Anti-inflammatory potential of plant-derived extracellular vesicles from Solanum nigrum L. integrated in gelatine-dopamine hydrogel on RAW 264.7 and MC3T3 cells.

Abstract

Background and purpose: Plant-derived extracellular vesicles (PDEV) from Solanum nigrum L. fruit show promise as a cell-free regenerative and inflammatory therapy for bone defects due to their anti-inflammatory properties. However, challenges such as storage stability and targeted delivery efficiency remain in PDEV's applications. Strategies such as lyophilization and injectable hydrogel delivery systems offer potential solutions.

Experimental approach: In this study, lyophilized PDEVs derived from Solanum nigrum L. berries were incorporated into a thermosensitive injectable gelatine-dopamine (Gel-Dop) hydrogel and evaluated by in vitro for their anti-inflammatory potential using MC3T3 pre-osteoblast cells and RAW 264.7 macrophage cells.

Key results: The isolated PDEVs show a spherical morphology, an average size of approximately 132.6 nm, a polydispersity index of 0.197, and a protein concentration of 509 μg mL^-1. These PDEVs were efficiently internalized by MC3T3 and RAW 264.7 cells after 12 hours of incubation and showed no cytotoxic effects at concentrations up to 10 μg mL^-1. The release profile confirmed that the hydrogel effectively released the PDEVs, which remained non-toxic and were internalized by cells after 12 hours of incubation. Subsequently, treatment of lipopolysaccharide (LPS) stimulated MC3T3 and RAW 264.7 cells with PDEVs led to a reduction in IL-6 protein expression.

Conclusion: These findings suggest that lyophilized PDEVs from Solanum nigrum L. berries, when incorporated into Gel-Dop hydrogel, hold promise for future development as an anti-inflammatory agent in bone therapy. This study is the first to characterize and incorporate lyophilized PDEVs from Solanum nigrum L. into thermosensitive injectable Gel-Dop hydrogel and demonstrate their anti-inflammatory potential through the suppression IL-6 expression in LPS-stimulated MC3T3 and RAW 264.7 cells.