人類胚胎上顎間質細胞在不同無機鹽聚己內酯複合 材上之成骨細胞活性

Abstract

人工骨填補材種類繁多，可吸收高分子與生醫陶瓷所結合成的複合型骨填補材，在許多研究中均被證實可獲得兩類材料的優點與更多元的操作可塑性。聚己內酯其高度生物相容性已在動物實驗中獲得證實。在生物降解性藥物釋放載體及作為骨填補材支架的研究應用已相當廣泛，且有更優勢的價格及取得便利性。實驗設計以不同相的磷酸鈣鹽類生醫陶瓷，包括有 Hydroxyapatite 、Calcium Diphosphate 與Calcium phosphate dibasic，及傳統硫酸鈣類生醫陶瓷：二水合硫酸鈣，分別與聚己內酯共構成複合型骨填補材。經過多種溶劑及製程的嘗試，我們找出使用1,4 Dioxan為溶劑佐以冷凍乾燥法可製作出具有規則孔洞的三維立體支架。本實驗開發出能將複合型骨填補材製做為平整的二維薄膜、具有均勻孔洞的三維支架，使得材料可分別對應於骨缺損處覆蓋與填補。 在材料特性的檢測上，體外細胞實驗使用人類胚胎上顎間質細胞(human embryonic palatal mesenchymal cells)為實驗模型，觀察不同組合的材料，對於骨型成時期出現的ALP、 OC 、BMP-2 基因交互關係與骨引導性（osteoconductive）、骨誘導性（osteoinductive）。實驗中，細胞可在所有實驗組2-D平面薄膜貼附生長，生長速率卻無法達到培養皿同等水平，然而部分實驗組在初期時間點可誘導出400倍以上高量的ALP基因表現。但在動物實驗中發現，實驗組材料對於骨誘導再生與在斷層掃描下發現骨質密度並不理想，且在切片上有看到發炎細胞的存在，所以我們推測的原因為實驗組材料的吸收速率較實驗動物骨形成的速度慢，雖然材料具有骨引導性與骨誘導性，但在細胞生長所需空間的讓位上並不理想，所以可從加速材料的崩解並降低發炎反應時間的傾向上，再度對材料的製程做設計。

There are los of artificial bone grafts. It was proved in many experiments that combined type of high polymer and bioceramic bone grafts have more benefits and plasticities. The biocompatible characters of the polycaprolactone were proved in many animal experiments. And it was applicated frequently in drug-released carriers with low cost and using convenient. Based on the dynamic-balancing of bone apatite, we tried to rule out the bone healing effects of different phase of apatites and Calcium Sulfate, for find the good composite bone graft materials. The material characters of different kinds of Polycaprolactone composited bioceramics including Hydroxyapatite、Calcium Diphosphate、 Calcium phosphate dibasic and Calcium Sulfate were compared in this examination . After many trial and error, we figured out that good porous scaffolds could be fabricated by Freeze-dried method with 1,4 Dioxan as solvent. The human embryonic palatal mesenchymal cells was selected as cell mode for observing the osteo-induction 、 osteo-conduction effects and the serial expressions of bone related genes including ALP 、OC 、BMP2.We found that the cell adherence of our all materials can reach the level of the control dishes. We found that the cell adherence of our all materials can reach the level of the control dishes. And the high ALP expression was noted 24 days after cell seeding. But the CT scan bone densities in animal experiments of our all composite materials were not so good to our expectation. We suppose that the absorption rates of the materials were slower than the bony formation, and the degradable small polymer particle may cause enhanced inflammation effects.