Catalytic core–shell nanoparticles with self-supplied calcium and H(2)O(2) to enable combinational tumor inhibition

Nanoparticles, presenting catalytic activity to induce intracellular oxidative species, have been extensively explored for tumor treatment, but suffer daunting challenges in the limited intracellular H(2)O(2) and thus suppressed therapeutic efficacy. Here in this study, a type of composite nanoparticles, consisting CaO(2) core and Co-ferrocene shell, is designed and synthesized for combinational tumor treatment. The findings indicate that CaO(2) core can be hydrolyzed to produce large amounts of H(2)O(2) and calcium ions at the acidic tumor sites. Meanwhile, Co-ferrocene shell acts as an excellent Fenton catalyst, inducing considerable ROS generation following its reaction with H(2)O(2). Excessive cellular oxidative stress triggers agitated calcium accumulation in addition to the calcium ions released from the particles. The combined effect of intracellular ROS and calcium overload causes significant tumor inhibition both in vitro and in vivo. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12951-021-01055-4.