# Calcium Phosphates for Bone Tissue Regeneration—Influence of Synthesis Method on Physicochemical and Biological Properties

## TL;DR

This study shows how different ways of making calcium phosphate materials affect their properties and suitability for bone regeneration.

## Contribution

The study demonstrates how synthesis methods and pH control influence physicochemical and biological properties of calcium phosphates.

## Key findings

- Synthesis method and pH significantly affect phase composition, particle size, and Ca/P ratio.
- Materials show good biological tolerance and no cytotoxic effects on fibroblasts and osteoblasts.
- Proper synthesis allows control of material properties for bone tissue engineering applications.

## Abstract

Calcium phosphates, including hydroxyapatite, are widely used biomaterials in bone tissue regeneration due to their bioactivity, osteoconductivity, and similarity to the mineral phase of bone. In this study, various apatite calcium phosphate powders were synthesized using three precipitation methods, with controlled pH conditions and reagent ratios, to assess the effect of the synthesis method on their physicochemical and biological properties. Elemental composition (Ca/P ratio), FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with EDS, and particle size measurements were used to determine the structure, morphology, and stoichiometry of the obtained powders. The results indicated that the synthesis method and pH significantly affect the phase composition of the material, particle size, and Ca/P ratio, which directly influence their solubility and bioactivity. Microbiological tests, NF-κB transcription factor activation, metabolic activity, and cell compatibility of mouse L929 fibroblasts and human hFOB 1.19 osteoblasts showed good biological tolerance of the obtained powders and no cytotoxic effects. The results confirm that a properly selected synthesis method allows for the control of material properties, which is crucial for applications in bone tissue engineering. The materials show potential for use as bioactive components in bone-related biomaterials.