苯丙酮尿症（PKU）是一种常见的氨基酸代谢缺陷单基因遗传性疾病，导致患者智力发育不全，目前治疗效果不理想，亟待发展新的治疗手段。CRISPR-Cas9基因编辑技术可以从源头基因组对致病基因进行修改，达到从根本上治愈疾病的目的，为PKU的治疗带来新希望。我们在前期研究中，发展了一种新型靶向非病毒基因递送系统，可高效转染超大质粒，实现体内基因编辑，相关结果发表于ACS Nano（2017, 11: 95-111）。本项目将在前期研究基础上，设计并构建新型肝靶向非病毒基因载体，可高效转染CRISPR-Cas9基因编辑系统，将表达苯丙氨酸羟化酶（PAH）的组件插入基因组安全位点，实现体内高效基因编辑，达到长期、稳定、高效表达PAH并治疗PKU的目的，并深入研究其作用机制。本项目的开展将为发展肝靶向基因递送系统提供新思路，也将为CRISPR-Cas9基因编辑技术应用于疾病治疗提供理论依据和研究基础。

Phenylketonuria (PKU) is a common single gene inheritance disease of amino acids metabolism deficiency, and will result in mental hypoplasis of patients. Therapeutic effect of PKU is unsatisfactory, so it is still urgent to develop new treatments. CRISPR-Cas9 gene editing technology can modify the virulence gene in the genome to cure the disease, which will bring a new hope for the treatment of PKU. In our previous work, we developed a novel targeting non-viral gene delivery system, which could effectively transfect of large plasmid to achieve in vivo gene editing. The results of our previous work had been published in ACS Nano (2017, 11: 95-111). The present project is proposed on the basis of our previous studies. In this work, we will design and synthesize a novel liver-targeting non-viral gene vector. The prepared gene vector can effectively transfect CRISPR-Cas9 gene editing system to insert the expression component of phenylalanine hydroxylase (PAH) into the safe harbor in genome, which can achieve effective gene editing in vivo and can long-term, stable and effective expression of PAH to cure PKU. We will investigate the effects and mechanism of the novel liver-targeting non-viral gene vector and CRISPR-Cas9-mediated PKU treatment. Execution of this study will bring new idea for the development of liver-targeting gene delivery system, and provide theoretical and research basis for the further clinical application of CRISPR-Cas9 gene editing technology in disease treatment.