Umbilical cord mesenchymal stem cell injection expressing OCN19, while playing the role of MSCs, can directly stimulate the expression of insulin gene and the division and proliferation of islet beta cells, which is expected to further enhance the therapeutic effect of stem cells. In non-clinical studies, it was found that MSCs expressing OCN19 had better hypoglycemic effect than MSCs

1. Inclusion Criteria:

   1. Accoding to WHO diagnostic standards, patients with type 2 diabetes (fasting blood glucose ≥ 7.0 mmol/L), 30-75 years old, regardless of gender;
   2. Able to clearly understand the purpose of clinical trials and comply with trial requirements, willing to participate in this study, and sign an informed consent form;
   3. 20kg/m2 ≤ Body Mass Index (BMI) ≤ 30 kg/m2;
   4. 7.5% ≤ glycated hemoglobin ≤ 10%;
   5. Insulin should be subcutaneously injected for more than six months, and insulin and/or other oral hypoglycemic drugs (limited to metformin only) should be used α The dosage of glycosidase inhibitors remained stable for the first 3 months before randomization;
   6. During the study period, all males and females with reproductive potential were willing to accept the use of efficient contraceptive methods.

2. Exclusion Criteria:

   1. 1 Type diabetes, pregnancy diabetes or other special type diabetes patients;
   2. Patients with severe allergic constitution or allergic to any ingredients used in cell culture;
   3. Patients who have used drugs that affect glucose metabolism within the past month, such as glucocorticoids, thiazide diuretics, oral contraceptives, tricyclic antidepressants, etc;
   4. Screening the patients with acute complications such as diabetes ketoacidosis and non ketotic hyperosmolar syndrome in recent 6 months;
   5. Serious cardiovascular and cerebrovascular events such as NYHA grade III or IV heart failure, myocardial infarction, cerebral infarction, and cerebral hemorrhage occurred within the past 6 months;
   6. Patients with abnormal blood routine (including white blood cell or neutrophil count below the lower limit of normal, abnormal platelet count, and hemorrhagic disease);
   7. Patients with liver and kidney dysfunction: such as serum bilirubin TBIL exceeding the upper limit of normal by 1.5 times, AST and ALT exceeding the upper limit of normal by 2.5 times, and serum creatinine exceeding 1.5 mg/dl for males and 1.4 mg/dl for females;
   8. Patients with other serious systemic diseases (such as malignant tumors, central nervous system, cardiovascular system, blood system, digestive system, endocrine system, respiratory system, urogenital system, immune system, etc.);
   9. Individuals who are currently using systemic hormones (such as glucocorticoids), immunosuppressants, or cytotoxic therapy;
   10. Patients who received antibiotic treatment within the three months prior to study registration;
   11. Patients who have received live or attenuated vaccines within 4 weeks prior to registration, or plan to receive live or attenuated vaccines during the study period;
   12. Patients who are positive for HbsAg, Anti HCV, HIV or syphilis;
   13. Patients with active infection (such as hepatitis B or hepatitis C, tuberculosis) requiring treatment;
   14. Fever related diseases of unknown origin;
   15. Disabled patients (blind, deaf, mute, intellectually disabled, physically disabled) and individuals with mental illnesses;
   16. Patients who use drugs or have a history of adverse drug abuse and alcohol dependence within 5 years (with mental or substance abuse disorders that may interfere with the requirements of the trial);
   17. Patients of childbearing age who are pregnant or lack effective contraceptive measures or have a pregnancy plan, as well as breastfeeding patients;
   18. Patients who have received other stem cell treatments or participated in other clinical studies within the first three months of screening;
   19. Patients who have not recovered due to adverse events (≥ level 2) caused by drug treatment within 4 weeks prior to the start of the study;
   20. Patients with congenital or acquired immune dysfunction or a history of organ transplantation;
   21. Patients with other serious diseases that may affect infusion results;
   22. According to the judgment of the researchers, patients whose clinical conditions are not suitable for inclusion in this study.-