A VITA Index for predicting cytocompatibility of metallic biomaterials based on ion release and toxicity.

Abstract

Biocompatibility and cytocompatibility are critical early considerations in the development of metallic biomaterials for implantable devices; however, conventional in vitro cytotoxicity evaluations typically assess corrosion behavior or cytotoxicity independently and fail to account for their coupled effects on metal-ion release-driven cytocompatibility. Here, we present a novel Velocity-Ion Toxicity-Affinity (VITA) Index-a quantitative and mechanistically informed framework that integrates electrochemical dissolution (corrosion) behavior with ion-specific cytotoxicity to evaluate in vitro biocompatibility governed by metal-ion release. By combining corrosion profiling with cell-based cytocompatibility assays (using osteoblasts and fibroblasts as a representative model), the VITA Index demonstrates first-order accuracy, capturing robust correlations between ion-release kinetics and cell viability across both established biomedical alloys and emerging materials, including high-entropy alloys. The VITA Index enables rapid and mechanistically informed screening of candidate metallic biomaterials and provides a practical framework for in vitro biocompatibility assessment, cytotoxicity prediction, and data-driven alloy design for future implant applications.