MY-1 Loaded Nano-Hydroxyapatite Accelerated Bone Regeneration by Increasing Type III Collagen Deposition in Early-stage ECM via a Hsp47 Dependent Mechanism.

The extracellular matrix (ECM) plays a crucial part in regulating stem cell function through its distinctive mechanical and chemical effect. Therefore, it is worth studying how to activate the driving force of osteoblast cells by dynamic changing of ECM and accelerate the bone regeneration. In the present research, a novel osteogenic short peptide MY-1 was designed and synthesized. To extend its releasing period and strengthening activation effect, the nano-hydroxyapatite is chosen as the carrier of MY-1 by mixed adsorption (nHA/MY-1). The results reveal that nHA/MY-1 could extend the releasing period to more than two weeks. The sustainable releasing of MY-1 regulates the synthesis and secretion of ECM from rat bone marrow mesenchymal stem cells (rBMSCs), which promotes the cell migration and osteogenic differentiation in the early stage of bone regeneration. Further analyses demonstrate that MY-1 increases the expression and nuclear translocation of β-catenin, and then upregulates the level of protein Hsp47, thereby accelerating the synthesis and secretion of type III collagen (Col III) at the early stage. Finally, the promoted rapid transformation of Col III to Col I at late stage benefits the bone regeneration. Hence, this study can provide a theoretical basis for the local application of MY-1 in bone regeneration. This article is protected by copyright. All rights reserved.