Inhaled curcumin mesoporous polydopamine nanoparticles against radiation pneumonitis

Radiation therapy is an effective method to kill cancer cells and shrink tumors using highenergy X-ray or γ-ray. Radiation pneumonitis(RP) is one of the most serious complications of radiation therapy for thoracic cancers, commonly leading to serious respiratory distress and poor prognosis. Here,we prepared curcumin-loaded mesoporous polydopamine nanoparticles(CMPN) for prevention and treatment of RP by pulmonary delivery. Mesoporous polydopamine nanoparticles(MPDA) were successfully synthesized with an emulsion-induced interface polymerization method and curcumin was loaded in MPDA via π-π stacking and hydrogen bonding interaction. MPDA owned the uniform spherical morphology with numerous mesopores that disappeared after loading curcumin. More than 80% curcumin released from CMPN in 6 h and mesopores recovered. CMPN remarkably protected BEAS-2 B cells from γ-ray radiation injury by inhibiting apoptosis. RP rat models were established after a single dose of15 Gy^(60)Co γ-ray radiation was performed on the chest area. Effective therapy of RP was achieved by intratracheal administration of CMPN due to free radical scavenging and anti-oxidation ability, and reduced proinflammatory cytokines, high superoxide dismutase, decreased malondialdehyde, and alleviated lung tissue damages were observed. Inhaled CMPN paves a new avenue for the treatment of RP.