Safety and Efficacy Study Using Gene Therapy for Critical Limb Ischemia (NL003-CLI-III-1)

Inclusion Criteria: * 1\. Age 20 and 80 (when signing informed consent), both male and female; 2\. Patients diagnosed with lower limb arterial ischemic disease based on DSA or CTA and combined with their medical history and clinical manifestations and Rutherford grade 4 (resting pain) must meet the following criteria simultaneously (if both limbs of the subject have lower limb arterial ischemic disease, the researcher shall choose one limb for the study).Resting ankle systolic pressure (dorsal foot artery or posterior tibial artery) ≤70mmHg or ABI≤0.5 or TcPO2 \< 30mmHg;In the first 3 months after randomized inclusion, DSA or CTA confirmed severe stenosis (≥70%) or occlusion of superficial femoral artery or popliteal artery or inferior knee artery. 3\. Chronic lower limb arterial ischemia combined with resting pain met the following requirements: resting pain lasted for more than 2 weeks when the informed consent was signed; 4\. Agreed to use the basic treatment drugs as required during the trial, and recorded the daily record of the subjects in a timely and complete manner. The compliance of the basic treatment drugs and the subjects' diary filling during the screening period was 70%. 5\. Agree to use appropriate contraceptive measures during the experiment;Female subjects of reproductive age, blood pregnancy test negative; 6\. Signed informed consent Exclusion Criteria: * 1\. Patients with acute lower limb ischemia or acute exacerbation of chronic lower li…