A thermostability perspective on enhancing physicochemical and cytological characteristics of octacalcium phosphate by doping iron and strontium

Abstract

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.

Zn/Sr dual ions-collagen co-assembly hydroxyapatite enhances bone regeneration through procedural osteo-immunomodulation and osteogenesis

“…Various methods have emerged to improve the hydroxyapatite-based materials’ biological performance, such as element doping, heat treatment, material cladding, etc. [ [13] , [14] , [15] ]. Among these, inorganic ion doping is an important strategy for modifying hydroxyapatite-based materials because the substituted ions have a crucial influence on the structure, composition, and mechanical properties of the mineral phase.…”

Comparison of bovine serum albumin and chitosan effects on calcium phosphate formation in the presence of silver nanoparticles

“…The second loss of 4.0% in the temperature range 172-495 °C corresponds to CaP decomposition. 79,80 The thermal decomposition of BSA proceeds in 4 steps. In the temperature range 75-150 °C the weight loss of 3.5% could be ascribed to the evaporation of adsorbed water.…”

Surface Functionalization of Hydroxyapatite Scaffolds with MgAlEu‐LDH Nanosheets for High‐Performance Bone Regeneration

“…[ 16 , 17 ] To this end, various methods have been developed to enhance the bioactivity and cell crawling/adhesion properties of HAp scaffolds, such as creating porous surface via 3D printing [ 18 , 19 , 20 ] or surface modification to promote the cell adhesion and differentiation, [ 21 , 22 , 23 , 24 ] and doping or surface modification with bioactive elements to improve the bioactivity of HAp scaffold. [ 25 , 26 , 27 ] For example, reduced graphene oxide (rGO) has been used to modify the surface of porous HAp to prepare 3D porous HAp/rGO scaffolds with a hierarchical structure. [ 17 ] The loaded rGO can improve the adhesion and promote the spontaneous osteogenic differentiation and proliferation of bone marrow mesenchymal stem cells (BMSCs).…”