人工植體材料與表面性質對於骨髓幹細胞之活性與骨分化潛能評估

The Influence of the Material and Surface Properties of Dental Implants on the Behaviors of the Bone Marrow Stem Cells

蔡晴伃(Tsai Ching Yu)

指導教授 ： 張博鈞

國立臺灣大學/醫學院/臨床牙醫學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202103771

摘要

中文摘要
人工植牙為目前牙科重建的治療選擇之一，而骨整合（osseointegration）則是確保人工植體治療成功的要件。過去研究顯示噴砂後酸蝕處理（sandblasted and acid-etching; SLA）的植體複合表面對人體組織親和力良好，並可加速骨整合。進一步在SLA製程中使用氮氣、並保存於等張溶液的製程（modified SLA），亦是臨床選項之一。近年來植體材質在四級鈦中添加鋯（zirconia）以提升植體機械強度。但這些材料對骨整合的優缺點並未被詳細探討。本實驗目的為在體外實驗中探討植體金屬或表面性質對人體幹細胞成骨反應的影響。
本實驗檢測人體骨髓幹細胞在兩種植體材質（純鈦或鈦鋯合金）上施加三種表面處理（拋光、SLA處理、modified SLA處理）上之細胞活性與骨分化能力。將幹細胞培養於六種表面上，經過第一、三天後使用Alamar Blue assay量化細胞生長狀況，並以免疫螢光染色法觀察細胞F-actin 與vinculin分布情形；於第七、十天使用Alizarin red assay量化礦化產物；於第一、四天使用RT-PCR確認Rock2及Runx2基因表現量。
實驗結果顯示，modified SLA對水接觸角為零，親水性表現比另兩者皆有顯著改善。SLA純鈦、SLA鈦鋯、modified SLA純鈦、modified SLA鈦鋯表面粗糙度數值分別為2.26±0.12, 2.21±0.27, 1.67±0.12, 2.64±0.21微米，顯著比拋光表面粗糙。免疫螢光染色顯示拋光表面細胞之面積顯著較其餘組別大；modified SLA表面在第七天較其餘組別顯著較多礦化物沉積，且在第十天時，經表面處理後之金屬顯著高於拋光表面組別的礦化物沉積；同樣的，在RT-PCR中，modified SLA鈦鋯有最高的Runx2及Rock2基因表現量，亦顯著高於modified SLA純鈦的基因表現量。
總結以上，SLA及modified SLA處理的表面，提高表面粗糙度後加速成骨相關基因表現量和礦化基質沈澱。而modified SLA處理後的鈦鋯合金比起純鈦合金有更佳的初期促骨分化表現。

關鍵字

骨整合 ； 幹細胞 ； 成骨分化能力 ； 牙科植體表面處理

並列摘要

Abstract
Background: Dental implants are one of the major treatment options in oral rehabilitation, and osseointegration is the major success criteria of the implantation. Surface modification by sand-blasting and acid-etching (SLA) had been shown to achieve a high level of osseointegration, and a further modified hydrophilic SLA surface has been also clinically available. Additionally, a titanium-ziroconia alloy (Ti-Zr), presenting good biocompatibility and higher yield strength to Ti, has been used as an alternative material for dental implants. Although modern material alloys and surface modification technologies have been introduced, the influence on osseointegration has not been fully investigated yet.
Objective: The aim of the study was to evaluate the influence of materials and surface properties of dental implants on osseointegration in vitro.
Materials and Methods: Machined, SLA and modified SLA surface treatments on two different bulk materials, titanium (Ti) and titanium-zirconium (TiZr) alloy, were utilized, and the surface roughness and hydrophilicity, were evaluated. Human bone marrow stem cells (BMSCs) were seeded on the material respectively. The cell viability was evaluated by the Alamar Blue assay, the cell behaviors were evaluated by the DAPI with fluorscent phalloidin for F-actin and anti-vinculin antibody, and the osteogenic potential was quantified by the Alizarin red assay. The expressions of Rock2 (cell motility gene) and Runx2 (osteogenic gene) were further examined by the realtime PCR.
Results: Modified SLA Ti and TiZr groups were hydrophilic, and the roughness values of machined Ti, machined TiZr, SLA Ti, SLA TiZr, modified SLA Ti ,and modified SLA TiZr groups were 0.54±0.3, 0.12±0.01, 2.26±0.12, 2.21±0.27, 1.67±0.12, 2.64±0.21 𝜇m. Immunofluorescence staining showed that cell area was significantly reduced in SLA and modified SLA Ti and TiZr groups. On modified SLA surfaces, mineralization was significantly promoted on Day 7 and was significantly greater on TiZr discs relative to the Ti discs at Day 10. On the modified SLA surfaces, TiZr discs also significantly upregulated Runx2 and Rock2 genes relative to Ti discs on Day 1
Conclusion: SLA and modified SLA treatment increased surface roughness to modulate the behaviors of BMSCs. On the modified hydrophilic SLA surfaces, TiZr alloy appeared to promote osteogenic potential of BMSCs relative to the Ti.

並列關鍵字

osseointegration ； immediate dental implant loading ； cell adhesion ； mesenchymal stem cells ； zirconium

參考文獻

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