Synthesis and characterization of biomimetic bioceramic nanoparticles with optimized physicochemical properties for bone tissue engineering

Calcium phosphate bioceramics nanoparticles such as nano-hydroxyapatite (nHA) and nano-tricalcium phosphate (nTCP) are the main focus of basic and applied research for bone tissue regeneration. In particular, a combination of these two phases (nHA + nTCP) which refers to as "nano-biphasic calcium phosphates (nBCP)" is of interest due to the preferred biodegradation nature compared to single-phase bioceramics. However, the available synthesis processes are challenging and the biomaterials properties are yet to be optimized to mimic the physiochemical properties of the natural nanoscale bone apatite. In this study, a new approach was developed for the production of optimized bioceramic nanoparticles aiming to improve their biomimecity for better biological performances. Nanoparticles were synthesized through a carefully controlled and modified wet mechano-chemical method combined with a controlled solid-state synthesis. Different processing variables have been analyzed including; milling parameters, post-synthesis treatment, and calcination phase. Detailed physicochemical characterizations of nanoparticles revealed higher crystallinity (∼100%), lower crystallite/particle size (58 nm), higher homogeneity, reduced particle agglomeration size (6 μm), and a closer molar ratio (1.8) to biological apatite compared to control and standard samples. Furthermore, the study group was confirmed as calcium-deficient carbonate-substituted BCP nanoparticles (nHA/nβ-TCP: 92/8%). As such, the introduced method can afford an easier and accurate control over nanoparticle physiochemical properties including the composition phase which can be used for better customization of biomaterials for clinical applications. The findings of this article will also help researchers in the further advancement of production strategies of biomaterials. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1654-1666, 2019.