Umbilical cord mesenchymal stem cells (SC) transplantation was a novel therapy for diabetes mellitus, with less side effects and more advantages. Clinical trials had verified that good metabolic control would be achieved when Liraglutide (GLP-1) was added to the conventional therapies. The investigators hypothesized that the combined therapy of umbilical cord mesenchymal stem cells transplantation and Liraglutide in type 2 diabetes mellitus will aid the differentiation of stem cells into insulin-producing cells, improve the survival of differentiated cells, protect the residual beta-cells and improve insulin secreting function, so as to achieve a favorable glucose homeostasis.

Inclusion Criteria:

• Male and female patients age 35 to 65 years of age.
• Ability to provide written informed consent.
• Mentally stable and able to comply with the procedures of the study protocol.
• Clinical history compatible with type 2 diabetes (T2DM) as defined by ADA(1997) on the Diagnosis and classification of Diabetes Mellitus
• Basal C-peptide 0.5-2.0 ng/mL
• HbA1c ≥ 7.5 and ≤ 11% before standard medical therapy (SMT).
• Patients must have been treated with SMT for 1-4 months prior to matching. Insulin dose and metformin doses should be stable over 1 month prior to matching.
• HbA1c ≥ 7.5 and ≤ 10% at time of matching.
• Total insulin daily dose (TDD) at time of matching should not exceed 1.0 units/day/kg
• 18.5 kg/㎡≤BMI≤40.0kg/㎡

Exclusion Criteria:

• Abnormal liver function >2.5 x ULN
• Evidence of renal dysfunction:serum creatinine > 1.5 mg/dl (males) and 1.3 mg/dl (females).
• Gastrointestinal operation history.
• Type 1 Diabetes mellitus; DKA; secondary diabetes.
• Uncontrolled blood Pressure: SBP >180 mmHg or DBP >100 mmHg at the time of matching.
• Evidence of cardiovascular disease, existing congestive cardiac failure on physical exam and/or acute coronary syndrome in past 6 months.
• Presence of active proliferative diabetic retinopathy or macular edema.
• Any acute or chronic infectious condition that in the criteria of the investigator would be a risk for the patient.
• For female participants: Positive pregnancy test, presently breast-feeding, or unwillingness to use effective contraceptive measures for the duration of the study. For male participants: intent to procreate 3 months before or after the intervention or unwillingness to use effective measures of contraception. Oral contraceptives, Norplant?, Depo-Provera?, and barrier devices with spermicide are acceptable contraceptive methods; condoms used alone are not acceptable.
• Active infection including hepatitis C, HIV, or TB as determined by a positive skin test or clinical presentation, or under treatment for suspected TB.
• Subjects that are being treated with any medication that could interfere with the outcome of the study such as: Thiazolidinediones and other glucagon like peptide 1 (GLP-1) analogues (Exenatide, Byetta), Pramlintide (Amylin), Dipeptidyl-peptidase IV (DPP-IV) inhibitors (i.e. Sitagliptin, Januvia)
• Any known or suspected allergy to liraglutide or other relevant products.
• Evidence of thyroid adverse events (serum calcitonin increase, goiter, thyroid cancer, et al) or pancreatitis caused by other GLP-1 analogues.
• Subjects with past history or family history of Medullary Thyroid Carcinoma(MTC) or Multiple Endocrine Neoplasia Syndrome Type 2(MEN2) .