用于肿瘤逆转的新型可注射生物活性水凝胶材料的研究

发布时间：2018-11-17 08:27

【摘要】：胚胎组织的微环境可通过表遗传学机制使肿瘤细胞逆向转化为表型正常的细胞，这一过程主要是通过抑制肿瘤细胞中不受调控的nodal信号蛋白的过度表达实现的。针对这样的发现，有研究者提出在体外模拟该系统用于肿瘤治疗的研究设想。为此，本研究采用胚胎细胞外基质的主要成分透明质酸为基本材料，将透明质酸和IV型胶原中的活性肽段通过化学交联的方法设计成可注射的水凝胶，来模拟胚胎发育的物理微环境，并将nodal受体cripto-1的封闭抗体接枝到水凝胶的骨架上，来模拟胚胎发育中逆转肿瘤的生物学微环境。通过对水凝胶材料流变学、孔隙率、显微形貌的研究及肿瘤细胞三维培养后显微形貌的观察，该水凝胶系统能够作为体外肿瘤逆转研究的理想支架材料。我们选用人乳腺癌细胞系MCF-7细胞系作为快速增殖而不具有侵袭性代表，MDA-MB-231乳腺肿瘤细胞系作为侵袭和转移性肿瘤细胞的代表。体外检测该水凝胶系统对乳腺癌细胞恶性表型的影响。体外实验结果表明，水凝胶系统能有效逆转肿瘤细胞的恶性表型，促进线粒体膜电位下降、细胞凋亡，降低细胞的侵袭性。利用小动物活体成像技术对于凝胶的体内降解进行了研究，表明该凝胶在体内的降解持续10天。分别利用黑色素肿瘤细胞B16和MDA-MB-231制备了荷瘤鼠模型，并对水凝胶系用于荷瘤鼠肿瘤模型肿瘤逆转治疗的有效性进行研究。液态凝胶可以注射到肿瘤部位，并在瘤体内固化形成不溶的胶体，局部形成逆转肿瘤的微环境。研究结果表明：该水凝胶系统能显著减小MDA-MB-231肿瘤的体积，，并在注射后38天，实验组部分小鼠瘤体消失；并有效抑制恶性程度高的B16肿瘤的生长。本课题研制出一种新型的生物活性水凝胶材料用于肿瘤的逆向转化治疗，为肿瘤的治疗开辟了新的途径。
[Abstract]:The microenvironment of embryonic tissue can reverse transform tumor cells into normal phenotypic cells by epigenetic mechanism, which is mainly achieved by inhibiting the overexpression of uncontrolled nodal signal proteins in tumor cells. In response to these findings, some researchers proposed to simulate the system in vitro for tumor therapy. Therefore, hyaluronic acid, the main component of extracellular matrix of embryo, was used as the basic material. The active peptides of hyaluronic acid and IV collagen were chemically crosslinked to form injectable hydrogels. To simulate the physical microenvironment of embryonic development and graft the blocking antibody of nodal receptor cripto-1 onto the framework of hydrogel to simulate the biological microenvironment of tumor during embryonic development. The hydrogel system can be used as an ideal scaffold for tumor reversal in vitro by studying the rheology, porosity and morphology of hydrogel materials and observing the microscopic morphology of tumor cells after three-dimensional culture. The human breast cancer cell line MCF-7 cell line was chosen as the representative of rapid proliferation and not invasive, while the MDA-MB-231 breast cancer cell line was used as the representative of invasive and metastatic tumor cells. The effect of the hydrogel system on the malignant phenotype of breast cancer cells was detected in vitro. The results showed that the hydrogel system could effectively reverse the malignant phenotype of tumor cells, promote the decrease of mitochondrial membrane potential, apoptosis and decrease the invasiveness of tumor cells. The degradation of the gel in vivo was studied by using in vivo imaging of small animals, which showed that the degradation of the gel lasted for 10 days. The tumor-bearing mouse models were established by using melanoma cells B16 and MDA-MB-231, respectively, and the effectiveness of hydrogel system for tumor reversal therapy in tumor-bearing mice was studied. Liquid gel can be injected into the tumor site and solidified in the tumor body to form an insoluble colloid. The results showed that the hydrogel system could significantly reduce the volume of MDA-MB-231 tumor, and at 38 days after injection, the tumor of some mice in the experimental group disappeared, and the growth of B16 tumor with high malignancy was effectively inhibited. In this paper, a new bioactive hydrogel material was developed for reverse transformation therapy of tumor, which opened up a new way for tumor treatment.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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