Rational designing of an antidote nanoparticle decorated with abiotic polymer ligands for capturing and neutralizing target toxins.

Many of macromolecular toxins induce cell death by directly interacting with cells or induction of inflammatory cytokines. Abiotic polymer ligands (PLs) composed of functional monomers are able to bind and neutralize toxins in vivo and are of great interest for efficient antidotes. However, little has been reported about recognition and neutralization of target molecules in the bloodstream because of readily elimination from the bloodstream. Here, we report a rational design of PLs-decorated lipid nanoparticles (PL-NPs) for neutralizing a target toxin in vivo. PL that decorated on the NPs would cooperatively interacts with target biomacromolecules since the lipid molecules in NPs have a high degree of freedom. In the present study, N-isopropylacrylamide based PLs interacting with histones, major mediators of sepsis, were synthesized. Affinity between PL-NPs and histones depends on monomer composition and polymer length. The optimized PL-NP showed little affinity for plasma proteins. The PL-NPs inhibited the toxicity of histones both in vitro and in vivo, suggesting that PLs on the NPs cooperatively bound to histones and neutralized their toxicity. In addition, circulation time of optimized PL was significantly prolonged by the modification onto NPs. These results provide a platform for designing antidote nanoparticles neutralizing toxic biomacromolecules.