporation of F ions into the apatiteresulted in the decrease of the lattice parameters about 1 15 The effect of solvent type on distributionof nanoparticles and mechanical properties of the scaffolds was also investigated in order to obtain anoptimized composition The optimized conditions were obtained by changing the electrospinningparameters such as Polymer concentration applied voltage and nozzle to collector distance Electrospunnanofibers prepared by ethanol chloroform system are more uniform 0 692 0 0783 m and severaltimes smaller than those obtained by other systems Addition of Mg FA nanoparticles decreased theaverage fiber diameters from 0 490 0 073 m pure PCL scaffold to 0 322 0 199 m PCL 20 wt nMg FA scaffold Optimized nanofibrous scaffold was obtained by 5 wt nMg FA while its tensilestrength and elastic modules were significantly enhanced compered to PCL scaffolds The scaffolds werecharacterized with regard to structural and mechanical properties degradation bioactivity and cellularinteractive responses However due to the high surface energy of such NPs they cannot be well dispersedin a biopolymer matrix to prepare a polymer ceramic composite which is usually demanded for tissueengineering applications To overcome this shortcoming the surface of nMg FA was modified using afew well known natural amino acids as the cost effective and environment friendly biomaterials in thepresent research The L leucine L isoleucine L alanine and L phenylalanine amino acids were employedas the coupling agents and the surface modification of nMg FA was carried out by means of sonicationtechnique The results confirmed that using amino acid molecules leads to the uniform dispersion of nMg FA in the organic environment by making the surface of NPs hydrophobic although the length andchemical reactivity of amino acid molecules affect the efficiency of NPs dispersion The uniformdistribution of nMg FA is a desired condition for polymer ceramic composite preparation which is highlyapplicable for biomedical purposes At that point Mg doped fluorapatite nanoparticles was surfacemodified using amino acids as modifier and PCL surface modified Mg doped fluorapatite nanoparticlesscaffolds were developed This scaffold was also characterized with regard to structural and mechanicalproperties degradation bioactivity and cellular interactive responses Keywords Mechanochemical process Electrospining Mg doped fluorapatite nanoparticles Nanocomposite Surface modification 1 IntroductionSeveral inorganic biomaterials such as bioactive ceramics including silicate glasses 1 forstrite 2 tricalcium phosphate hydroxyapatite HA and selected compositions of apatite have been widely usedfor bone regeneration applications T

فرشته، زينب

ساخت و بهينه سازي نانوذرات منيزيم فلوئورهيدروكسي آپاتيت و داربست نانو كامپوزيتي پلي كاپرولاكتون-نانو ذرات با كاربرد باز خلق بافت استخواني

فرايند فعال سازي مكانيكي , الكتروريسي , اصلاح سازي سطح