發(fā)布時間：2018-03-31 16:37

  本文選題：介孔二氧化硅　切入點：金屬配合物　出處：《暨南大學(xué)》2016年博士論文

【摘要】：惡性腫瘤嚴重危害人類健康,腫瘤治療已經(jīng)成為當(dāng)前醫(yī)學(xué)研究領(lǐng)域所面臨的一個重大挑戰(zhàn)。在目前的治療中,化療在腫瘤的綜合治療中占主導(dǎo)地位,但是化療藥物在腫瘤治療過程中所引起的全身性毒副作用嚴重限制了其臨床使用。近年來,納米技術(shù)的出現(xiàn)為抗腫瘤藥物設(shè)計提供了新思路。納米技術(shù)融合生物學(xué)和納米工程學(xué),在腫瘤成像、腫瘤診斷和腫瘤靶向治療等方面展現(xiàn)出了廣闊的應(yīng)用前景。納米體系通過靶向性修飾,能將藥物有針對性地遞送到病變組織,提高治療效果并減少對正常組織的毒副作用。目前,已有大量的納米材料作為納米載藥體系而被廣泛關(guān)注。其中,介孔二氧化硅納米材料由于其具有明顯的優(yōu)勢而被作為一種理想的載藥體系。在本課題中,我們通過對該納米材料進行功能化修飾,并作為化療藥物的傳遞系統(tǒng),實現(xiàn)其在腫瘤治療中的應(yīng)用。具體研究結(jié)果如下:1、盡管金屬配合物表現(xiàn)出潛在的抗腫瘤活性,并表現(xiàn)出巨大的前景,但是它們?nèi)匀淮嬖诓豢杀苊獾募毎拘�、細胞攝取率低以及不具有選擇性等缺點。為了解決金屬配合物的這一難題,在本課題中,我們設(shè)計合成出一種RGD多肽修飾的靶向二氧化硅納米體系作為該類金屬配合物的傳遞系統(tǒng),實現(xiàn)了藥物對腫瘤細胞和正常細胞之間的選擇性,從而提高了藥物抗腫瘤活性,并降低其毒副作用。RGD的修飾能大大提高該納米體系通過整合素介導(dǎo)細胞吸收,從而實現(xiàn)藥物對腫瘤細胞的靶向性。此外,該靶向納米載藥體系主要是激活了腫瘤細胞的死亡受體通路,進一步誘導(dǎo)ROS在細胞內(nèi)的累積,從而引起DNA損傷,激活了p53、AKT以及MAPKs信號通路而誘導(dǎo)細胞凋亡,闡明了該納米體系的抗腫瘤分子機制。2、腫瘤血管為腫瘤微環(huán)境提供必要的養(yǎng)料和氧氣,對腫瘤的發(fā)生、發(fā)展和代謝起了至關(guān)重要的作用。因此針對血管形成的某些因子及其關(guān)鍵步驟進行干預(yù)可有望切斷腫瘤血供及其轉(zhuǎn)移途徑,對腫瘤的治療和防止腫瘤向遠處轉(zhuǎn)移有重要意義。因此,在該部分實驗中,我們基于腫瘤細胞與血管內(nèi)皮細胞的生物化學(xué)相似性,設(shè)計了雙重靶向腫瘤與血管細胞的納米體系,通過抑制血管細胞的生長來切斷腫瘤細胞增殖所需營養(yǎng),同時直接誘導(dǎo)腫瘤細胞凋亡,最終實現(xiàn)抑制腫瘤與血管生成。實驗結(jié)果發(fā)現(xiàn),該雙靶向納米體系在體內(nèi)外雙腫瘤模型和細胞共培養(yǎng)中,對腫瘤組織和腫瘤細胞表現(xiàn)出很高的選擇性,并能有效的誘導(dǎo)腫瘤細胞凋亡,而減少對正常細胞的毒性。此外該納米體系能通過激活p53信號通路誘導(dǎo)腫瘤細胞凋亡,從而抑制腫瘤生長和血管生成。3、目前,腫瘤的治療手段仍然以手術(shù)切除、放射性治療以及化學(xué)藥物治療為主。放射線雖然對腫瘤細胞具有較直接的殺死和抑制效果,但是由于腫瘤處于低氧環(huán)境中,使得單獨的放療無法徹底根除腫瘤細胞,反而使腫瘤對x射線產(chǎn)生耐受而不敏感。因此,設(shè)計合成一種高效低毒的放療增敏劑并發(fā)揮其與放療的協(xié)同作用具有重要意義。在該部分研究中,我們將二氧化硅納米材料負載一種含硒氨基酸,同時將細胞穿膜肽和轉(zhuǎn)鐵蛋白共價連接到高分子聚合物plga上,并將其對二氧化硅納米載藥體系進行包裹,得到一種多功能納米載藥體系,實現(xiàn)對放療的增敏效果。實驗結(jié)果發(fā)現(xiàn),該納米體系能有效的協(xié)同放療增強x射線誘導(dǎo)的腫瘤細胞凋亡,并且主要是激活細胞內(nèi)死亡受體介導(dǎo)的信號通路。此外,在x射線的照射下,sec@msns-tf/tat能促進細胞內(nèi)ros的大量累積,從而激活下游akt和mapks信號通路,并引起細胞內(nèi)dna損傷介導(dǎo)的p53信號通路的激活,同時能抑制細胞的自我損傷修復(fù)功能,最終誘導(dǎo)細胞凋亡。sec@msns-tf/tat同能有效的通過激活體內(nèi)腫瘤組織中p53介導(dǎo)的細胞凋亡,從而抑制小鼠體內(nèi)荷瘤生長,且在有效抗腫瘤濃度下對小鼠無明顯毒性,說明所設(shè)計合成的多功能納米體系sec@msns-tf/tat能作為一種高效低毒的放療增敏劑實現(xiàn)體內(nèi)外腫瘤同步放化療的應(yīng)用。4、由于納米材料特殊的尺寸和形貌,使得它相比于宏觀尺度的材料具有很多特殊的效應(yīng)(小尺寸效應(yīng)、表面效應(yīng)、宏觀量子隧道效應(yīng)等),并賦予了納米材料廣泛的應(yīng)用前景。因此,在本課題研究中,我們通過對堿性催化劑類型和濃度的改變合成出不同尺寸大小的介孔二氧化硅納米粒子,并研究了三種不同尺寸(20nm、40nm和80nm)納米載藥體系對腦膠質(zhì)瘤細胞的吸收、停留以及滲透進入血腦屏障能力的影響。實驗結(jié)果發(fā)現(xiàn),這三種不同尺寸的靶向納米體系dox@msns能顯著提高單獨dox誘導(dǎo)腦膠質(zhì)瘤細胞產(chǎn)生過量的ros,從而增強其誘導(dǎo)腫瘤細胞凋亡的程度,提高了dox的抗腫瘤效果,同時尺寸為40nm的納米體系表現(xiàn)出更優(yōu)的效果。此外,這三種不同尺寸靶向納米藥物能有效地穿透血腦屏障,并被腦膠質(zhì)瘤細胞吸收,提高單獨dox的抗腫瘤效果。同時能有效地摧毀腦膠質(zhì)瘤細胞的血管擬態(tài)生成,從而增強其抗腫瘤效果。該納米藥物對腫瘤球生長是尺寸依賴性的,DOX@MSNs納米體系對腫瘤球的滲透作用明顯強于單獨DOX,從而增強其對腫瘤球生長的抑制作用。綜上所述,介孔二氧化硅納米材料作為一種理想的化學(xué)藥物載體,通過靶向修飾能有效的提高化療藥物的抗腫瘤活性以及對腫瘤細胞和正常細胞的選擇性,進而減少藥物的毒副作用。這種多功能納米體系能同時實現(xiàn)對抗體內(nèi)外腫瘤生長和血管生成,并能作為一種高效低毒的放療增敏劑協(xié)同X射線提高抗腫瘤效果。并且,在本課題的研究中,我們也對這類靶向納米體系的體內(nèi)外抗腫瘤作用機制進行了清楚的闡述。因此,我們認為:本課題的工作為進一步開發(fā)靶點清楚、作用機制明確的新型靶向納米藥物或先導(dǎo)物在腫瘤診療中的應(yīng)用提供科學(xué)依據(jù)。
[Abstract]:Malignant tumor serious harm to human health, cancer treatment has become a major challenge in the field of Medical Research Institute. In the present treatment, chemotherapy is dominant in tumor therapy, but the side-effect of chemotherapy caused by tumor in the treatment of severe systemic limiting the clinical use of in recent years. Here, the emergence of Nanotechnology provides new ideas for anticancer drug design. Nano biology and engineering integration of nanotechnology, in tumor imaging, tumor diagnosis and tumor targeting therapy has shown a broad application prospect. Nanoparticles modified by target, can be targeted drug delivery to disease the organization, improve the therapeutic effect and reduce the side effects on normal tissues. At present, there are a large number of nano materials as nano drug delivery system has been widely concerned. Among them, Kong Eryang referred to silicon Nano materials because of its obvious advantages have been used as an ideal drug loading system. In this paper, we through functionalization of the nano materials, and as a drug delivery system for its application in the treatment of tumor. The results are as follows: 1, although the performance of metal complexes the potential antitumor activity, and shows great prospect, but they still have the inevitable cytotoxicity, cellular uptake rate is low and is not selective and other shortcomings. In order to solve this problem with metal objects, in this article, we designed and synthesized a RGD polypeptide modified silica nanoparticles targeting transfer system as a system of this kind of metal complexes, the selective drugs between tumor cells and normal cells, thus improving the drug antitumor activity, and reduce the side effects of.RGD Modification can greatly improve the nano system through integrin mediated cell absorption, so as to realize the drug targeting of tumor cells. In addition, the targeted nano drug delivery system is the activation of the death receptor pathway of tumor cells and further induce ROS accumulation in cells, the damage caused by DNA, the activation of p53. AKT and MAPKs signaling pathway and induce cell apoptosis, and discusses the system of anti nano molecular mechanism of tumor.2, tumor vascular tumor microenvironment provide the necessary nutrients and oxygen, and the occurrence of cancer, development and metabolism played a crucial role. Therefore some angiogenic factor and key steps of intervention is expected to cut off the blood supply of the tumor and its metastasis pathway, the treatment of tumors and to prevent tumor metastasis has important significance. Therefore, in this part of the experiment, we based on tumor cells and endothelial cells Biochemistry cell similarity design double targeting tumor cells and blood vessels in the nano system, by inhibiting the growth of vascular cell proliferation of tumor cells to cut off the needed nutrients, and directly induce apoptosis of tumor cell, and ultimately inhibit tumor and angiogenesis. The experimental results showed that the dual targeting nanoparticles in vivo double tumor model and cell culture, high selectivity of tumor tissues and cells from the tumor, and can effectively induce the apoptosis of tumor cells, and reduce the toxicity to normal cells. In addition the nano system can induce the apoptosis of tumor cells to activate the p53 pathway to inhibit tumor growth and angiogenesis of.3, at present the treatment of tumor, still with surgical resection, radiotherapy and chemotherapy. Although radiation has a direct effect on killing and inhibiting tumor cells, but Is due to the tumor in the hypoxic environment, so that the separate radiotherapy is unable to completely eradicate tumor cells, but the tumor of X ray resistant and not sensitive. Therefore, has important significance to design and synthesis of a synergistic effect of radiotherapy with high efficiency and low toxicity sensitizer and play with radiotherapy. In this study, we will silica nano material load for selenium containing amino acid, while the cell penetrating peptide and transferrin covalently attached to the polymer PLGA, the silica nanoparticles delivery system package system of a multifunctional nano drug carrier, to achieve the effect of increasing sensitivity to radiotherapy. The experimental results showed that the nano system can effectively the synergistic enhancement of tumor cell apoptosis radiotherapy induced by X irradiation, and mainly activate intracellular signaling pathway mediated by death receptor. In addition, the X - ray irradiation, sec@ msns-tf/tat To promote the accumulation of intracellular ROS, Akt and MAPKs to activate downstream signaling pathways, and activate intracellular p53 signaling mediated DNA damage, and can inhibit the cell self repair function, ultimately inducing apoptosis of.Sec@msns-tf/tat apoptosis and effectively through activation of in vivo tumor tissues mediated by p53. In order to inhibit tumor growth in mice, and the effective anti-tumor concentration in mice without obvious toxicity. The design of multifunctional nano system sec@msns-tf/tat synthesis can be used as a.4 synchronous radiation sensitizer to achieve high efficiency and low toxicity in vivo tumor chemotherapy, due to the size and morphology of nano materials, making it compared to the macro scale material has many special effects (small size effect, surface effect, quantum tunneling effect and so on), and given the nano materials should be widely With prospects. Therefore, in this research, we based on the alkaline catalyst type and the change of the concentration of the synthesis of mesoporous silica nanoparticles of different sizes, and studied three different sizes (20nm, 40nm and 80nm) nanoparticles delivery system on glioma cell absorption, and penetrate into the blood effect of residence brain barrier ability. The experimental results showed that the three different sizes of targeted nano dox@msns system can significantly improve the DOX overproduction of ROS glioma cells induced by, so as to enhance the induction of tumor cell apoptosis degree, improve the antitumor effect of DOX, while the size of 40nm nanoparticles showed better the effect. In addition, the three different sizes of targeted nano drug can effectively penetrate the blood-brain barrier and absorbed glioma cells, enhance the antitumor effect of DOX alone and can effectively destroy the brain. Vasculogenic glioma cells, thereby enhancing the anti-tumor effect. The nano drugs on the growth of tumor sphere is size dependent. The penetration effect of nano DOX@MSNs system on tumor sphere was stronger than DOX alone, thereby enhancing its inhibitory effect on tumor growth of the ball. To sum up, mesoporous silica nanoparticles as an ideal chemical drug carrier, can enhance the antitumor activity of chemotherapeutic drugs is effective and selective for tumor cells and normal cells to modified by target, thereby reducing the side effects of drugs. The multifunctional nano system can be generated at the same time on the growth and vascular tumors and antibody, as an efficient radiotherapy low toxicity sensitizing agents improve the anti-tumor effect of collaborative X ray. Also, in this research, we also carry on this kind of targeting nanoparticles in vitro and in vivo antitumor mechanism Therefore, we believe that our work will provide a scientific basis for further development of new targeted nano drugs or precursors with clear targets and mechanisms in the diagnosis and treatment of tumors.

【學(xué)位授予單位】：暨南大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：R730
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本文編號：1691556