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Chitosan/Gelatin/Mg Substituted Hydroxyapatite Nano Composite Scaffold for Bone Tissue Engineering

Azamian, Fariba | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: English
  3. Document No: 47646 (56)
  4. University: Sharif University of Technology, International Campus, Kish Island
  5. Department: Science and Engineering
  6. Advisor(s): Mohammadi, Mohammad Reza; Fathi, Mohammad Hossein
  7. Abstract:
  8. The present study is work on fabrication and characterization of a chitosan/ gelatin/ Mg substituted hydroxyapatite nano composite scaffold for bone tissue engineering. At the first step pure and Mg-substituted hydroxyapatite (HA) (Ca10-xMgx(PO4) 6OH2) nano-hexagonal rods with 14–45 nmdiameter.for this, calcium nitrate, magnesium phosphate hydrate and potassium dihydrogenphosphate were used as precursors for Ca, Mg, and P, respectively. Calculated amounts of magnesium ions (Mg+2) especially from 0 to 8% (molar ratio) were incorporated as substituted into the calcium sol solution. Deionized water was used as a diluting media for HA sol preparation and ammonia was used to adjust the pH= 9. After aging, the HA gel was dried at 60 ℃ and calcined at 450 ℃for 1h. The calcined powders were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). The results of XRD and FTIR values ranged between 0.45 and 2.11 mg/lindicated that the magnesium added in the calcium solution was incorporated in the lattice structure of HA so prepared, while those obtained by SEM confirmed the influence of Mg on their morphology.At the second step, Mg substituted HA/ chitosan/ gelatin scaffold were prepared by freeze-drying method. The fabricated composite scaffolds werecharacterized using SEM, XRD and FT-IR studies. The composite scaffolds were highly porous with a pore size of 7-80 μm. Also compared with pure chitosan/gelatin, the composite with nano-hydroxyapatite and MgnHA could form apatite more readily during the biomimetic process, which suggests thatthe composite possessed bettermineralization activity. The results indicated that the addition of Mg nano-Hydroxyapatite improved the bioactivity of chitosan/gelatin/Mg nano-hydroxyapatite composite scaffolds.In addition, density, swellingratio, degradation, biomineralization of the composite scaffoldswere studied. The scaffolds showed good swelling character, which could be modulated by varying consentration of Mg in HA. Composite scaffolds in the presence of nHA and MgnHA showed a decreased degradation rateand increased mineralization in SBF
  9. Keywords:
  10. Scaffold ; Hydroxyapatite ; Chitosan ; Gelatin ; Bone Tissue Engineering ; Sol-Gel Method

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