Study on Safety and Efficacy of UCB-MNCs for Chronic Radiation Enteritis

Inclusion Criteria: 1. Aged 18-75 years, with no restriction on gender; 2. History of pelvic and abdominal radiotherapy; 3. Patients diagnosed with chronic radiation-induced intestinal injury (CRII) via colonoscopy and pathological examination (≥3 months after the end of radiotherapy); 4. Diagnosed with grade 2-3 radiation-induced intestinal injury based on the clinical symptom assessment (RTOG classification) in Expert Consensus on Integrated Traditional Chinese and Western Medicine Diagnosis and Treatment of Radiation-Induced Intestinal Injury in China; 5. Poor response to conventional treatment for two weeks, with symptoms showing no remission or progressive aggravation; 6. Well-controlled tumor for ≥3 months; 7. No significant abnormalities in liver and renal function: alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 times the upper limit of normal (ULN); serum creatinine (Cr) and blood urea nitrogen (BUN) ≤ 2 times the upper limit of normal (ULN); 8. Expected lifespan of the subject ≥ 3 months; 9. The patient is informed of the study details and voluntarily signs the informed consent form; 10. Willing and able to receive treatment and complete follow-up in accordance with the protocol requirements, and able to adhere to the doctor's advice for basic treatment. Exclusion Criteria: 1. Severe cardiac insufficiency (e.g., NYHA classification Grade Ⅲ or Ⅳ) and uncontrolled hypertension with medication (systolic blood pressure ≥ 160 mmHg or diastolic blood pressure ≥ 110 mmHg); 2. Positive results for hepatitis B, hepatitis C, human immunodeficiency virus (HIV), or syphilis; 3. Eastern Cooperative Oncology Group (ECOG) performance status score ≥ 2; 4. Currently participating in another clinical trial or having participated in another clinical trial within 4 weeks; 5. Patients with an allergic diathesis or known allergy to the preparation used in this trial; 6. Patients with comorbid mental illness who are unable to cooperate with treatment; 7. Pregnant or lactating women.