Abstract:

Objective The aim of the present study was to design and fabricate a three dimensional（3D） porous structure of silk fibroin/apatite used as a potential scaffold in bone tissue engineering. Methods With the combining use of non- woven silk fibroin net and biomimetic method, porous non - woven silk fibroin/nano- hydroxyapatite net （NSF/nHAP）was prepared and characterized with X- ray diffraction（XRD）, scanning electron microscope（SEM） and fourier transform infrared spectroscopy（FTIR）. The porosity and swelling ratio of the 3D scaffold were also measured. Besides, the osteoblasts from the cranium of new born SD rat were cultured on the pre - fabricated scaffold to evaluate the biological reaction of the scaffold. Results The nano- sized hydroxyapatite crystals were needle- like with the length of 100- 300 nm and the diameter of 20- 60 nm. The scaffold fabricated in the present study exhibited the porous microstructure with open porosity around 70%- 78%. Its average pore size was about（163.4±42.6）μm. The swelling ratio and water uptaking were 4.56% and 81.93%, respectively, which revealed that the 3D porous scaffold had an excellent hydrophilicity. The rod- shaped apatite crystals could rapidly form on the surface of fibroin fibers throughout the network by immersing the net into calcium and phosphate solutions alternatively. Conclusion A 3D porous NSF/nHAP scaffold can be fabricated by biomimetic mineralization and none- woven silk fibroin method. The novel NSF/nHAP scaffold has an excellent cytocompatibility for the growth of osteoblasts. Porous NSF/nHAP scaffold may be a hopeful biomaterial used in bone tissue engineering.

Key words: fibroin, biomineralization, hydroxyapatite