To study the safety and efficacy of intranasal administration of exosomes derived from mesenchymal stromal cells on long-term neurodevelopmental outcome in extremely low birth weight infants born at gestational age 25/0-27/6 weeks.

Surviving extremely low birth weight (ELBW) infants are at risk of severe neurodevelopmental disability. Exosomes or extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) can mediate a variety of different effects, including synaptic plasticity, nutritional metabolic support, nerve regeneration, inflammatory response, anti-stress effect, cellular waste disposal, treating neurological injury, preventing hemorrhagic and ischemic brain lesions, playing an important role in health and neuroprotection in extremely premature newborns during neonatal intensive care.

The proposed blinded randomized controlled trial was designed to compare the effect of intranasal administration of exosomes on long-term neurodevelopmental outcome in ELBW infants.

ELBW infants will be randomized to receive (group 1) and not receive exosomes (control group).

Group 1 - Neonates will receive exosomes (1 dose will be obtained from a daily conditioned culture medium of 120 million MSCs) suspended in 500 µl of phosphate buffer in each nostril at 50 µl with an interval of 2-3 minutes. The therapeutic course will consist of 5 instillations with an interval of 1 days.

The primary outcome measure is the incidence of death, the incidence of survival with any of either severe intraventricular hemorrhage (IVH), cystic periventricular leukomalacia (PVL), or brain injury on cranial ultrasound and MRI or major neurodevelopmental impairment determined at 36 months of age corrected for prematurity (where major neurodevelopmental impairment is defined as any of the following: cognitive deficit, cerebral palsy, or severe visual or hearing impairment. Cognitive delay defined as mental developmental index (MDI) score of the Griffiths-II and Bayley Scales of Infant Development (2nd edition) < 85, cerebral palsy, or severe visual or hearing impairment.

To investigate this outcomes and the mechanisms by which extracellular vesicles (EVs) might effect we will analyze the biomarkers of perinatal brain injury (S-100, NSE, EPO) and mRNA.

Key secondary outcomes are incidences of short term outcomes: individual components of the composite primary outcome, survival with and without major neonatal morbidity including severe retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC).

Safety analyses will assess the injures or damages of the nasal mucosa, allergic reaction to EVs and any adverse events after intranasal administration of EVs.

The results of this trial may help to improve the quality of life of ELBW infants and reduce long-term health care costs.

Inclusion Criteria:

• Premature newborns of gestational age (GA) 25/0-27/6 weeks,

Exclusion Criteria:

• Missing written parental consent
• Damages to the nasal mucosa
• Maxillofacial defects
• Major congenital anomalies (including chromosomal aberrations, cyanotic congenital heart defects, syndromes likely affecting long-term outcome, and major congenital malformations requiring surgical correction during newborn period)
• Infants who died before 48 hours, infants in whom the clinical decision to withhold intensive care was made, infants who were not considered viable
• Infants with edematous hemolytic disease of newborns, non-immune fetal dropsy,
• Multifetal Gestations
• Participation in another study with ongoing use of an unlicensed investigational product from 28 days before study enrollment until the end of the study