The Safety and Tolerability of XS411CN Injection in Treatment of Primary Parkinson's Disease

Inclusion Criteria: 1. Male or female, aged between 50 and 75 years old; 2. Diagnosed as 'clinically established PD' consistent with MDS clinical Diagnostic Criteria for Parkinson's disease, 3. A minimum of 5 years since diagnosis; 4. Hoehn- Yahr score during the off-time is 3 to 4; 5. The subjects with an average of at least 2.5 hours of "off time" per day; 6. Stable anti-PD therapy for at least 1 month before screening; 7. Anti-PD treatment was once effective, but the efficacy has declined significantly or drug-induced motor complications have occurred, affecting the quality of life; 8. Positive levodopa challenge test (MDS-UPDRS-III score improvement from off- state to on- state \> 30%); 9. At least three months before the first administration, the subject should have completed all vaccinations as recommended by local authorities; 10. The results of complete blood count meet the following conditions: ANC ≥ 2.0×109 /L, WBC ≥ 4.0×109 /L, PLT≥ 100×109 /L, HGB ≥ 10g/dL 11. The patient or his/her legal guardian agree to accept the study and signed the informed consent form in writing. Exclusion Criteria: 1. Parkinsonian syndrome or secondary Parkinson's disease (Atypical Parkinson's syndrome (Parkinson's plus syndrome, secondary Parkinson's syndrome, hereditary degenerative Parkinson's syndrome); 2. Patients are in advanced stages of Parkinson's disease and are experiencing severe, disabling peak-dose dyskinesia or biphasic dyskinesia and/or unpredictable or widely fluctuating symptoms; 3. Severe cognitive impairment (MMSE\<24, poor compliance due to dementia, inability to accurately record diaries, and/or inability to sign informed consent; 4. Those with a history of severe mental illness, or those with severe suicidal tendencies as measured by the Columbia-Suicide Severity Rating Scale (C-SSRS), or those with suicidal ideation in the past 12 months, or those who have attempted suicide in the past 5 years; 5. Patients with severe brain atrophy, space-occupying lesions, hydrocephalus, cerebral vascular malformations as indicated by head CT/MRI, and those with structural abnormalities that may affect transplantation or increase surgical risks as determined by the investigators; 6. Currently with active internal bleeding; or arterial puncture at a site that is difficult to stop bleeding within 1 week before screening; or gastrointestinal or urinary bleeding within 3 weeks before screening; 7. History of striatal or extrapyramidal surgery, including but not limited to deep brain stimulation (DBS) surgery and globus pallidus lesion; 8. Coagulation abnormalities; 9. Abnormal liver and kidney function laboratory tests during the screening period; 10. The patient is currently receiving or has previously received the following treatments: * Use of benzodiazepines at a dose level equal to or higher than the recommended dose in Package Insert for more than 4 weeks cumulatively since one month before enrollment, immunosuppressants (except for the immunosuppressants to be used in this study), or antipsychotics within 3 months before treatment; * Use of botulinum toxin, phenol, subarachnoid baclofen injection, or interventional treatment for dystonia or spasticity within 6 months before treatment; * Have a history of epilepsy or use anti-epileptic drugs for prevention; * Received cell therapy within 3 months before screening; 11. Contraindications to general anesthesia or stereotactic surgery (such as sleep apnea, chronic obstructive pulmonary disease, etc.), MRI or PET examinations; 12. Those with the following abnormalities in the past or detected (if any of the following is met, they will be excluded): * Evidence of congestive heart failure or history of end-stage cardiovascular disease; * Severe arrhythmias and poorly controlled arrhythmias; * Clinically significant electrocardiogram abnormalities during the screening or baseline period; * History of unstable angina or acute myocardial infarction within the past 3 months; * Diabetic patients with poor glycemic control; * Hypertensive patients with poorly controlled blood pressure; 13. Patients with active infection during the screening period (except mild local skin infection) that need antibiotic, antifungal, or antiviral treatment but infection is still not under control; 14. The presence of severe lung diseases during the screening period; 15. Patients with uncontrolled autoimmune diseases; 16. During the screening period, patients have severe arthritis, limp, severe sequelae of stroke, severe osteoporosis, or history of severe trauma within 1 month, etc., which the investigators assess may affect the evaluations; 17. Any history of malignancy, excluding cured basal cell carcinoma and/or squamous cell carcinoma of the skin, carcinoma in situ of the cervix, or ductal carcinoma of the breast; 18. Serious infectious diseases; 19. Pregnant or lactating women, women who plan to become pregnant during the study and within 6 months after the end of the study, or women who are unwilling to use effective contraceptive measures; 20. Patients who have participated in other clinical studies of drugs or medical devices within 3 months before treatment; 21. Have a long history of alcoholism or drug abuse; 22. Patients with a history of severe allergies or allergies to investigational drugs and immunosuppressants; 23. Any other conditions that the investigator considers unsuitable for participation in the study. 24. Severe depression 25. Hallucinations, and hallucinations still exist after optimizing Parkinson's medications 26. Patients have undergone MRI-guided focused ultrasound thalamotomy 27. Used immunosuppressants within 3 months, except for the immunosuppressants to be used in this study