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Mechanical Properties of Biomimetic Composites for Bone Tissue Engineering

Published online by Cambridge University Press:  01 February 2011

Devendra Verma
Affiliation:
Civil Engineering, North Dakota State University, Fargo, ND 58105
Kalpana S. Katti
Affiliation:
Civil Engineering, North Dakota State University, Fargo, ND 58105
Bedabibhas Mohanty
Affiliation:
Civil Engineering, North Dakota State University, Fargo, ND 58105
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Abstract

A biomimetic process involving in situ mineralization of hydroxyapatite (HAP) is used to design new composite biomaterials for bone tissue engineering. Surface and bulk properties of HAP composites have been studied for hydroxyapatite mineralized in absence (ex situ) of polyacrylic acid (PAAc) and in presence (in situ) of PAAc. XRD studies show existence of structural disorder within in situ HAP. It has been observed that PAAc increases the rate of crystallization. FTIR studies indicate calcium deficiency in structure of both in situ and ex situ HAP. PAAc provides favorable sites for nucleation of HAP. During crystallization of HAP, PAAc dissociates to form carboxylate ion, which binds to HAP. Porous and solid composites of in situ and ex situ HAP with polycaprolactone (PCL) in 50:50 ratio have been made to evaluate their applicability as bone scaffold. Mechanical tests on solid samples indicate ex situ HAP/PCL composites have higher elastic modulus (1.16 GPa) than in situ HAP/PCL composites (0.82 GPa). However, in case of porous composites, in situ HAP/PCL composites are found to have higher elastic modulus (29.5 MPa) than ex situ HAP/PCL composites (10.4 MPa). Nanoindentation tests were also performed at different loads to evaluate mechanical properties of the composites. In situ HAP mineralized using non-degradable polymers has thus been shown to improve mechanical response in porous composites.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1. Mann, S., Archibald, D. D., Didymus, J. M., Douglas, T., Heywood, B. R., Meldrum, F. C., Reeves, N. J.. Science 2611, 286 (1993).Google Scholar
2. Vincent, J. F. V.. Proc. of the 4th European Conf. on Smart Struct. and Mat., Harrogate, UK, 1998, pp. 17.Google Scholar
3. Srinivasan, A. V.. Materials Science and Engineering C 4, 19 (1996).Google Scholar
4. Katti, K. S.. Colloids and Interfaces B 39, 133 (2004).Google Scholar
5. Yasuda, H. Y., Mahara, S., Umakoshi, Y., Imatazo, S., Ebisu, S.. Biomaterials 21, 2045 (2001).Google Scholar
6. Lorenzo, L. M. R., Regi, M. V., Ferreira, J. M. F.. Biomaterials 22, 583 (2001).Google Scholar
7. Dalas, E., Kallitsis, J. K., Koutsoukos, P. G.. Langmuir 7, 1822 (1991).Google Scholar
8. Skrtic, D., Eanes, E. D.. Calcified Tissue International 50, 55 (1992).Google Scholar
9. Zhang, L. J., Liu, H. G., Feng, X. S., Qian, D. J., Zhang, L., Yu, X. L., Feng, Q. L.. Thin Solid Films 458, 287 (2004).Google Scholar
10. Kato, K., Eika, Y., Ikada, Y.. Journal of Materials Science 32, 5533 (1997).Google Scholar
11. Katti, K., and Gujjula, P.. Mat Res Soc Symp Proc 711, GG4.3.1-G4.3.6 (2001).Google Scholar
12. Coombes, A. G. A., Rizzi, S. C., Williamson, M., Barralet, J. E., Downes, S., Wallace, W. A.. Biomaterials 25, 315 (2004).Google Scholar