Hierarchical Assembly of Flexible Biopolymer Polyphosphate‐Manganese into Nanosheets

Polyphosphate (polyP) is one of the most compact inorganic polyanionic biopolymers that participates in various physiological processes. However, the development of polyP‐based nanomaterials is still in its infancy. Here, biocompatible polyphosphate‐manganese nanosheets are designed and synthesized by a hierarchical assembly strategy. The thickness and the lateral size of the resulting polyP‐Mn nanosheets (PMNSs) are 5 nm and 120–130 nm, respectively. Molecular dynamics simulations suggested that the polyP‐hexadecyl trimethyl ammonium bromide flat structure possesses a strong aggregating capacity and serves as the template for the 2D assembly of polyP‐Mn. The PMNSs can activate the inflammatory response of macrophages resulting in the recovery of innate immunological functions to inhibit tumor proliferation. This work has initiated a new direction in constructing layered polyP‐based nanomaterials and provides guidance for biocompatible and biodegradable biopolymer‐based materials in the regulation of innate responses. Here, polyP‐Mn nanosheets (PMNSs) are synthesized by a hierarchical assembly strategy. Hexadecyl trimethyl ammonium bromide and oleate ions act as indispensable structure‐directing reagent in the formation of PMNSs. Besides, molecular dynamics simulations are performed for a deeper understanding of the assembly process. Subsequent experiments suggested that PMNSs induce inflammatory responses to activate the innate immune response of macrophages and suppress 4T1 cancer cell growth.