Preparation and characterization of hydroxyapatite reinforced with hardystonite as a novel bio-nanocomposite for tissue engineering

Document Type: Research Paper

Authors

1 Department of Materials Engineering, Shahreza Branch, Islamic Azad University, Shahreza, Isfahan, Iran

2 Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran

10.7508/nmj.2015.02.006

Abstract

Objecttive(s):
Despite the poor mechanical properties of hydroxyapatite, its unique biological properties leads we think about study on improving its properties rather than completely replacing it with other biomaterials. Accordingly, in this study we introduced hydroxyapatite reinforced with hardystonite as a novel bio-nanocompositeand evaluate its in-vitro bioactivity with the aim of developing a mechanically strong and highly porous scaffold for bone tissue engineering applications.
Materials and Methods:
Natural Hydroxyapatite (NHA)-Hardystonite (HT) nanocomposite with different percentage of HT was synthesized by mechanical activation method and subsequent heating annealing process. This study showed that the addition of HT to HA not only increases the mechanical properties of HA but also improves its bioactivity. Dissolution curves presented in this study indicated that the pH value of SBF solution in the vicinity of HA-HT nanocomposite increases during the first week of experiment and decreases to blood pH at the second weekend. Hardystonite was composed of nano-crystalline structure with approximately diameter 40 nm. Specimens were composed of a blend of pure calcite (CaCO3) (98% purity, Merck), silica amorphous (SiO2) (98% purity, Merck) powder and pure zinc oxide (ZnO) with 50 % wt., 30 %wt and 20 %wt., respectively. These powders were milled by high energy ball mill using ball-to- powder ratio 10:1 and rotation speed of 600 rpm for 5 and 10 h. Then, the mixture mechanical activated has been pressed under 20 MPa. The samples pressed have been heated at 1100 ºC for 3 h in muffle furnace at air atmosphere. X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET performed on the samples to characterize.

Results:
According to XRD results, the sample milled for 10 h just indicated the hardystonite phase, while the sample milled for 5 h illustrate hardystonite phase along with several phases.
Conclusion:
In fact, our study indicated that hardystonite powder was composed of nano-crystalline structure, about 40 nm, can be prepared by mechanical activation to use as a new biomaterials for orthopedic applications.

Keywords


1. Jaiswal AK, Chhabra H, Kadam SS, Londhe K, Soni VP, Bellare JR. Hardystonite improves biocompatibility and strength of electrospun polycaprolactone nanofibers over hydroxyapatite: A comparative study. Mater Sci Eng C Mater Biol Appl. 2013; 33: 2926–2936.

2. Zreiqat H, Ramaswamy Y, Wu C, Paschalidis A, Lu Z, James B, Birke O, McDonald M, Little D, Dunstan CR. The incorporation of strontium and zinc into a calcium–silicon ceramic for bone tissue engineering. Biomaterials. 2010; 31: 3175–3184.

3. Ramaswamy Y, Wu C, Zhou H, Zreiqat H. Biological response of human bone cells to zinc-modified Ca–Si-based ceramics. Acta Biomater. 2008; 4: 1487–1497.

4. Zhang W1, Wang G, Liu Y, Zhao X, Zou D, Zhu C, Jin Y, Huang Q, Sun J, Liu X, Jiang X, Zreiqat H. The synergistic effect of hierarchical micro/nano-topography and bioactive ions for enhanced osseointegration. Biomaterials. 2013;  34: 3184e3195.

5. Wu  C. Methods of improving mechanical and biomedical properties of Ca-Si-based ceramics and scaffolds. Expert Rev Med Devic. 2009; 6: 237 – 241.

6. Ramaswamy Y, Wu CT, Zhou H, Zreiqat H. Biological response of human bone cells to zinc-modified Ca-Si-based ceramics. Acta Biomater. 2008; 4: 1487e97.

7. Wu C, Chang J, Wang J, Ni S, Zhai W. Preparation and characteristics of a calcium magnesium silicate (bredigite) bioactive ceramic. Biomaterials 2005; 26: 2925e31.

8. Mohammadi H, Hafezi M, Nezafati N, Heasarki S, Nadernezhad A, Ghazanfari S MH, pantafar M, Bioinorganics in Bioactive Calcium Silicate Ceramics for Bone Tissue Repair: Bioactivity and Biological Properties. J Ceram Sci Tech. 2014; 5(1): 1-12.

9. Chengtie Wu and yin Xiao, evaluation of the In VitroBioactivity of Bioceramics, Bone and Tissue Regeneration Insights. 2009; 2: 25–29.

10. Ji-Ho Park, Doug-Youn Lee, Keun-Taek Oh, Yong-Keun Lee, Kwang-Mahn Kim, Kyoung-Nam Kim. Bioactivity of calcium phosphate coatings prepared by electrodeposition in a modified simulated body fluid, Mater Lett. 206; 60: 2573–2577.

11. W. L. Tham, W. S. Chow, Z. A. Mohd Ishak, Simulated body fluid and water absorption effects on poly(methyl methacrylate)/hydroxyapatite denture base composites. eXPRESS Polymer Letters. 2010;  4(9):  517–528.

12. Pradnya N. Chavan, Manjushri M. Bahir, Ravindra U. Mene, Megha P. Mahabole, Rajendra S. Khairnar. Study of nanobiomaterial hydroxyapatite in simulated body fluid:Formation and growth of apatite, Materials Science and Engineering B. 2010; 168: 224–230.

13. Kokubo  T,  Takadama  H.  How  useful  is  SBF  in  predicting in  vivo bone bioactivity. Biomaterials. 2006; 27(15): 2907–15

14. Hench  LL.  Bioceramics:  from  concept  to  clinic. J  Am  Ceram  Soc. 1991; 74: 1487–510.