Document Type : Full Research Paper


1 PhD, Tissue Engineering and Cell Therapy Group, School of Advanced Medical science, Tehran University of Medical Science

2 Professor, School of Biomedical Engineering, Amir Kabir University of Technology

3 Associate Professor, School of Biomedical Engineering, Amir Kabir University of Technology



During past decade, using biomimetic approaches has received much attention by scientists in the field of tissue substitutes preparation. These approaches have been employed for synthesis of bone tissue engineering scaffolds in the case of either materials or synthesis methods. In this study, an apatite phase has been synthesized within gelatin hydrogel in biomimetic condition. The obtained composite hydrogel has changed to a porous scaffold with the application of freeze drying technique in order to be used in bone tissue engineering. To characterize the chemical composition and crystal structure of the synthesized precipitate within hydrogel, FTIR, XRD and TEM analysis were used. Surface morphology and porous structure of the scaffold were studied with SEM. SEM analysis was also used to investigate the quality of cultured osteoblast cells activity. Results approved formation of an apatite phase within gelatin hydrogel in biomimetic condition with crystallite size ranging between 7-10 nm. Porosity percentage of the obtained nanocomposite scaffold was about 82% with pores sizes in the range of 100-350μm. Young’s elastic modulus of the scaffold was comparable with that of the spongy bone. The osteoblast cells cultured on the scaffold showed adhesion, immigration and extracellular matrix excretion on the scaffold internal surfaces. Thus, obtained results indicated the potential ability of the prepared biomimetic bone tissue engineering scaffold to be used in bone tissue repair process.


Main Subjects

[1]     Zhang S.M., Cui F.Z., Liao S.S., Zhu Y., Han L., Synthesis and biocompatibility of porous nanohydroxyapatite/ ollagen/alginate composite, J Mater Sci Mater Med, 2003; 14: 641-645.
[2]     Liao S.S., Cui F.Z., Zhu Y., Osteoblasts adherence and migration through three-dimensional porous mineralized collagen based composite: nHAC/PLA, J Bioact Compat Polym, 2004; 19: 117-130.
[3]     Kim H.W., Knowles J.C., Kim H.E., Hydroxyapatite and gelatin composite foams processed via novel freeze-drying and crosslinking for use as temporary hard tissue scaffolds, J Biomed Mater Res Part A, 2005; 72: 136-145.
[4]     Murugan R., Ramakrishna S., Development of nanocomposites for bone grafting, Compos Sci Technol, 2005; 65: 2385-2406.
[5]     Itoh S., Kikuchi M., Koyama Y., Matumoto H.N., Takakuda K., Shinomiya K., Tanaka J., Development of a novel biomaterial, hydroxyapatite/collagen (HAp/Col) composite for medical use, Bio-Medical Materials and Engineering, 2005; 15:29-41.
[6]     Kim H.W., Kim H.E., Salih V., Stimulation of osteoblast responses to biomimetic nanocomposites of gelatin-hydroxyapatite for tissue engineering scaffolds, Biomaterials, 2005; 26: 5221-5230.
[7]     Yamaguchi I., Tokuchi K., Fukuzaki H., Koyama Y., Takakuda K., Monma H., Tanaka T., Preparation and microstructure analysis of chitosan/hydroxyapatite nanocomposites, J Biomed Mater Res Part A, 2001; 55: 20-27.
[8]     Kikuchi M., Matsumoto H.N., Yamada T., Koyama Y., Takakuda K., Tanaka J., Glutaraldehyde cross-linked hydroxyapatite/collagen self-organized nanocomposites, Biomaterials, 2004; 25: 63-69.
[9]     Chang M.C., Tanaka J., FT-IR study for hydroxyapatite/collagen nanocomposite cross-linked by glutaraldehyde, Biomaterials, 2002; 23: 4811-4818.
[10] Azami M., Moztarzadeh F., Tahriri M., Preparation, characterization and mechanical properties of controlled porous Gelatin/Hydroxyapatite nanocomposite through layer solvent casting combined with freeze-drying and lamination techniques, Journal of Porous Materials, 2010; 17: 1380-2224.
[11] Parekh B., Joshi M., Vaidya A., Characterization and inhibitive study of gel-grown hydroxyapatite crystals at physiological temperature, Journal of Crystal Growth, 2008; 310: 1749–1753.
[12] Furuichi K., Oaki Y., Ichimiya H., Komotori J., Imai H., Preparation of hierarchically organized calcium phosphate–organic polymer composites by calcification of hydrogel, Science and Technology of Advanced Materials, 2006; 7: 219–225.
[13] Manjubala I., Scheler S., Bossert J., Klaus D., Mineralisation of chitosan scaffolds with nano-apatite  formation by double diffusion technique, Acta Biomaterialia, 2006; 2: 75–84.
[14] Ehrlich H., Krajewskab B., Hanke T., Born R., Heinemann S., Knieb C.h., Worch H., Chitosan membrane as a template for hydroxyapatite crystal growth in a model dual membrane diffusion system”, Journal of Membrane Science, 2006; 273: 124–128.
[15] Kniep R., Simon P., Fluorapatite-Gelatine- Nanocomposites: Self-OrganizedMorphogenesis, Real Structure and Relations to Natural Hard Materials, Top Curr Chem, Springer-Verlag Berlin Heidelberg, 2007; 270: 73–125.
[16] Watanabe J., Akashi M., Novel Biomineralization for Hydrogels: Electrophoresis Approach Accelerates Hydroxyapatite Formation in Hydrogels, Biomacromolecules, 2006; 7: 3008-3011.
[17] Azami M, Rabiee M., Moztarzadeh F., Glutaraldehyde Crosslinked Gelatin/hydroxyapatite Nanocomposite Scaffold, Engineered via Compound Techniques, polymer Composite, 2010; 31: 1987-2137.
[18] Gomes S., Boulon M., Oliveira A.L., Leonor I.B, Mano J.F., Reis R.L., Mineralization of Chitosan Membrane Using a Double Diffusion System for Bone Related Applications, Materials Science Forum, 2008; 587/588: 77-81.
[19] Ehrlich H., Hanke T., Born R., Fischer C., Frolov A., Langrock T., Hoffmann R., Schwarzenbolz U., Henle T., Simon P., Geiger D., Bazhenov V.V., Worch H., Mineralization of biomimetically carboxymethylated collagen fibrils in a model dual membrane diffusion system, Journal of Membrane Science, 2009; 326: 254–259.
[20] Bigi A., Boanini E., Panzavolta S., Roveri N., Rubini K., Formation of calcium phosphate/collagen composites through mineralization of collagen matrix, J.Biomed.Mater.Res, 2002; 59: 709-809.
[21] Maeda H., Kasuga T., Nogami M., Hibino Y., Hata K., Ueda M., Ota Y., Biomimetic apatite formation on poly(lactic acid) composites containing calcium carbonates, J.Mater.Res, 2002; 17: 727-730.