不同孔隙率的三維多孔二氧化鈦對於脂肪幹細胞分化為成骨細胞及脂肪細胞之影響

Abstract

將氯化鈉與二氧化鈦粉末依照不同體積比例混合，利用燒結法製備出三維之多孔二氧化鈦，接著將脂肪幹細胞種植於二氧化鈦試片上，誘導脂肪幹細胞分化成為成骨細胞及脂肪細胞，探討不同孔隙率的二氧化鈦試片對於脂肪幹細胞分化能力之影響。本實驗利用X光繞射(X-ray diffraction, XRD)、掃描式電子顯微鏡(scanning electron microscopy/energy dispersive spectroscopy, SEM)，分析燒結後之二氧化鈦試片其結晶構造及表面形貌。XRD結果顯示混合的粉末在經過1300℃/4 h燒結後，並沒有產生其他化合物，均是純的二氧化鈦。在SEM方面，觀察試片正面及側面的孔洞大小及形貌，隨著氯化鈉體積比的增加，二氧化鈦的孔洞有形顯增加，甚至大於原本氯化鈉顆粒體積，在孔隙率方面，隨著氯化鈉體積增加，孔隙率上升。

在脂肪幹細胞培養及分化的部分，從Fluorescein Diacetate(FDA)螢光圖中可觀察到脂肪幹細胞皆有附著在二氧化鈦試片上，再由多功能微量盤分析儀計算得試片上之細胞數皆有成長趨勢，表示二氧化鈦對於脂肪幹細胞沒有細胞毒性。接著進行脂肪幹細胞分化，首先觀察脂肪幹細胞分化為成骨細胞之情況，從定量即時聚合酶鏈鎖反應(qPCR)所測得之基因表現中發現，種植於二氧化鈦上的脂肪幹細胞在二氧化鈦試片上，與培養皿相比，分化效果不佳；另外也測試脂肪幹細胞在二氧化鈦試片上分化為脂肪細胞的效果，在長時間的培養後，二氧化鈦上的脂肪細胞基因表現皆明顯優於培養皿上的脂肪細胞，表示其分化效果優於培養皿。另外利用油滴染色，證實了二氧化鈦試片及培養皿上均有脂肪細胞生成。

由本實驗可得知二氧化鈦試片對於脂肪幹細胞分化為成骨細胞，其效果並不佳，然而若將脂肪幹細胞分化為脂肪細胞，其分化效果比培養皿佳，此表示二氧化鈦試片適合用來使脂肪幹細胞分化成脂肪細胞。

The samples were prepared with various content of sodium chloride and titanium dioxide powder at different volume percent, then sinter the samples at 1300°C for 4 hours for a three-dimensional porous titanium dioxide foam. The adipose stem cells grown on the titanium dioxide foam, then differentiate into osteoblasts cells and adipocytes cells.

The study researched the different porosity titanium dioxide foam for the effect of the differentiation of adipose stem cells, used the X-ray diffraction(X-ray diffraction, XRD), scanning electron microscope (SEM) to analysis the crystal structure and surface morphology of the titanium dioxide foam. The XRD results show the sample did not produce other compounds. The SEM result show the holes and the porosity of titanium dioxide foam increase with the volume of sodium chloride.

In the part of the culture of adipose stem cell, Fluorescein Diacetate (FDA) fluorescence image could observed the adipose stem cells attached on the titanium dioxide foam, and the multifunctional microplate analyzer calculated the cell count had growth trend, which means that titanium dioxide for adipose stem cells is non-toxic.

In the part of the differentiation of adipose stem cell, for the adipose stem cells differentiate into bone cells, quantitative real-time polymerase chain reaction (qPCR) measured the gene expression found in the titanium dioxide foam had poorly differentiated effects compared with the well plate. For the effect of adipose stem cells differentiate into adipose cells on titanium dioxide foam, the adipose cells gene expression on titanium dioxide foam are significantly better than the adipose cells gene expression on well plate. Also the oil droplets staining experiment also confirmed the adipose cells were generated on the titanium dioxide foam and on the well plate.

This experiment could be learned that the effect of adipose stem cells differentiate into bone cells on titanium dioxide foam is poor, however the effect of adipose stem cells differentiate into adipose cells on titanium dioxide foam is better than on the well plate, this meant that the titanium dioxide foam suit adipose stem cells to differentiate into adipose cells.