The Therapeutic Potential of Amniotic Fluid Stem Cell Derived Treatments (“Secretomix”) for Necrotising Enterocolitis

Abstract

Background: Necrotising enterocolitis (NEC), an inflammatory disease of the gut, remains a significant challenge in neonatal care, with morbidity and mortality rates that have not substantially improved despite advancements in treatment. Stem cells (SCs) have become a treatment strategy for other intestinal diseases, which share some similarities with NEC. However, due drawbacks of using SCs in therapy, such as tumorgenicity and ethical concerns, there has been a shift towards using SC-derived products. This study aims to evaluate the therapeutic potential of Secretomix, a drug of extracellular vesicle (EVs) derived from amniotic fluid SCs, on a well-established rat model of NEC. Methods: A series of experiments were done to optimise the rat model using stressors such as lipopolysaccharide (LPS), hyperosmolar milk formula, and hypoxia. Different feeding volumes and hypoxia durations were tested. Two formulations of Secretomix were administered via intraperitoneal injections at 80ul and compared with sham and control groups. Animals were monitored for the duration of the experiment using specific parameters for clinical sickness scores. After harvest, the gut is also assessed using three different parameters for macroscopic scores. H&E stained histology sections are used for NEC severity grading. Results: Weight-dependent feeding volumes and prolonged hypoxia were found to be too severe for neonatal rats, leading to rapid deterioration. Adjustments to weight-independent feeding volumes and reduced hypoxia exposure improved consistency in disease manifestation but did not mitigate the overall severity of NEC in the treatment groups. Contrary to our hypothesis, the Secretomix treatment groups exhibited greater disease severity and higher clinical sickness scores compared to sham. Conclusion: Despite the promising potential of SC-derived EVs observed in other studies, Secretomix did not demonstrate protective effects against NEC in this rat model. Instead, treated groups showed increased disease severity, with clear signs of pneumatosis intestinalis. Future research should focus on further optimising animal models, refining treatment formulations, and conducting rigorous toxicity evaluations to better understand the mechanisms and potential therapeutic potential of Secretomix in NEC.