Star-Shaped Multivalent Molecular Scavengers for Neutrophil Extracellular Trap-Associated Chromatin Neutralization and Sepsis Treatment

Abstract Extracellular chromatin is a composite DNA–protein assembly that is difficult to recognize selectively using conventional cationic nucleic acid scavengers. Inspired by the spatially organized recognition of biomacromolecular assemblies, we developed a library of valency-programmed poly(ethylene glycol)-aminoglycoside conjugates that preferentially recognize neutrophil extracellular trap (NET)–associated chromatin while retaining antibacterial activity. Screening aminoglycoside identity and scaffold valency identified 8-arm poly(ethylene glycol)-netilmicin (8-arm Netil) as the lead construct. Its flexible multivalent architecture enabled simultaneous contacts with DNA phosphates and histone-associated sites, generating cooperative electrostatic and hydrogen-bonding interactions. At equal netilmicin equivalents, 8-arm Netil retained stronger chromatin binding than free netilmicin and the 2- and 4-arm conjugates, whereas cationic poly(amidoamine) dendrimers failed to reproduce its combined affinity and selectivity. 8-arm Netil bound DNA–histone chromatin with a dissociation constant of 5.73 × 10–8 M, and showed substantially weaker interactions with isolated DNA, histones, and serum albumin. This multivalent recognition suppressed NET-induced Toll-like receptor 4 and 9 signaling while preserving antibacterial activity. In bacterial peritonitis and polymicrobial sepsis models, 8-arm Netil reduced bacterial dissemination, extracellular chromatin burden, inflammation, and mortality. This work establishes valency-programmed aminoglycoside presentation as a chemical strategy for recognizing and neutralizing composite extracellular chromatin.