Exosomal miRNA combined with anti-inflammatory hyaluronic acid-based 3D bioprinted hepatic patch promotes metabolic reprogramming in NAFLD-mediated fibrosis.

Non-alcoholic fatty liver disease (NAFLD) is a complex metabolic disorder, where the underlying molecular mechanisms are mostly not well-understood and therefore, warrants the need for therapeutic interventions targeting several metabolic pathways as a unified response. Of late, promising outcomes have been observed with mesenchymal stem cell-derived exosomes. However, reduced bioavailability due to systemic delivery and the need for repeated fresh isolation hinders their feasibility for clinical applications. In this regard, an 'off-the-shelf' 3D bioprinted hyaluronic acid-based hepatic patch to deliver encapsulated exosomes alone/or with hepatocytes (as dual-therapy) is developed as a holistic approach for ameliorating the disease condition and promoting tissue regeneration. The bioprinted hepatic patch demonstrated sustained and localized release of exosomes (∼82 % in 21 days), and healthy liver tissue-like mechanical properties while being biocompatible and biodegradable. Assessment in NAFLD rat models displayed alleviation of the altered biochemical parameters such as fat deposition, deranged liver functions, disrupted lipid, glucose, and insulin metabolism along with a reduction in localized inflammation, and associated liver fibrosis. The study suggests that a synergistic effect between the miRNA population of released exosomes, cell therapy, and the bioprinted matrix materials is crucial in targeting multiple complex metabolic pathways associated with the severity of the disease.