| 摘要: | 為了使鈦與骨組織之間有更好的生物鍵結，許多學者把研究目標著重於鈦的表面鍍上一層具有生物活性的鈣磷增加鈦的生物活性。本實驗將鈦試片進行微弧氧化處理，讓試片表面先反應形成一層含有鈣磷成分的多孔二氧化鈦層，再將試片進行後處理。處理的方法有:1.家用微波2.商用微波3.水熱法4.額外將試片浸泡於二次水(DD)、鈣磷液體(CP)液體中，溫度設為兩種，常溫下浸泡CP液體30分鐘和DD、CP液體沸騰到100度時再浸泡30分鐘，測試是否能利用這樣方法析出結晶物。目的是希望藉由4種不同方法找出最有效迅速的表面改質。試片製作完後會以掃描式電子顯微鏡、傅立葉紅外線光譜儀、X光繞射儀、接觸角量測儀、表面粗糙度儀來觀察與分析。本研究結合微波跟水熱的優點發現使用商用微波溫度在200℃微波時間是30分鐘時，溶液是二次水或稀鈣磷液體這兩皆能在微弧氧化鈦試片表面上析出奈米尺寸鈣磷結晶物，相較於傳統水熱法3小時大幅縮短處理時間。推測是因為透過微波可以快速提供分子動能、快速傳遞能量提升反應速率。在表面氧化層的粉末經紅外線吸收光譜分析(FTIR)有偵測到波長在幾個特定區被吸收掉，分別是磷酸根和氫氧根及二氧化鈦，經過商用微波處理所析出的尖峰較尖銳，比家用微波還來的明顯，藉由被吸收的區域來判斷。相結構方面水熱法可以析出氫氧基磷灰石結晶，而在MARS-DD-30、MARS-CP-30、MARS-CP-30-9.6、MARS-CP-30-11這幾組可以找到有相同尖峰，但沒有像水熱法那麼尖銳。我們的結果顯示細胞黏附程度是隨著培養時間增長而增加，種植時間有4小時和1天，細胞經商用微波後1天的量比4小時多與對照組純鈦試片相比明顯多很多，依貼附的量由多到少組別是商用微波處理,家用微波處理,純鈦試片。在種植1天所觀察到的結果是家用微波處理的細胞貼附型態呈現球狀，較直立，而商用微波的4小時的細胞平坦貼附，顯示使用商用微波處理4小時比家用微波1天效果來的好，是可以在短時間之內製造出讓細胞貼附得很好的環境。同時也證明細胞生長在MARS-CP環境，與家用微波處理及純鈦試片相較之下貼附效果及活性都比較好。透由商用微波處理在MARS-CP-30、MARS-CP-30-9.6、MARS-CP-30-11這些含有鈣磷成分的組別的接觸角比MARS-DD-20、MARS-DD-30二次水的試片角度還要來的較低，且角度接近水熱法試片，約22度，在製備時間縮短許多時間卻得到接近的角度。
結論是藉由商用微波處理照射在微弧氧化鈦試片上在時間半小時，溫度約150度時是幾乎沒有析出物，但在200度時，可以成功的在二氧化鈦孔洞周圍製造出約100奈米尺寸的結晶析出物，析出的量明顯的比家用微波處理的多，顯示結晶必須要到達在固定一個溫度後才會開始有出析，且在鈣磷環境下隨著pH值上升所析出的型態也不相同，會從只有單一奈米結晶析出到奈米和微米複合物析出。本研究貢獻在於利用商用微波短時間照射可以在短時間之內製造出奈米加上微米尺度的環境，且達到跟水熱法接近的親水性角度及更好的初期細胞貼附及細胞活性，跟水熱法相比在製作時間上縮短了許多。
Purpose
Nano-sized calcium phosphates (CaPs) coatings on biomaterials are gaining attentions as nano-structured surfaces enhance the cellular activity more than surface along with micron-sized structure. The hypothesis of this research is that nano-sized CaPs can be precipitated on the anodic oxidized titania porous surface via a microwave irradiation (MW) and commercial microwave irradiation(MARS) process.
Materials & Methods
The titania porous surface was prepared by (micro-arc-oxidation，MAO ) (280V, 10mA/cm2) of grade 2 commercial pure titanium discs in electrolytes composed of 0.2M calcium acetate and 0.04M β-glycerol phosphate disodium for 3mins. The titanium discs were microwave irradiated in water (MW-DD) and diluted Ca/P solutions (MW-CP) by a domestic microwave oven (2.45GHz,1000W, 50%) 20 minutes. The morphology,structure, and chemical characters of samples were evaluated by SEM, XRD and FTIR, the results were compared to hydrothermal (HT, 250℃, 2.5hours) and control uncoated titanium group.
Results
By SEM, numberless nano-sized CaPs precipitates on titania porous surface were obtained on MW-CP -20sample,whereas no precipatate was found on MW-DD-20 samples. The nano-sized precipitates are shuttle-like with long axis around 100nm . There are various micron-sized hexagonal rod-like precipitates were found by HT-DD-2.5hr and HT-CP-2.5hr. The XRD shows weak hydroxyapatite (HA) peaks at MARS-CP-30 series samples, andFTIR shows broaden Ti-O, PO3-4, and OH- absorption peaks indicates the Ca and P which originally incorporated in the anatase titania were leach-out to precipitate CaPs homogeneously on the porous surface by MARS. The XRD of HT samples shows 25.88°, 31.72°,32.19. 32.96° of HA peaks beside anatase and titanium peaks. The FTIR of HT shows sharp absorption peaks of PO3-4 at 566, 604, 1050,1092 cm-1 also confirmed that HA abtained by HT can possess highly crystalline.The MG63 cells seeded in samples 4 hours and 1 day ﹐and show MARS-CP series samples have good adhesion than MW series samples and control group.
Conclusion
Nano-sized CaPs precipitates on titania porous surface were obtained via a commercial microwave irradiation (MARS) process. Hopefully the nano-sized CaP precipitates firmly formed on the micron-sized porous titania would benefit to the protein adsorption and osteoblasts differentiation and shortening the osseointegration time. |
