基于肿瘤热疗的双靶向基因载体构建及其前列腺癌治疗的研究

Preparation of functional biomaterials used for bioinstrumentation and medical treatment by means of multi-dimensional printing technique is one of research hotspots in printing industry. This project focuses on the fabrication of dual-target gene-delivering nanosystem encapsulating ferroferric oxide superparamagnetic nanoparticles (Fe3O4 NPs), which could penetrate the capsula prostatica with effects of passive target and warming-up in the magnetic field, as well as modification with AS1411 molecule on surfaces of biodegradable cationic liposome. Moreover, the gene nanovector could effectively load the wild-type constructed p53 plasmids. Ultimately, the transfection efficacy of p53 gene is evaluated on cellular level in vitro. Meanwhile, the targeting ability of dual-target cationic liposome on prostatic carcinoma under the magnetic field is thoroughly assessed through establishing models of prostatic carcinoma spheroid and prostate cancer using orthotopic implantation in nude mice. The research results of the project will lay the basis for further work, which is that novel nanosensor based on dual-target cationic liposome is printed into three-dimensional hydrogel scaffold embedded in human body for early diagnosis of prostatic cancer.

通过多维打印技术，制备可用于生物检测、医学治疗的组织工程支架材料，目前已成为印刷领域的热门研究之一。本项目针对前列腺癌存在检测难、治愈难的问题，以具有生物可降解性的阳离子脂质体为基材，利用磁场作用下超顺磁Fe3O4纳米颗粒具有可透过前列腺包膜以及被动靶向、升温的特点，制备内含Fe3O4纳米颗粒、表面修饰识别前列腺特异性膜抗原的AS1411分子的双靶向阳离子脂质体，该基因载体可有效负载EGFP-p53质粒。通过检测p53基因在细胞水平上转染效果，同时建立三维前列腺癌细胞球模型及裸鼠原位前列腺癌模型，综合评价双靶向基因载体在磁场存在条件下靶向识别前列腺癌细胞的能力，有效输运p53基因而治疗前列腺癌的效果。以上工作为进一步采用三维打印技术，将基于双靶向阳离子脂质体开发的新型纳米传感器植入三维水凝胶支架，从而植入人体用于前列腺癌的早期诊断，奠定一定工作基础。

本项目试图制备高基因递送效率的基因载体，并评价其输运p53基因而治疗前列腺癌的效果。.项目主要研究内容有三。一是设计、制备胞内基因释放效率高的层层组装基因载体；二是选择具有光热效应的金属纳米颗粒，构建具有热疗作用的靶向基因载体。. 重要结构及其科学意义如下：.1. 将pH敏感分子PAH-Cit引入基因载体，通过简单的层层组装法得到的PEI/PAH-Cit/Au NPs-CS，不仅生物相容性好，而且可有效抑制前列腺癌细胞PC-3的生长，并通过线粒体介导凋亡通路诱导PC-3细胞死亡。.2. 以金纳米笼（AuNCs）为核构建基因载体，克服了单一依靠基因治疗的缺点，使基因载体同时具有热疗作用，有利于增强基因载体诱导前列腺癌细胞死亡的效果。.3. 将阳离子脂质体与磁性纳米颗粒结合，得到一种具有被动靶向和热疗效应的基因载体，对于提高基因治疗前列腺癌的效果具有一定的价值。