現今由於受限於自體移植的短缺與異體移植的免疫排斥現象，人工合成的生醫材料需求量日漸增加，其中骨組織工程支架最佳的製備條件就是要與人體自然骨組織的成份與結構相仿，人體骨頭是由氫氧基磷灰石與膠原蛋白所組成，且兩者會順著骨骼所受的最大應力做方向性排列。如果於支架內添加鍶鈣磷的成份，有助於抑制骨吸收及促進新骨形成，更適合應用於骨質疏鬆之患者；而含有明膠成份之支架則較容易控制其孔洞結構。因此本研究利用共沉澱法直接於明膠溶液內合成三種不同濃度(S3CP、S5CP、S6CP)鍶置換鈣磷化合物，使兩者能夠均勻的混合，再經由單向性冷凍乾燥製備出具有方向性孔洞之複合材料支架。由電子顯微鏡與微形電腦斷層掃描觀察到支架均具有單一方向的孔洞，孔洞大小約200 m到400 m，適合骨組織工程支架的需求。透過能量散射光譜儀分析、傅立葉轉換紅外線光譜儀與X光粉末繞射儀，可知合成的鈣磷化合物主要由氫氧基磷灰石組成，且鍶離子有參雜進入其結構。支架進行交聯反應後，各組交聯指數都可達到約80%，可視為交聯完全，降解速率測試經過35天，重量損失約20%。當鍶鈣磷化合物含量增加，孔洞率會有下降的趨勢。由抗壓強度測試發現縱向較橫向強2至3倍，與人體自然骨相仿具有順向性結構之特性。於體外細胞培養，可觀察到類骨母細胞(MG63)貼附形態良好，經由靜態與改良之動態培養可知含鍶的S5CP支架最適合培養細胞。由上述結果，本研究所製備的鍶置換之單向多孔性支架可應用於骨組織工程。

Recently, the demands for the use of artificial materials in the biomedical field have increased significantly due to the limited accessibility of autografts as well as the immune responsie associated with allografts. The best conditions for bone tissue engineering scaffolds are to stimulate the content and structure of human bone. The hydroxyapatite and collagen comprise the main component of human bone, and highly ordered hierarchical structure. Strontium and calcium phosphate can inhibit bone resorption and enhance new bone formation, especially for low bone density patients. Gelatin is often used to produce scaffolds, since it has good flexibility to control the pore structure. In this study, the even gelatin-calcium phosphate nanocomposite were fabricated by the co-precipitation of three different concentrations of calcium phosphate within a gelatin sol (S3CP, S5CP, S6CP). Then porous scaffolds with microtubule orientation structure were manufactured by unidirectional freeze-drying technology, and aligned porous structure was characterized by SEM. Pore sizes in the range 200-400 m, are generally considered as a good requirement for bone tissue engineering. The composite was characterized using an Energy Dispersive Spectrometers (EDS), Fourier Transform Infrared Spectrometer (FTIR) and X-ray Diffraction (XRD). The calcium phosphate compounds composed mainly of hydroxyapatite, and result showed the Sr-HA has mixed phase. The crosslinked scaffolds resulted to 80% crosslinking index and degradation study showed that the scaffolds degraded about 20% after 5 weeks. The porosity of scaffolds decreased with increasing calcium phosphate concentration and the compressive strength in the longitudinal direction was 2-3 fold higher than transverse direction, the same as nature bone structure feature. In vitro, MG63 cell showed good attachment on the scaffold. In addition, containing strontium of S5CP scaffolds by using static culture and optimized dynamic culture are most suitable scaffolds for cell viability. As a result, the gelatin-calcium phosphate nanocomposite scaffolds have great potential for use as bone tissue engineering.

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