Protein and Peptide Inhibitors of Mineralization: A Systematic Review of in Vitro Studies.

Biomineralization is regulated by interactions between inorganic phases and biological macromolecules. Peptides derived from mineral-associated proteins are key modulators due to their ability to bind crystal nuclei and mineral surfaces. However, the molecular features governing peptide-mediated mineralization inhibition remain insufficiently synthesized in current research. This systematic review, conducted following PRISMA and Cochrane standards, evaluated in vitro evidence regarding the physicochemical properties and inhibitory mechanisms of protein- and peptide-based mineral modulators. Comprehensive searches in MEDLINE, LILACS, and Scopus (up to November 2025) identified fifty studies utilizing crystallization assays or mineralizing cell models. A dedicated risk-of-bias assessment tool, adapted from the RoB2 framework, was developed to evaluate methodological quality in in vitro studies. Although both proteins and peptides were investigated, many inhibitory molecules corresponded to peptides derived from proteins, particularly osteopontin and matrix Gla protein. Effective inhibitors shared common features, including enrichment in acidic residues, low isoelectric points (< 4.8), and posttranslational modifications such as phosphorylation. These properties significantly inhibit mineral nucleation and crystal growth, while reducing calcium deposition and alkaline phosphatase activity in cellular models. This review highlights sequence-dependent physicochemical determinants of peptide-mineral interactions and provides a framework for the rational design of peptide-based mineralization inhibitors.