Clinical Research Directory

Inclusion Criteria: Signed informed consent form. Diagnosis of Crohn's disease (CD) confirmed at least 6 months prior to screening, based on the Chinese Consensus on Diagnosis and Treatment of Inflammatory Bowel Disease (2018, Beijing). Crohn's Disease Activity Index (CDAI) score ≤220, indicating inactive or mildly active CD. Presence of complex anal fistula confirmed by clinical and MRI evaluation. Age 18-60 years (inclusive), regardless of sex. Negative serum/urine pregnancy test for women of childbearing potential; all participants must agree to use effective contraception during and for 6 months after the trial. Good general health status confirmed by medical history and relevant examinations. Exclusion Criteria: CDAI \>220 or requiring immediate treatment for active CD. Patients with rectal/anal stenosis or active proctitis (due to procedural limitations). Presence of abscess \>2 cm unless treated ≥2 weeks prior to the trial. History of fistula surgery (except drainage or seton placement), concurrent need for perianal surgery unrelated to fistula, or anticipated need for such surgery within 24 weeks post-treatment. Systemic steroid therapy within 4 weeks prior to screening. Abnormal laboratory results: Liver function: Total bilirubin ≥1.5×ULN; aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥2.5×ULN. Renal function: Creatinine clearance \<60 mL/min or serum creatinine ≥1.5×ULN (measured or calculated by Cockcroft-Gault formula). Current or history of malignancy (including fistula-related carcinoma). Severe, progressive, or uncontrolled hepatic, hematologic, gastrointestinal (excluding CD), endocrine, pulmonary, cardiac, neurologic, psychiatric, or cerebral diseases. HIV/syphilis antibody positivity, active HCV/HBV infection, or active tuberculosis. Known allergy to antibiotics or trial-related agents (e.g., penicillin, streptomycin, gentamicin, aminoglycosides, human serum albumin, human platelet lysate, DMEM cell culture medium, or bovine-derived materials). Intolerance to anesthesia or contraindications to MRI scanning (e.g., pacemaker, hip prosthesis, severe claustrophobia, gadolinium allergy). Pregnancy, lactation, or refusal to use effective contraception during and for 6 months post-trial. Major surgery or severe trauma within the past 6 months. History of alcohol/drug abuse within 6 months prior to enrollment. Use of investigational drugs within 12 weeks (84 days) prior to screening. Inability to comply with the study protocol or other conditions deemed unsuitable by investigators.