A novel fluffy hydroxylapatite fiber scaffold with deep interconnected pores designed for three-dimensional cell culture.

Functional scaffolds that could mimic cells' natural growth state in vitro are crucial for meeting the requirements of complex biological systems. However, the compact macrostructure and poor cell survival macro-environment of biomaterials are still two major challenges limiting their practical applications in bone tissue regeneration. In this study, we fabricated a highly fluffy and porous biomineral hydroxylapatite (HA) encapsulated poly-l-lactic acid (PLLA) composite fibrous scaffold (fluffy-HAFSs) by employing an improved electrospinning technique combined with a bio-mineralization technique. In the scaffold, deep interconnected pores of 65 ± 35 μm formed among these fluffy HA fibers, which permitted the easy entry of cells into the fluffy-HAFSs with no extra help to achieve complicated 3D cell culture methodologies. Human mesenchymal stem cells (hMSCs) were seeded onto the composite fibrous scaffolds and cultured for 14 days in vitro. The morphology and biochemical activities of hMSCs were tested over the culture period. Evidence was provided for the hMSCs entry into the interior of the fluffy-HAFSs and achievement of 3D cell distribution. Furthermore, these hMSCs exhibited higher degrees of growth, osteogenic differentiation and mineralization than those on HA deposited traditional electrospun fibrous meshes (HAFMs). These results indicated that the novel fluffy-HAFSs might be potentially applied as bone repairing and regeneration scaffolds.