摘要
Investigation of thermostability will lead the groundbreaking of unraveling the mechanism of influence of ion-doping on the properties of calcium phosphates.In this work,octacalcium phosphate(OCP),a metastable precursor of biological apatite,was used as a stability model for doping ions(Fe^(3+)and Sr^(2+))with different ionic charges and radii.After treated under hot air at different temperatures(110-200◦C),the phase,morphology,structure,physicochemical properties,protein affinity,ions release,and cytological responses of the ion-doped OCPs were investigated comparatively.The results showed that the collapse of OCP crystals gradually occurred,accompanying with the dehydration of hydrated layers and the disintegration of plate-like crystals as the temperature increased.The collapsed crystals still retained the typical properties of OCP and the potential of conversion into hydroxyapatite.Compared to the undoped OCP,Fe-OCP,and Sr-OCP had lower and higher thermostability respectively,leading to different material surface properties and ions release.The adjusted thermostability of Fe-OCP and Sr-OCP significantly enhanced the adsorption of proteins(BSA and LSZ)and the cytological behavior(adhesion,spreading,proliferation,and osteogenic differentiation)of bone marrow mesenchymal stem cells to a varying extent under the synergistic effects of corresponding surface characteristics and early active ions release.This work paves the way for understanding the modification mechanism of calcium phosphates utilizing ion doping strategy and developing bioactive OCP-based materials for tissue repair.
基金
supported by the National Natural Science Foundation of China(Grant 31800791)
the Natural Science Foundation of Guangdong Province(Grant 2018030310062)
the Fundamental Research Funds for the Central Universities(Grant 21620427).
