Apt19s-functionalized 3D-printed PCL/58S bioactive glass scaffolds via thiol-maleimide click chemistry enhance hBMSC...

This study presents a novel aptamer-functionalized 3D-printed scaffold designed to promote adhesion and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Composite scaffolds consisting of 55 wt% polycaprolactone (PCL) and 45 wt% 58S bioactive glass (BG) were fabricated using fused deposition modeling (FDM). Surface biofunctionalization was achieved through thiol-maleimide click chemistry to covalently immobilize thiol-terminated Apt19s aptamer. Successful conjugation was confirmed by carbon quantum dot labeling and fluorescence microscopy. In vitro evaluations demonstrated that Apt19s-modified scaffolds (scaffold/Mal/Apt) significantly enhanced hBMSC adhesion and spreading, as shown by SEM and cytoskeletal staining. Metabolic activity reached 157.8 ± 3.7% on day 5 (p < 0.001), markedly higher than that of the controls. Osteogenic differentiation was substantially accelerated, evidenced by significantly higher mineral deposition (1.92 ± 0.04 AU vs. 1.39 ± 0.04 AU, p < 0.01) and peak ALP activity of 1.88 ± 0.03 on day 14. Moreover, key osteogenic genes were strongly upregulated, including Runx2 (4.3-fold) and OCN (6.1-fold) by day 28. These findings suggest that the combination of bioactive ion release from 58S BG and aptamer-mediated cell capture creates a favorable microenvironment for osteogenic differentiation in vitro.