Safety and Efficacy of Allogeneic MSCs in Promoting T-regulatory Cells in Patients With Small Abdominal Aortic Aneurysms

Inclusion Criteria: * Be 40 and 85 years of age. * Have diagnosis of noninflammatory degenerative infrarenal abdominal aortic aneurysms measuring 3-5 cm. in diameter by Computed Tomography (CT) scan. * Females of childbearing potential must be willing to use one form of birth control for the duration of the study. Female participants must undergo a blood or urine pregnancy test at screening. Exclusion Criteria: * Inflammatory AAA defined by a thickened aortic wall and retroperitoneal fibrosis and adhesions of peritoneal organs, and elevated erythrocyte sedimentation rate or in the opinion of investigator. * Mycotic AAA defined as saccular morphology, a positive blood culture, fever, or in the opinion of the investigator. * Symptomatic, Saccular, or any AAA associated with thoracic aorta dilatation \>5.0 cm. * Infra-renal AAA associated with Marfan's or Ehlers-Danlos Syndrome or other connective tissue disorders. * Common or external iliac artery aneurysm \> 30 cm. in maximal transverse diameter. * AAA due to dissection. * Allergy to iodine contrast. * History of cancer within the last 5 years, except basal cell skin carcinoma with clean border pathology report. * Estimated glomerular filtration rate (eGFR) \< 30mL/min. * Any condition requiring immunosuppressant medications (e.g., for treatment of organ transplants, psoriasis, Crohn's disease, alopecia areata, rheumatoid arthritis, scleroderma, lupus). * Acute coronary syndrome (ACS) in the last 30 days prior to enrollment.\* * Congestive heart failure (CHF) hospitalization within the last 30 days prior to enrollment.\* * HIV or Hepatitis C (HCV) positive. * Contraindication to Computed Tomography or known allergy to contrast media. * Any bleeding diathesis defined as an International Normalized Ratio (INR) 2.0 (off anticoagulation therapy) or history of platelet count less than 70,000 or hemophilia. * Pregnant or breast-feeding women. * Significant hepatic dysfunction (alanine transaminase (ALT) or aspartate aminotransferase (AST) greater than 2 times normal). * Life expectancy less than two years. * Inability to provide written informed consent due to cognitive or language barriers (interpreter permitted). * Presence of any clinical condition that in the opinion of the PI or the sponsor makes the patient not suitable to participate in the trial. * As defined by the standard definitions of CHF and ACS by the American Heart Association.