Nanoscale Hf-hematoporphyrin frameworks for synergetic sonodynamic/radiation therapy of deep-seated tumors

Most of tumors are located in deep-depth of animals, and the therapy of deep-seated tumors remains a severe challenge due to the performance reduction of promising technologies including phototherapy. To solve the problem, herein we have developed a hafnium-hemoporfin frameworks (HfHFs) as multifunctional theranostic nanoplatforms for synergetic sonodynamic therapy (SDT) and radiation therapy (RT) of deep-seated tumors. HfHFs are constructed by a sonication-assisted assembly route with hematoporphyrin monomethyl ether (HMME) sonosensitizer molecules as bridging linkers and Hf⁴⁺ as metal nodes. The resulting HfHFs sample is composed of spherical nanoparticles with size of 90-130 nm, and then surface-modified with DSPE-PEG to improve the water-dispersity. Under ultrasound (US) irradiation, HMME ligands in HfHFs can be motivated to produce singlet oxygen (¹O₂) due to sonodynamic effect. When the HfHFs sample is exposed by X-ray, the high atomic-number Hf⁴⁺ in the HfHFs can effectively absorb X-ray to increase RT effect by producing hydroxyl radicals (•OH). When HfHFs dispersion is intravenously injected in the tumor-bearing mice, the tumor can be monitored by CT imaging. Moreover, the deep-seated tumors coated by tissue barriers can be suppressed effectively by the synergistic SDT and RT, which is better than that of SDT or RT alone. Therefore, HfHFs can be employed as a novel nanoagent for the SDT-RT of deep-seated tumors.