Fig. 2: X-ray rescues the activity of oxygen atom-engineered immune agonist prodrugs.

a Schematic illustrations of the e^-_aq generated from water radiolysis induces the release of R848 from O-R848 through deoxygenation reaction. b Radiation dose-dependent release of R848 from O-R848 (10 μM in PBS solution) detected by UPLC-MS. c Time-dependent release of R848 from O-R848 (10 μM in PBS solution) irradiated by 60 Gy X-ray detected by UPLC-MS. d Synthesized oxygen atom-engineered immune agonist prodrugs have been assayed for X-ray-induced deoxygenation reaction and immunostimulatory activity rescuing. e Molecular orbitals of prodrug (O-R848 as a model compound that indicate e^-_aq is captured by the π-system of imidazoquinoline group). f |ΔG| between the anion radical intermediate after capturing e^-_aq and the ground state of prodrugs compared with |ΔG| of e^-_aq. g Activation yields of agonists from corresponding prodrugs (10 μM in PBS solution) irradiated by 60 Gy X-ray (n = 3 independently tested samples for each group). h Concentration-dependent TLR7/8 activation curves of active agonists, and corresponding prodrugs without and with 60 Gy X-ray irradiated. Data were assessed in RAW-Blue report cells after 24 h incubation (n = 6 independently tested cell samples for each group), presented as mean values ± s.d. Source data are provided as a Source Data file.