Phase I/IIa Clinical Trial of Human Umbilical Cord Mesenchymal Stem Cell Injection in the Treatment of Idiopathic Pulmonary Fibrosis (IPF)

Inclusion Criteria: 1. Age 40-75 years (inclusive), regardless of gender; 2. Diagnosed with idiopathic pulmonary fibrosis (IPF) according to the 2018 diagnostic guidelines jointly issued by the American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS), and Latin American Thoracic Association (ALAT); 3. Subjects with typical HRCT imaging manifestations of IPF (honeycombing, traction bronchiectasis or bronchiolectasis (mainly appearing in ground-glass opacities and fine reticular opacities)) within 12 months prior to screening; 4. Subjects whose disease is assessed by the investigator as stable within 3 months prior to dosing, with diffusing capacity for carbon monoxide (DLCO) at 30%-79% of the predicted value (adjusted for Hb), and FVC/predicted value ≥50%; 5. Blood biochemical tests must meet the following criteria: alanine aminotransferase (ALT) ≤1.5×ULN, aspartate aminotransferase (AST) ≤1.5×ULN, total bilirubin (TBIL) ≤1.5×ULN, direct bilirubin (DBIL) ≤1.5×ULN, serum creatinine (Cr) ≤1.5×ULN; 6. Expected survival ≥12 months; 7. Subjects with good compliance, who are able to understand and cooperate in performing pulmonary function tests, and are willing to receive medication as required by the protocol and undergo follow-up examinations on schedule; 8. Subjects who voluntarily participate in the trial, understand, and sign the informed consent form. Exclusion Criteria: 1. Subjects, who have previously received stem cell therapy, are intolerant to cell therapy, or have taken drugs that may cause or exacerbate pulmonary fibrosis (such as amiodarone, bleomycin, or methotrexate, etc.); 2. Subjects with interstitial lung disease (ILD) other than IPF, including but not limited to: any other type of interstitial pneumonia; lung diseases associated with exposure to fibrogenic agents or other environmental toxins or drugs; other types of occupational lung diseases; granulomatous lung diseases; pulmonary vascular diseases; systemic diseases, including vasculitis, infectious diseases (i.e., tuberculosis), and connective tissue diseases; 3. Subjects currently requiring oxygen therapy (oxygen therapy time ≥15 hours/day); 4. Subjects with a history of mechanical ventilation or concurrent infectious pneumonia or asthma within 1 month prior to screening; 5. Subjects with a history of malignancy within 5 years prior to screening; 6. Subjects who have been hospitalized three or more times due to acute exacerbation of IPF or other respiratory diseases within 1 year prior to screening; 7. Evidence of current digestive, urinary, cardiovascular, cerebrovascular, hematological, neurological, psychiatric, or metabolic diseases that may affect safety, such as poorly controlled type 2 diabetes (fasting blood glucose ≥10.0 mmol/L or HbA1c ≥8.5%) or poorly controlled hypertension (≥160/100 mmHg). 8. History of psychotropic drug abuse or drug addiction; 9. Known history of immune system diseases (e.g., thymic diseases, systemic lupus erythematosus); 10. Subjects with positive serological virology tests (HBsAg, HCV antibody, HIV antibody, Treponema pallidum antibody); however, hepatitis B virus carriers, stable hepatitis B patients after drug treatment (DNA titer ≤500 IU/mL or copy number \<1000 copies/mL), and cured hepatitis C patients (HCV RNA negative) may be enrolled after being deemed eligible by the investigator; 11. Subjects allergic to human albumin, anesthetic drugs, or any of their components; 12. Subjects who have participated in any other clinical trial within 3 months prior to screening; 13. Subjects who cannot tolerate bronchoscopy (including but not limited to the following conditions: active massive hemoptysis; severe hypertension and arrhythmia; myocardial infarction within 4-6 weeks prior to screening or history of unstable angina; severe cardiopulmonary dysfunction; uncorrectable bleeding tendency (platelet count \<60×109/L), such as severe coagulation disorders, uremia, and severe pulmonary hypertension; severe superior vena cava obstruction syndrome; suspected aortic aneurysm; multiple pulmonary bullae; extreme systemic exhaustion); 14. Subjects deemed by the investigator to be at high risk for general/local anesthesia; 15. Pregnant or lactating women, or those with a positive β-human chorionic gonadotropin (β-HCG) test during screening, or those unable or unwilling to adopt effective non-pharmacological contraceptive measures during the study and for 6 months after study completion; 16. Other circumstances deemed by the investigator as unsuitable for participation in this trial.