Human Platelet-derived Lysates and Extracellular Vesicles Restore Mitochondrial Function and Redox Balance in Neuronal Models

Mitochondrial dysfunctions, characterized by impaired bioenergetics and redox imbalance, are hallmarks of neurodegenerative diseases. Human platelet pellet lysates (HPPL) and platelet extracellular vesicles (PEVs) contain antioxidants and trophic factors that may protect neurons from mitochondrial injury. The present study evaluated the effects of HPPL and PEVs against rotenone-induced mitochondrial dysfunction in N2A and SH-SY5Y neuronal cell lines as well as in zebrafish embryos. HPPL and PEVs were prepared from clinical-grade platelet concentrates; protein content and antioxidant capacity were quantified, and PEVs were further characterized for size, particle concentration, platelet and EV markers. Neuronal cells were pretreated with 5% HPPL or PEVs before rotenone (5 {micro}M) exposure; embryos received 20 g/mL HPPL or PEVs before rotenone (200 nM). Mitochondrial assessments included ATP production, reactive oxygen species (ROS) generation, mitochondrial membrane potential ({Delta}{Psi}m), ultrastructure, and expression of biogenesis and fusion markers. Impact on cell viability was also determined. Our in vitro data demonstrate that both HPPL and PEVs restored ATP, reduced ROS, preserved {Delta}{Psi}m and morphology, as well as upregulated PGC-1 and MFN1, ultimately leading to increased cell survival. In zebrafish, pretreatment with platelet biomaterials improved developmental abnormalities, survival and hatching, reduced ROS, and preserved mitochondrial ultrastructure. These findings demonstrate that HPPL and PEVs protect against complex I inhibition by restoring mitochondrial function and redox balance, supporting their current development as scalable cell-free biotherapies for neurodegenerative disorders.