Versatile metal-phenolic network structure (MPNs) as advanced delivery platforms for bioactive compounds: The design principles, foundations, applications, and future perspectives

Despite possessing many important functions, the applications of bioactive compounds (BCs) are significantly limited due to various inherent shortcomings. In recent years, a novel class of materials known as metal-phenolic network structures (MPNs) has emerged. As the application scope of MPNs expands, it has become evident that this network structure can protect encapsulated active substances from adverse external environmental influences. This review first introduces the types and properties of polyphenols and metal ions, as well as the basis of their interactions. Subsequently, the construction methods of MPNs and their advantages as delivery platforms for BCs are discussed, including stimuli-responsive properties, adsorption properties, UV resistance, antioxidant activity, and antimicrobial effects. The mechanisms involved in the loading of BCs into MPNs and their novel applications in nanoparticles, films, coatings, capsules, emulsions, and hydrogels are elucidated. Additionally, the safety of MPNs and their fate within the human body are addressed. The role of artificial intelligence in advancing the development of MPNs as delivery platforms for BCs is also described in detail. Finally, the advantages, limitations, and obstacles to the clinical transformation of MPNs as delivery platforms are discussed. This review aims to uncover the significant role of MPNs in delivering BCs, thereby promoting the development of MPNs and the broader application of BCs.