We define hydrogel as a polymer network containing a large amount of water or biological fluid in a 3-D structure. Because of the physical or chemical chains present in a hydrogel, it is stable in aqueous environment. Therefore, it has been used in diverse medical fields. In addition, by controlling the gelation degree of polymer solution (the state prior to hydrogel) hydrogels can be easily applied to damaged tissue area. This unique structure and properties of hydrogel shares a similarity with ECM (Extracellular matrix) in that it has a potential to be applied in tissue engineering field. Especially, the injectable property and ECM like structure can be applied to bone regeneration. Out of several polymers can be form hydrogels, silk fibroin (SF) has an excellent biocompatibility, biodegradability and it can be used to create bone regeneration scaffold in the form of hydrogel.
In this study, we fabricated a SF hydrogel containing hydroxyapatite nanoparticle (HAp). To improve the dispersibility of HAp in the SF aqueous solution, we chemically modified the surface of HAp particles using hyaluronic acid (HA) – dopamine (DA) conjugate. Since SF aqueous solution has a long term gelation time, we utilized ultra-sonication method to induce a rapid gelation. Stability of HAp in SF aqueous solution was measured by ELS and TGA. Finally, FT-IR and WAXD were used to evaluate the changes of secondary structure of silk hydrogel according to concentrations of hydroxyapatite nanoparticle concentration.

• Hyung Hwan Kim(Department of Biosystems and Biomaterials Science and Engineering, Seoul National University)
• Min Ji Kang(Department of Biosystems and Biomaterials Science and Engineering, Seoul National University)
• A Reum Park(Department of Biosystems and Biomaterials Science and Engineering, Seoul National University)
• Young Hwan Park(Department of Biosystems and Biomaterials Science and Engineering, Seoul National University)