Calcium phosphate cement incorporated with N-acetylcysteine-loaded silk fibroin microspheres: preparation and characterization

doi:10.3969/j.issn.2095-4344.2016.16.002

Abstract

Abstract:

BACKGROUND: Calcium phosphate bone cement has been applied to clinical surgery because of its good biocompatibility and osteoconduction. However poor mechanical properties and lack of osteoinductivity limit its wide application.
OBJECTIVE: To develop calcium phosphate cement incorporated with N-acetylcysteine (NAC) loaded silk fibroin microspheres (SFM), which is a kind of new injectable bone graft material with slow-release function, and evaluate its physical and chemical properties and cell compatibility.
METHODS: Empty SFMs were prepared with emulsion solvent evaporation to absorb NAC solution of different concentrations by NAC-SFM and the concentration of NAC at the maximum drug loading ratio was determined. Then, NAC-SFM was loaded into calcium phosphate bone cement to test the drug release properties in vitro. MC3T3-E1 osteoblasts were cultured on the surface of NAC-SFM calcium phosphate bone cement and cell attachment and growth were observed by scanning electron microscope. Additionally, MC3T3-E1 cells were cultured with three kinds of bone cement extracts (calcium phosphate cement, SFM-calcium phosphate cement, NAC-SFM-calcium phosphate cement, as well as cultured in the α-minimum essential medium containing a volume fraction of 10% fetal bovine serum and 1% penicillin-streptomycin double antibody as the control. MTS assay was used to evaluate cell proliferation.
RESULTS AND CONCLUSION: Microspheres in the composite bone cement presented with smooth surface, same size, diffused distribution and no obvious destroy. Thus, the SFM could remain stable in the reaction process of the composite bone cement. The double slow release system which contained silk fibroin microspheres and calcium phosphate bone cement showed a significant decrease in the cumulative release percentage of NAC within the first 24 hours compared with the control group (P < 0.05). In the next 28 days, the release speed of NAC was significantly lower in the NAC-SFM-calcium phosphate cement group than the calcium phosphate cement group (P < 0.05). In addition, different extracts had no significant cytotoxicity to the growth of MC3TC-E1 cells. Thus, the NAC-SFM-calcium phosphate cement has good cytocompatibility, which provide a new insight into the development of bone repair biomaterials.
中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Key words: Tissue Engineering, Biocompatible Materials, Calcium Phosphates

Jiang Lei, Pi Bin, Feng Tao, Li Bin, Lu Ying-jie, Yang Hui-lin, Zhu Xue-song. Calcium phosphate cement incorporated with N-acetylcysteine-loaded silk fibroin microspheres: preparation and characterization[J]. Chinese Journal of Tissue Engineering Research, 2016, 20(16): 2294-2302.

Figures/Tables 9

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