- 學位論文
溫感性水膠搭載藥物對骨髓間葉幹細胞硬骨分化之影響探討
The Effect of Thermosensitive Hydrogel Carrying Drugs on The Osteogenesis of Bone Marrow Mesenchymal Stem Cells
摘要
骨質疏鬆症主要症狀為骨質流失、骨密度下降，導致骨折發生。本研究目的在評估骨髓間葉幹細胞(mesenchymal stem cells, MSCs) 受dexamethasone (Dex) 、雙磷酸鹽類Alendronate (Ale) 或樹枝狀高分子poly (amidoamine) (Pamam) 搭載Ale (Paman-Ale) 等藥物作用，混合氫氧基磷灰石(Hydroxyapatite, HA) ，包覆於mPEG-PLGA溫感性水膠中；在二維、三維培養環境下進行硬骨分化之影響；並探討MSCs、誘導分化藥物及水膠在糖皮質類固醇所誘發之骨質疏鬆症小鼠的治療成效。硬骨分化實驗結果發現以100 nM Dex、100 nM Ale及10 nM Pamam-Ale能提升MSCs之鹼性磷酸酶(Alkaline phosphatase, ALP)活性及ALP、第一型膠原蛋白基因表現，其中以Pamam-Ale效果最佳；添加HA或包覆水膠後，則以Ale提升ALP表現量最佳，Dex促進鈣沉積為高。將分化藥物、MSCs、HA和水膠製備成複合性材料，注入骨質疏鬆症小鼠股骨內，透過骨密度及骨組織切片染色，發現治療組與控制組的皮質骨骨密度並無統計上顯著差異，但治療組海綿骨骨密度增加；由組織染色可觀察到HA 分佈於皮質骨內且能減少海綿骨空隙。本研究結果證明MSCs 、HA 、Ale 和水膠組成之複合性材料具骨誘導分化及修復骨缺損能力。
並列摘要
The major symptoms of osteoporosis are bone loss and decreasing bone mineral density, which eventually lead to bone fracture. The specific aims of the study were to evaluate the effect on osteogenesis of mesenchymal stem cells (MSCs) in two or three-dimensional culture environment with the supplements of dexamethasone (Dex), bisphosphonate drug Alendronate (Ale) or dendrimer poly(amidoamine) (Pamam) loaded with Alendronate (Pamam-Ale), and combined with hydroxyapatite (HA) and mPEG-PLGA thermoreversible hydrogel. The therapeutic effect in osteoporosis mice induced b glucocorticoid by using the combination treatment of MSCs, osteogenic inducing drugs and hydrogel was also observed. The results from osteogenic induction showed that 100 nM Dex,100 nM Ale and 10 nM Pamam-Ale could enhance alkaline phosphatase (ALP) activity and ALP and type I collagen gene expression. Highest level of ALP activity was found in the group of Pamam-Ale. When in combining with HA or hydrogel, highest level of ALP activity was found in the group of Ale and highest level of calcium deposition was seen in the group of Dex. The results from the femurs of osteoporosis mice injected with the combination of osteogenic inducing drugs, MSCs, HA and hydrogel found that no significant difference in the bone mineral densities of cortex bones between control and treatment groups. But the bone mineral densities of spongy bones from the treatment groups were higher than those of control group. Tissue sections showed that HA was distributed in the cortex bone and the porosity decreased in the spongy bone. In summary, the combination of osteogenic inducing drugs, MSCs, HA and hydrogel has the potential in osteoinduction and may be applied in bone defect repair.