Preliminary Study On Artificial Bone Fabricated With Silk And Shell

In order to explore the feasibility to use the silk fibroin material and shell powderfor artificial bone preparation, the bombyx mori posterior silk gland originated fibroin protein sources and Anodonta shells powder are mixed and shaped in the self-forming mold, and then the cylindrical solid materials are prepared as artificial samples for test. In this study, experimental results obtained are as follows:﹙1﹚the material of posterior silk gland dissolved in the water medium to obtain the silk fibroin, then freeze-dry the solution, and then white floss like silk fibroin gained eventually. The pick-up rate of silk fibroin is 0.33 g / head. By mechanical grinding method, the particle size distribution of silk fibroin powder range from 100-400μm, and 54% of the particle size of which was about 200μm.﹙2﹚ The artificial samples process skin irritation test, allergy test, acute animal (single dose) toxicity, skin irritation test, hemolysis test, and the experimental results show that the bone of the test indicators are in line with medical equipment requirements classⅢ.﹙3﹚The artificial bone has a honeycomb internal structure, uniform pore distribution, and pore diameter ranging between 5-60μm. The particle diameter of material is about 5μm through the scanning electron microscope image.﹙4﹚The porosity of the samples is between 8.03% ~ 21.18%, and their density is between 1.22- 1.88g/cm3. With the increasing of SF content, porosity increases gradually, When the porosity is 70%, it reached the maximum, then gradually decreased.﹙5﹚The mechanical test showed that with the content of silk fibroin of the samples increased, the elongation at break showed a gradual upward trend, when the content is less than 30%, the material can easily break. With content of silk fibroin of the sample increased, compression modulus and flexural modulus decreased gradually in the trend, when the content is less than 50%, the downward trend even more pronounced.﹙6﹚Fourier transform infrared analysis showed that the absorption peak of silk fibroin and shell powder simultaneously appeared in the target material, but it appears the band changed, indicating that not only two materials blended physically, but also a number of chemical bonds connected.﹙7﹚Thermal stability test showed that the sample in the temperature only appeared water evaporation, no phase change range 160℃. In summary, The preparation method of posterior silk gland silk fibroin material in this study is simple and has high yield; the internal structure of artificial bone materials, mechanical properties and Biological safety indicators prepared in this study meet the requirements of artificial bone; also has good thermal stability, and can withstand heat sterilization temperature.