Tailor-made poly-γ-glutamic acid for property diversity and biological function

Poly-γ-glutamic acid (γ-PGA) is a versatile biodegradable polymer with extensive industrial applications, where its functionality is influenced by structural properties. Tailor-made γ-PGA has accordingly emerged to satisfy the growing demand for specialized applications. This review examines the diverse industrial applications of γ-PGA, focusing on variations in molecular weight and stereochemical configurations, thereby elucidating the fundamental principle that "structure dictates function". Subsequently, it highlights recent advancements in metabolic engineering strategies designed to precisely control the molecular weight and stereochemistry of γ-PGA. Furthermore, this review prospectively proposes the potential of cell-free systems as an innovative platform for the efficient, flexible, and on-demand production of tailored γ-PGA, addressing the limitations inherent in traditional cellular systems. This review seeks to provide theoretical insights for the future rational design and precise synthesis of a new generation of γ-PGA with targeted functional properties.