Piezoelectric amino acids and peptides: Mechanisms, molecular engineering, and biomedical applications.

Piezoelectric amino acids and peptides have attracted growing attention in biomedical research because of their intrinsic piezoelectricity, superior biocompatibility, and biodegradability. The electrical signals generated by these materials resemble endogenous bioelectric signals in tissues, making them promising for biosensing, tissue regeneration, antimicrobial therapy, and cancer treatment. This review summarizes the piezoelectric mechanisms, classifications, molecular modification approaches, external-field-assisted fabrication methods, and reported biomedical applications of amino acid- and peptide-based piezoelectric biomaterials. It also outlines key challenges and future directions for biodegradable bioelectronic systems. By integrating these aspects, this review provides a theoretical foundation for developing targeted piezoelectric amino acid and peptide materials with excellent piezoelectric performance, biocompatibility, and biodegradability, and for promoting their clinical application.