Fabrication of self-setting foam for bone graft material

磷酸钙泡沫是用于骨移植的材料。制备多孔HAP泡沫塑料的方法多种多样。在这些方法中，已知只有泡沫法允许类似松质骨的三维完全互连的多孔结构。但是，用泡沫法很难使这种泡沫与骨缺损的形状一致。小尺寸泡沫填充后相互硬化以缺陷清除此问题。我们尝试用小颗粒的α-TCP泡沫开发自凝泡沫。该α-TCP泡沫用NaH_2PO_4溶液或蒸馏水硬化。室温下NaH_2PO_4溶液凝固时间约为5 h， 200℃下蒸馏水凝固时间约为24h。凝固后的化学产物为NaH_2PO_4溶液的DCPD和蒸馏水的HAP。凝固后，α-TCP泡沫表面形成长度约为20 ~ 50 μm的针状晶体。针状晶体在凝固反应中相互渗透。这促成了与牙石膏相同的机制。

Calcium phosphate faom is exerent for bone graft material. Various methods are applicable for the fabrication of porous HAP foam. Among these method, only the foam method is known to permit three-dimensional fully interconnected porous structure similar to cancellous bone. But, it is very difficult to make this foam same as a shape of bone defect using foam method. Small size foam hardened each other after filling to the defect clear this problem. We tried to develop the self setting foam using small size particle of α-TCP foam. This α-TCP foam hardened with NaH_2PO_4 solution or distilled water. Setting time was about 5 hours at room temperature with NaH_2PO_4 solution, and 24hours at 200℃ with distilled water. Chemical product after setting was DCPD with NaH_2PO_4 solution, and HAP with distilled water. After setting, needle like crystals which length was about 20 to 50 μm were formed on the surface of α-TCP foam. Needle like crystals penetrated each other during the setting reaction. This contributed to set in the same mechanism as dental plaster.