利用奈米碳管之光熱特性促進腫瘤細胞衰亡

Abstract

在眾多的癌症療法中，將奈米粒子輸入癌細胞內，自癌細胞內部進行物理或化學的治療，由於這是在微觀層級以下的療法，因此其效率及潛力具有相當的研究價值。目前癌症治療方式有很多種，最常被醫界認同使用的癌症治療方式可分成四種，即外科手術療法、放射療法、化學療法及免疫(基因)療法，這些療法皆有一定的效用，但也都有一定的限制與瓶頸。因此考慮利用其他的方式(如光、熱等)進行治療為目前癌症治療研究的方向之一。由於奈米碳管具有吸收近紅外光，進而將近紅外光轉為熱能的特性，因此本研究即是將奈米碳管利用腫瘤細胞相應之配體修飾後，與腫瘤細胞共同培養，再以近紅外光照射，利用奈米碳管作為能量轉換的媒介，轉換光能成為熱能，利用過量的熱能使細胞不堪負荷促使細胞的衰亡。 本研究選用神經母細胞瘤細胞stNB-V1，在其表面上有大量的disialoganglioside(GD2)抗原。另外選用無GD2表達之NIH 3T3細胞、BHK-21細胞以及PC-12細胞作為對照組。實驗結果顯示，若碳管上修飾細胞相對應之GD2單株抗體再和上述細胞分別共同培養，在其餘條件皆相同的狀況下，表現有GD2之stNB-V1細胞經由雷射照射後，在雷射照射區域呈現死亡的狀態，而無抗體相對應之對照組細胞則依然存活。由此可見碳管修飾抗體能針對具有標的之腫瘤細胞有顯著的效果，而不會對非標的之細胞造成損害。本研究除了結合奈米碳管、抗體、腫瘤細胞與雷射進行光熱療法實驗外，亦對奈米碳管本身的特性作了部份分析，如碳管酸化前後大小、型態、官能基以及在液體中的分散性之比較。另外也比較了不同濃度的奈米碳管吸收雷射光後對整體溫度的影響，以及觀察碳管在細胞內的狀態。從各種角度反覆驗證與比較此概念之理論與實驗結果之間的異同。

Delivering nanoparticles into cancer cells to proceed physical or chemical therapy is an emerging method in comparison with current cancer therapy methods. In general, strategies used to treat cancer cells can be classified into surgery, radiation, immunotherapy and chemotherapy, which all have their limitation. Therefore, development of innovative treatments for destroying cancer cells remains an important research topic. Because carbon nanotubes (CNTs) can absorb near-infrared light and transform it to heat, we in this study employed CNTs modified with antibody to specifically bind on tumor cells, and then irradiated with 808 nm near-infrared (NIR) laser which can result in malignant cells underwent necrosis due to the existence of carbon nanotubes internalized in cytosol. Brain tumor stNB-V1 cell line (derived from neuroblastoma) was chosen in this research. On the surface of neuroblastoma cells, there are plenty of disialoganglioside (GD2) glycolipid antigens.. For control groups without GD2 antigen, we selected NIH 3T3, BHK-21 and PC-12 cells. Our results showed that CNTs modified with GD2 monoclonal antibody can be massively internalized into stNB-V1 cells, while this case was not observed for the cells from the control group. After NIR laser irradiation, only stNB-V1 cells in the region exposed to the laser beam were killed. In this research, not only combing carbon nanotube, antibody, tumor cell, and NIR laser to perform thermoablative treatment, but also analyzing the characteristics of carbon nanotubes. Detailed physicochemical analysis of CNTs in size, shape, functionalization, and suspension in different solvents was done prior to the cell experiments. In addition, bulk water temperature profiles in the presence of various CNT concentrations after NIR laser irradiation were measured.