Carbon Free Radical (R⋅) Inactivates NF‐κB for Radical Capping Therapy

Abstract Inactivating hyperactivated transcription factors can overcome tumor therapy resistance, but their undruggable features limit the development of conventional inhibitors. Here, we report that carbon‐centered free radicals (R⋅) can inactivate NF‐κB transcription by capping the active sites in both NF‐κB and DNA. We construct a type of thermosensitive R⋅ initiator loaded amphiphilic nano‐micelles to facilitate intracellular delivery of R⋅. At a temperature of 43 °C, the generated R⋅ engage in electrophilic radical addition towards double bonds in nucleotide bases, and simultaneously cap the sulfhydryl residues in NF‐κB through radical chain reaction. As a result, both NF‐κB nuclear translocation and NF‐κB‐DNA binding are suppressed, leading to a remarkable NF‐κB inhibition of up to 94.1 %. We have further applied R⋅ micelles in a clinical radiofrequency ablation tumor therapy model, showing remarkable NF‐κB inactivation and consequently tumor metastasis inhibition. Radical capping strategy not only provides a method to solve the heat‐sink effect in clinic tumor hyperthermia, but also suggests a new perspective for controllable modification of biomacromolecules in cancer therapy.