開發奈米鑽石連結紫杉醇作為藥物運送與癌症治療

Abstract

利用奈米物質攜帶抗癌藥物，提供一個嶄新的機會作為癌症的治療。在本篇研究中，我們利用一種由碳所組成的奈米材料，稱作奈米鑽石，以共價鍵的方式連結紫杉醇，作為藥物的運送和癌症的治療。透過一連串化學修飾的合成方法，將紫杉醇鍵結到奈米鑽石的表面。在濃度0.1-50 μg/mL的奈米鑽石-紫杉醇處理A549人類肺癌細胞48小時之後，明顯降低癌細胞的存活率，然而單獨處理奈米鑽石或是經強鹼處理過後的奈米鑽石-紫杉醇，並不會誘發A549肺癌細胞的死亡。由共軛焦顯微鏡觀察，我們發現奈米鑽石-紫杉醇會進入A549肺癌細胞，並且位在細胞質及微小管。奈米鑽石-紫杉醇仍然具有紫杉醇的抗癌活性，會造成細胞的有絲分裂停止和細胞凋亡，並且抑制CDC2、磷酸化CDC2及cyclin B1蛋白的表達。此外，在異體移植人類肺癌細胞到先天免疫不全的老鼠之動物實驗中，奈米鑽石-紫杉醇會抑制老鼠體內腫瘤的形成。再者，我們也發現奈米鑽石-紫杉醇在其他種類的人類癌細胞，包括大腸癌細胞(ROK和HCT116)和膀胱癌細胞(BFTC 905)也會誘發細胞毒性和細胞凋亡，並且造成caspase-3蛋白的活化及PARP蛋白被切割。綜合以上結果，我們已經開發出一種功能性之共價鍵結奈米鑽石-紫杉醇，具有促使有絲分裂停止、誘發細胞凋亡及抑制腫瘤形成的抗癌活性。

Nanoparticle-conjugated anticancer drugs provide novel opportunities for cancer therapy. In this study, we evaluated nanodiamond (ND), a carbon nanomaterial, to covalently bind paclitaxel for drug delivery and cancer therapy. Paclitaxel was bound to the ND’s surface through a succession of chemical modification. Treatment with 0.1-50 μg/mL ND-paclitaxel for 48h significantly reduced the cell viability in A549 human lung cancer cells. However, ND alone or denatured ND-paclitaxel (after treatment with strong alkaline solution, 1M NaOH) did not induce the damage effects on A549 cells. The ND-paclitaxel was taken into cell and located in the microtubules and cytoplasm of A549 cells observed by confocal microscopy. Moreover, ND-paclitaxel still reserves the anticancer activity of paclitaxel. ND-paclitaxel was attributed both mitotic blockage and apoptotic induction in cancer cells. The protein levels of CDC2, phosphorylated CDC2, and cyclin B1 were decreased by treatment with ND-paclitaxel. Besides, ND-paclitaxel inhibited the tumorigenesis of xenograft human lung tumor in SCID mice. Moreover, we also found ND-paclitaxel was significantly induced cytotoxicity and apoptosis in other cancer cells including colon cancer cells (RKO and HCT116) and bladder cancer cells (BFTC 905). ND-paclitaxel induced the caspase-3 activation and the protein cleavage of PARP. In summary, we have developed a functional covalent ND-paclitaxel, which still preserves its anticancer activities on the mitotic blockage, apoptosis induction and anti-tumorigenesis.