氫氧基磷灰石由於具有骨引導性質，應用於硬組織修復已經有數十年的歷史，鋅元素具有刺激骨母細胞分化和增生，且促進骨質成長的功能。天然高分子幾丁聚醣有良好的生物性質如生物可降解性，可作為生醫材料如藥物釋放微粒、牙周組織修復、細胞支架等。本研究以溶膠凝膠法合成磷灰石，並在容膠溶液中調整pH值，後續並添加氧化鋅加以燒結處理，以冷凍乾燥技術滲覆幾丁聚醣於含氧化鋅之磷灰石製作出類似骨質複合結構的無機-有機複合塊材，分析基本性質及浸泡行為，以期作為骨缺損修補材。結果發現X光繞射顯示出以溶膠凝膠法製作的原料需要經過500℃的熱處理才能得到磷灰石晶相結構，但溶膠酸鹼值調至9時則可以300℃低溫合成磷灰石。未調整pH塊材的徑向拉伸強度為3.8MPa，明顯(P<0.05)低於pH9的塊材(5.3MPa)。氧化鋅對於徑向拉伸強度沒有顯著影響，但是以×光繞射分析發現氧化鋅使得磷灰石的(002)結晶面強度變寬。在體外浸泡實驗發現，塊材拉伸強度急速降低，在3天後損失達40%~50%，顯示具統計差異(P<0.05)，之後維持穩定值。本研究中將混合溶膠溶液調整至較高pH值時，的確可以將磷灰石合成溫度降低至300℃，並且有較高起始的徑向拉伸強度。
In the past several years, hydroxyapatite (HA) ceramics have been extensively used as bone graft substitutes because of their osteoconductivity. Zinc promotes proliferation and differentiation of osteoblast cells and acts as a stimulator of bone growth. Naturally polymeric chitosan has many good biological properties including biodegradation. This makes chitosan useful in biomedical applications such as micropheres, membranes, and scaffolds. We prepared Zn-containing apatite/chitosan composite, which is similar to chemical composition of bone tissue, using a sol-gel route and freeze-drying method. X-ray diffraction patterns show that apatite phases can be obtained at 50000 for control condition. For those in which precursor solution with pH 9 were used, lower temperatures (300℃) sufficed. The tensile strength of monolithic apatite derived from the sol-gel processing at pH 9 (5.3 MPa) wassignificantly higher (P<0.05) than that of samples without pH adjustment (3.8 MPa). We did not find that adding ZnO significantly affected strength value, though oriented growth of the HA phase on the (002) plane was enhanced. Incorporation of chitosan into bioceramic bulks did not affect strength value. Tensile strength decreased rapidly by 40%~50% (P<0.05), after immersion in Hank's solution for 3 days, after which strength stabilized. In conclusion, by adjusting the precursor solution to a pH 9, the temperature needed for apatite synthesis can be reduced to 300℃, resulting in a higher initial tensile strength.
