Safety of Escalating Doses of Intravenous Bone Marrow-Derived Mesenchymal Stem Cells in Patients With a New Ischemic Stroke

Inclusion Criteria: * 1\. Ischemic stroke in the middle cerebral artery territory, with onset 24-72 hours prior to the time that the therapy transfusion is initiated, radiologically confirmed, and with either diameter \>15 mm or volume \> 4cc. * 2\. The index stroke has clinical deficits that are moderate-severe (NIHSS score 7-20), did not require hemicraniectomy or invasive intracranial pressure monitoring, and was not associated with a concomitant STelevation myocardial infarction. * 3\. Age 18-80 years, inclusive * 4\. Reasonable likelihood of receiving standard post-stroke medical care, as well as standard physical, occupational, and speech therapy. Exclusion Criteria: * 1\. No substantial pre-stroke disability (pre-stroke modified Rankin Scale score 0-2). * 2\. Females of child-bearing potential will be excluded unless (1) a negative urine pregnancy test is obtained and (2) the patient has been effectively using contraceptive method with known failure rate \<1 % for at least 90 days. * 3\. Lactating mothers * 4\. If thrombolytic therapy has been administered, at least 24 hours have passed between completing thrombolytic dosing and initiating the current study's transfusion. * 5\. Known allergy to penicillin or to fetal bovine serum * 6\. Active co-existent major neurological or psychiatric disease that could significantly interfere with patient compliance or study assessments, including drug or alcohol abuse. * 7\. Any diagnosis that makes survival to 1-year post-stroke unlikely. * 8\. Participation in any other experimental therapeutic clinical trial concurrently or in the prior three months. * 9\. Contraindication to undergoing MRI scanning.