金屬離子裁控聚多巴胺塗覆鈦植體的抗菌活性及生物性質

在鈦植體表面開發新的方式，來避免細菌的附著及促進細胞的生長，是非常需要的。為此，不同的金屬離子（銀，銅，鍶 或鋅），被用來噴濺在聚多巴胺附著的鈦金屬表面上。實驗的目的在檢視金屬離子塗層對革蘭氏陰性的大腸桿菌，革蘭氏陽性的金黃葡萄球菌的抗菌活力，以及對細菌作用所產生的活性氧類的反應內容。L929, RAW 264.7 和人類間質幹細胞則用來分析離子塗層的生物功能。在相組成及微結構的實驗結果，顯示出金屬離子成功的塗佈在聚多巴胺附著的鈦金屬表面 ; 三種二架的金屬離子塗層以濃度相關性的模式，有效的抑制了細菌的生長。和負對照組比較起來，銅，鍶以及鋅離子在大腸桿菌和金黃葡萄球菌上多產生了三到八倍的活性氧類。由不良的細胞活力及分 化顯示，銅和銀的存在明顯地降低了細胞功能。相反的，高含量的鍶，則可以促進人類間質幹細胞的增生和分化。最後，考慮到抗菌能力及成骨活動，用 10% 鍶塗佈的鈦在植體的運用上是有潛力。

There is a great need to develop new approaches for preventing bacterial adhesion and promoting cell growth on the surface of Ti implants. To this end, various metal ions (Ag+, Cu2+, Sr2+ or Zn2+) were sprayed onto the surface of the PDA (polydopamine)-immobilized Ti. The antibacterial activity of metal ion coatings against Gram-negative E. coli and Gram-positive S. aureus were examined. The content of reactive oxygen species (ROS) production from the metal ions in bacteria was also determined. L929, RAW 264.7 and human mesenchymal stem cells (hMSCs) were used to analyze biological function of the coatings. The results of phase composition and microstructure showed that metal ions were successfully coated on PDA-immobilized Ti surface. Three divalent metal ion coatings effectively inhibited bacterial growth in a concentration-dependent manner. Samples of Cu, Sr and Zn ions in E. coli and S. aureus produced 3-8 times more ROS than the negative control. The presence of Cu and Ag remarkably reduced the cell function, as evidenced by poor cell viability and differentiation. In contrast, high content of Sr promoted hMSC proliferation and differentiation. It is eventually concluded that, taking antibacterial ability and osteogenic activity into account, 10% Sr-coated Ti had potential for implant applications.