Intrafibrillar mineralization and immunomodulatory for synergetic enhancement of bone regeneration via calcium phosphate nanocluster scaffold.

Inspired by the bionic mineralization theory, organic-inorganic composites with hydroxyapatite nanorods orderly arranged along collagen fibrils have attracted extensive attention. Planted with an ideal bone scaffold will contribute greatly to the osteogenic microenvironment; however, it remains challenging to develop a biomimetic scaffold with the ability to promote intrafibrillar mineralization and simultaneous regulation of immune microenvironment in situ. To overcome these challenges, a scaffold containing ultra-small particle size calcium phosphate nanocluster (UsCCP) was prepared, which could enhance bone regeneration through the synergetic effect of intrafibrillar mineralization and immunomodulatory. By efficient infiltration into collagen fibrils, the UsCCP released from the scaffold achieved intrafibrillar mineralization. It also promoted the M2 type polarization of macrophages, leading to an immune microenvironment with both osteogenic and angiogenic potential. The results confirmed that the UsCCP scaffold had both intrafibrillar mineralization and immunomodulatory effects, making it a promising candidate for bone regeneration. This article is protected by copyright. All rights reserved.