Comprehensive Toxicological Evaluation of 3D-Printed Hydroxyapatite (3DPHA) for Bone Grafting Applications

TL;DR

This study confirms that 3D-printed hydroxyapatite is chemically pure and biologically safe for use in bone grafting.

Contribution

The paper provides the first comprehensive toxicological and compositional validation of 3DPHA for clinical use.

Findings

3DPHA showed phase-pure hydroxyapatite with a non-stoichiometric Ca/P ratio and low trace impurities.

In vitro tests found no cytotoxic, irritant, sensitizing, or mutagenic effects of 3DPHA.

The material complies with international benchmarks and is ready for clinical translation.

Abstract

Binder jet 3D printing combined with a low-temperature phase transformation process has emerged as a promising route for producing 3D-printed hydroxyapatite (3DPHA) scaffolds with controlled architecture for bone grafting applications. However, the toxicological profile of this unique binder jet-derived material has not yet been established. In this study, we conducted a comprehensive compositional and toxicological assessment of 3DPHA fabricated via the calcium sulfate transformation route. The material exhibited phase-pure hydroxyapatite (HA) with a Ca/P ratio consistent with non-stoichiometric HA and low levels of trace elemental impurities. In vitro assays revealed no cytotoxic, irritant, sensitizing, or mutagenic effects. This work provides a standardized toxicological and compositional safety validation of 3DPHA. By linking compositional purity to biological safety and demonstrating compliance with international benchmarks, this study establishes a regulatory foundation confirming that 3DPHA is chemically pure, biologically safe, and ready for clinical translation as a bone-graft material.

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