Hydroxyapatite Gradient Poly (Vinyl Alcohol)/Bacteria Cellulose Bone Scaffold via Buoyancy-Driven Gradient Method

The repair of bone defects necessitates the establishment of sophisticated gradients. However, most strategies for gradient casting require specialized apparatus and have high equipment requirements. Therefore, there is a strong desire to develop a simple method for constructing gradient scaffolds that mimic the hierarchical structure of native bone. In this study, we prepared poly (vinyl alcohol)/bacterial cellulose (PVA/BC) scaffolds with gradient hydroxyapatite (HAp) content using the buoyancy-driven gradient (BG) method. Scanning electron microscopy characterization revealed that HAp gradient scaffold exhibited the gradient microstructure and HAp content. Furthermore, HAp gradient scaffold demonstrated enhanced adhesion, spreading, and proliferation of MC3T3-E1 cells and displayed excellent osteogenic ability. Additionally, when applied in subcutaneous implantation models in mice, HAp gradient scaffold showed superior biocompatibility compared to other scaffolds tested in vitro. These results present a straightforward approach for fabricating gradient HAp bone scaffolds that hold great potential as candidate materials for bone regeneration.