Phase IIa clinical trial, pilot, single centre, prospective, randomized, double-blind, placebo-controlled, with sequential inclusion of patients

20 Patients presenting with a moderate-severe acute ischemic stroke who will be randomized in a 1:1 proportion to intravenous treatment with allogeneic stem cells from adipose tissue or to placebo (vehicle).

Inclusion criteria:

• Male or female acute ischemic patients aged 60-80 years with symptoms of acute cerebral infarction of less than 12h from stroke onset. If the time of symptom onset is unknown, it shall refer to the last time the patient was asymptomatic seen.
• Patients should be treated within two weeks from the onset of stroke symptoms.
• Patients with a measurable focal neurological that must persist to the time of treatment without clinically meaningful improvement.
• Patients must have computerized tomography (CT) and / or magnetic resonance imaging (MRI) compatible with the clinical diagnosis of acute ischemic stroke in the territory of the middle cerebral artery before being included in the study.
• Patients must have a score on the NIH Stroke Scale 8-20, with at least 2 of these points in Sections 5 and 6 (motor deficit) at the time of inclusion.
• Immediately (i.e. few minutes) before the stroke, patients should have a score on the mRS ≤ 1 (no symptoms at all or no significant disability despite symptoms, able to perform everyday tasks and activities).
• Women of childbearing age should have a negative pregnancy test performed prior to inclusion.
• Obtaining informed consent signed (after a detailed explanation of the nature and purpose of this study, the patient or guardian or legal representative must give their consent to participate by signing the informed consent document). Assent from a relative or career if the patient is unable to give meaningful consent (e.g. in cases of dysphasia, confusion, or reduced conscious level).

Exclusion criteria:

• Comatose patients. Patients with a score of 2 or more in the item 1a of the NIHSS related to the degree of awareness.
• Evidence on neuroimaging (CT or MRI) of brain tumour, cerebral oedema with midline shift and clinically significant compression of ventricles, cerebellar infarction or brainstem, or intraventricular, intracerebral or subarachnoid haemorrhage.
• Current drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements.· Active infectious disease, including HIV, hepatitis B, Hepatitis C, etc.
• Pre-existing dementia.
• Specify health status or any clinical conditions (e.g., life expectancy, co-existing disease) or other characteristics that precludes appropriate diagnosis, treatment or follow-up in the trial.
• Patients who are participating in another clinical trial.
• Inability or unwillingness of individual or legal guardian/representative to give written informed consent.