Three Birds with One Stone: Injectable CaC₂ Nanobombs with Triple Effects for Minimally Invasive Tumor Chemical...

Percutaneous chemical ablation (PCA) is the oldest and most established technique for treating small solid tumors in organs. It has been widely used in clinics even on an outpatient basis. However, compared with the emerging microwave or magnetic hyperthermal ablation, PCA is faced with relatively poor necrosis results and needs to repeat multiple sessions. Inspired by the three effects in the bomb's explosive process, we herein expect to combine calcium carbide (CaC₂) nanoparticles into the PCA technique to generate local explosion within tumor tissues, leading to three killing effects against tumors to further improve the ablation efficacy of PCA. Through an efficient wet milling procedure with poly(ethylene glycol), three kinds of nanobombs including CaC₂, calcium oxide (CaO), and calcium hydroxide (Ca(OH)₂) were fabricated, and they all exhibited desirable suspension stability. Among these nanobombs, in particular CaC₂ nanobombs showed a synergistic effect that the generation of ethyne gas bubbles could facilitate the most rapid diffusion of hyperthermia. Also, CaC₂ nanobombs offered the powerful ability to cause the sudden rise of local high temperature and pH value. According to the in vivo mice tumor excision trial, the tumors of 75% of cases that received CaC₂ treatment were destroyed and eradicated, exhibiting the excellent ablation ability of CaC₂ nanobombs against small solid tumors planted in mice.