Intrafibrillar\nMineralized Collagen–Hydroxyapatite-Based\nScaffolds for Bone Regeneration

Abstract

As one of the major\nchallenges in the field of tissue engineering,\nlarge skeletal defects have attracted wide attention from researchers.\nCollagen (Col) and hydroxyapatite (HA), the most abundant protein\nand the main component in natural bone, respectively, are usually\nused as a biomimetic composite material in tissue engineering due\nto their excellent biocompatibility and biodegradability. In this\nstudy, novel intrafibrillar mineralized Col–HA-based scaffolds,\nconstructed in either cellular or lamellar microstructures, were established\nthrough a biomimetic method to enhance the new bone-regenerating capability\nof tissue engineering scaffolds. Moreover, iron (Fe) and manganese\n(Mn), two of the essential trace elements in the body, were successfully\nincorporated into the lamellar scaffold to further improve the osteoinductivity\nof these biomaterials. It was found that the lamellar scaffolds demonstrated\nbetter osteogenic abilities compared to both in-house and commercial\nCol–HA-based cellular scaffolds <i>in vitro</i> and <i>in vivo</i>. Meanwhile, Fe/Mn incorporation further amplified\nthe osteogenic promotion of the lamellar scaffolds. More importantly,\na synergistic effect was observed in the Fe and Mn dual-element-incorporated\nlamellar scaffolds for both <i>in vitro</i> osteogenic differentiation\nof bone marrow mesenchymal stem cells (BMSCs) and <i>in vivo</i> bone regeneration loaded with fresh bone marrow cells. This study\nprovides a simple but practical strategy for the creation of functional\nscaffolds for bone regeneration.