Selection of a novel MSC-targeted aptamer Pt-1 and its functionalized hydrogel for tissue regeneration

Mesenchymal stem cell (MSC)-based therapies present substantial opportunities for regenerative medicine, yet the absence of lineage-specific tools for precise cell recruitment constitutes a primary limitation. In this study, we developed a novel ssDNA aptamer, designated as Pt-1, specifically evolved against human dental pulp stem cells (hDPSCs) using Cell-SELEX technology. Pt-1 exhibited high target specificity, strong binding affinity, and favorable physiological stability. Notably, Pt-1 identified a distinct subpopulation within heterogeneous DPSCs; the Pt-1^high subset displayed significantly enhanced proliferative capacity and osteo/odontogenic potential compared to the Pt-1^Low group. Through proteomic analysis and molecular docking, we elucidated that Pt-1 recognizes Cav1-associated target as its membrane target. To translate this molecular recognition into a regenerative strategy, we engineered a Pt-1-functionalized ChSMA hydrogel. This bio-instructive scaffold demonstrated superior efficacy in orchestrating the homing of endogenous MSCs in vitro and in vivo compared to the established Apt19S aptamer. In rat models of dental pulp and femoral bone defects, the Pt-1-modified hydrogel significantly accelerated tissue restoration, promoting more mature trabecular bone formation and pulp tissue regeneration. In summary, we developed a novel ssDNA aptamer targeting MSCs and established an aptamer-based strategy for precise endogenous cell recruitment, opening new therapeutic avenues for regenerative medicine.