Inclusion Criteria:
1. Ability to understand the study protocol and voluntarily sign the written informed consent form;
2. A clear diagnosis of type II diabetes mellitus for more than 3 years, with poor blood glucose control under conventional treatment (HbA1c ≥ 7.5% for 3 consecutive months);
3. Age 18-75 years old, with a body mass index (BMI) of 18.5-35 kg/m²;
4. Fasting C-peptide level 0.3-1.5 ng/mL, indicating residual islet function;
5. Karnofsky performance score (KPS) ≥ 70, with good daily living ability;
6. Life expectancy \> 5 years;
7. Normal liver and kidney functions (bilirubin \< 1.5×ULN, ALT/AST \< 2.5×ULN, creatinine \< 1.5×ULN); normal blood routine (absolute neutrophil count ≥ 1.8×10\^9/L, platelets ≥ 100×10\^9/L);
8. No serious heart, brain, lung and other important organ diseases, and stable vital signs;
9. Women of childbearing age have a negative pregnancy test within 7 days before enrollment, and all subjects of childbearing age agree to take effective contraceptive measures during the study and within 1 year after the end of the study; Willing to cooperate with the whole course of follow-up and complete all examination and observation indicators.
Exclusion Criteria:
1. Type 1 diabetes mellitus or other special types of diabetes;
2. Severe diabetes-related complications, such as end-stage renal disease, severe proliferative retinopathy, diabetic foot with ulcer and infection, etc.;
3. A history of malignant tumors within 5 years, or current suspicious malignant tumor lesions;
4. HIV, hepatitis B, hepatitis C and other infectious diseases with positive pathogen indicators;
5. Active autoimmune diseases, or long-term use of glucocorticoids and immunosuppressants (except for small dose hormone replacement therapy);
6. A history of severe allergic reactions, or allergy to the components of the study cell preparation;
7. Pregnant or lactating women;
8. Actively participating in other clinical research projects at the same time;
9. Mental diseases or poor compliance that cannot cooperate with the study; Other conditions that the investigator deems unsuitable for participating in the study.
