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Sol-Gel Preparation and Study of Bio-Composite Scaffold Containing Chitosan-Gelatin/ Nano-Hydroxyapatite for Bone Tissue Engineering

Amini, Nooshin | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: English
  3. Document No: 47451 (56)
  4. University: Sharif University of Technology, International Campus, Kish Island
  5. Department: Science and Engineering
  6. Advisor(s): Mohammadi, Mohammad Reza
  7. Abstract:
  8. In present work, hydroxyapatite nano-rods are synthesized using a simple sol-gel method with calcium nitrate and potassium dihydrogenphosphate as calcium and phosphorus precursors respectively and ammonia was used for adjusting the pH=9. To obtain rod shape hydroxyapaite powder, multi wall carbon nanotubes were added to the solution, nHA powder was calcinated at 60 and 450 ℃. In second step, chitosan-gelatin/nanoHA solution were prepared by blending chitosan and gelatin in different concentrations with nanoHA powder, then the solution was freeze dried to maintain a composite scaffold. The prepared HA powder and bio-composite scaffold were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FT-IR) techniques in order to identify phase composition, microstructure and morphology, particle size and functional groups of them. Then porosity, water uptake, degradation rate of composite scaffolds in PBS and in vitro mineralization of composite scaffolds in 5 × SBF solution were determined. Regarding synthesized nano-hydroxyapatite, as we expected, XRD patterns showed that heat treatment increased crystallinity of powders, peaks were more distinct and width of peaks were not as broad as primary samples, calcium phosphate phase was common in both samples, this phase has biocompatible properties and its presence is advantageous for bone tissue engineering. FE-SEM images of nHA calcinated at 60 ℃ and 450 ℃ were almost the same with uniform dispersion and average diameter of 25 nm, FT-IR patterns showed functional groups which are characteristic bands of hydroxyapatite. In composite scaffolds, it was observed in FE-SEM images that nHA powder were dispersed in matrix uniformly, in presence of nHA porosity and pore sizes were decreased, moreover, FE-SEM images showed that higher amounts of gelatin decreased porosity and pore size of scaffolds. These observations are also supported by porosity measurement and swelling studies of composite scaffolds. It was realized that presence of nHA in composite scaffold improved its crystallinity and sharp peaks related to hydroxyapatite were observed in CG-nHA composite scaffolds
  9. Keywords:
  10. Chitosan ; Gelatin ; Scaffold ; Tissue Engineering ; Bone ; Sol-Gel Method ; Nanostructured Hydroxyapatite

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