Limitation of Water-Soluble Tetrazolium Salt for the Cytocompatibility Evaluation of Zinc-Based Metals.

Peijun Zhu,Shulan Xu,Jiahao Chen,Ping Li

doi:10.3390/ma14216247

Abstract

Zinc (Zn) and its alloys have been regarded as promising biodegradable metals. The standardized cytotoxicity evaluation is a mandatory step to screen the biocompatibility of novel Zn and its alloys. Nevertheless, the suitability of the tetrazolium-based assay in the direct contact test for some metallic biomaterials (i.e., magnesium and manganese) is questionable. In this study, our results demonstrate an obvious inconsistency between qualitative observation via fluorescence staining and quantitative assessment using water-soluble tetrazolium salt (CCK-8). Subsequent experiments revealed that Zn and pre-treated Zn can directly convert tetrazolium salts to formazan, falsifying the cytotoxicity results. Therefore, we conclude that the CCK-8 assay is not suitable for evaluating the cytotoxicity of biodegradable Zn-based metals in the direct contact test.

Highlights

Biodegradable metals (BMs) have been considered as promising implant materials especially for oral and maxillofacial applications, such as osteosynthesis implant and guided bone membrane, etc
The aim of this study was to investigate the suitability of a tetrazolium-based assay for the in vitro cytotoxicity evaluation of biodegradable zinc-based materials via a direct contact test
To clarify the possible interference between Zn and CCK-8 assays, we explored whether the Zn and P-Zn samples react with the CCK-8 assay

Summary

Introduction

Biodegradable metals (BMs) have been considered as promising implant materials especially for oral and maxillofacial applications, such as osteosynthesis implant and guided bone membrane, etc. BMs refers to metallic materials that degrade safely and gradually within the human body [1,2,3]. Mg-based implant materials have been widely investigated and even used in clinical trials [1,3]. Regarding the issue of Mg biodegradation, the rapid degradation rate accompanied by the accumulation of hydrogen of Mg-based materials could impede tissue healing and remodeling [4,5]. Fe-based implant materials within bony environments exhibit relatively slow degradation behavior, especially for the formation of insoluble degradation products, which adversely affects tissue remodeling [6,7]

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