3D-printed scaffolds: Incorporating dexamethasone microspheres and BMP2 for enhanced osteogenic differentiation of human mesenchymal stem cells

Abstract

This study investigates the fabrication and evaluation of 3D-printed scaffolds (G-scaffolds) incorporating dexamethasone-loaded microspheres (Dex-M) and bone morphogenetic protein 2 (BMP2) to enhance osteogenic differentiation of human mesenchymal stem cells (hMSCs). Dex-M was prepared using an ultrasonic atomizer, achieving a high encapsulation efficiency and uniform particle size. The G-scaffolds were precisely printed using photoactive bioprinting, creating Dex-M+BMP2 +G-scaffolds. In vitro release studies demonstrated sustained Dex release over 6 weeks, with the Dex-M+BMP2 +G-scaffold significantly reducing the initial burst release and maintaining stable levels of osteogenic factors. Cytotoxicity assays confirmed the biocompatibility of the scaffolds, showing no adverse effects on hMSC viability. Osteogenic differentiation was assessed via RT-PCR, revealing that the Dex-M+BMP2 +G-scaffold exhibited the highest expression levels of critical osteogenic markers (ON, OP, OC, and COL1A) compared with the other scaffold formulations. Calcium deposition and elemental analysis also demonstrated enhanced mineralization in the Dex-M+BMP2 +G-scaffold group, with calcium and phosphate levels 3.9–1.7 times higher than in the other groups. Overall, the Dex-M+BMP2 +G-scaffold effectively promoted osteogenic differentiation and mineralization of hMSCs, underscoring its potential as a promising biomaterial for bone tissue engineering applications.