Dual-engineered extracellular vesicles enabling endothelial targeting and EphrinB2 delivery for pulp revascularization

Dental pulp pathologies impair quality of life and systemic health. Obstacles to revascularization remain a key challenge in regenerating dental pulp tissue. To address these challenges, dual-engineered extracellular vesicles (EVs) incorporating EphrinB2 as a pro-regenerative payload alongside the DNA aptamer Apt02 for endothelial-targeting specificity were developed. This study identified 1 µg/mL as the optimal concentration for fabricating EphrinB2-loaded extracellular vesicles (B2-EVs). At this concentration, B2-EVs significantly enhanced the proliferation, migration, and capillary morphogenesis of HUVECs. Subsequent integration of the endothelial-targeting Apt02 yielded Apt-B2-EVs, which demonstrated superior affinity for HUVECs and amplified pro-angiogenic capacity. Mechanistic analyses confirmed that Apt-B2-EVs promoted angiogenesis by activating the EphrinB2/EphB4 axis, thereby triggering downstream Akt/ERK1/2 phosphorylation. These vesicles were further encapsulated within methacrylated gelatin (GelMA) hydrogel, exhibiting sustained release kinetics and excellent biocompatibility. Implantation of Apt-B2-EVs@GelMA into root canals established pulp organoids, which, upon ectopic transplantation in nude mice, robustly enhanced vascularization. The dual-engineered Apt-B2-EVs present a potent strategy for recruiting endothelial cells and delivering EphrinB2 to enable functional pulp revascularization within root canal niches, laying a translational foundation for next-generation functional pulp regeneration.