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The Scientific World Journal
Volume 2014 (2014), Article ID 420616, 9 pages
Research Article

Effect of Gamma Irradiation on Structural and Biological Properties of a PLGA-PEG-Hydroxyapatite Composite

1Department of Dental Biomaterials, School of Dentistry, Tehran University of Medical Sciences, End of North Kargar Street, Tehran, Iran
2Department of Resin and Additives, Institute for Color Science and Technology, 55 Vafamanesh Street, HosseinabadSquare, P.O. Box 16765-654, Tehran, Iran
3Laser Research Center of Dentistry, School of Dentistry, Tehran University of Medical Sciences, End of North Kargar Street, Tehran, Iran
4New Technologies Research Center (NTRC), Amirkabir University of Technology, 424 Hafez Avenue, Tehran, Iran
5Iranian Center for Medical Laser Research, ACECR Tehran Medical Sciences Branch, Tehran, Iran

Received 7 June 2014; Accepted 31 July 2014; Published 8 September 2014

Academic Editor: Francesco Cilurzo

Copyright © 2014 Sima Shahabi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Gamma irradiation is able to affect various structural and biological properties of biomaterials In this study, a composite of Hap/PLGA-PEG and their ingredients were submitted to gamma irradiation doses of 25 and 50 KGy. Various properties such as molecular weight (GPC), thermal behavior (DSC), wettability (contact angle), cell viability (MTT assay), and alkaline phosphatase activity were studied for the composites and each of their ingredients. The results showed a decrease in molecular weight of copolymer with no change in the glass transition and melting temperatures after gamma irradiation. In general gamma irradiation can increase the activation energy ΔH of the composites and their ingredients. While gamma irradiation had no effect on the wettability of copolymer samples, there was a significant decrease in contact angle of hydroxyapatite and composites with increase in gamma irradiation dose. This study showed an increase in biocompatibility of hydroxyapatite with gamma irradiation with no significant effect on cell viability in copolymer and composite samples. In spite of the fact that no change occurred in alkaline phosphatase activity of composite samples, results indicated a decrease in alkaline phosphatase activity in irradiated hydroxyapatites. These effects on the properties of PLGA-PEG-hydroxyapatite can enhance the composite application as a biomaterial.