Porous PLGA microspheres for the inhalation delivery of icariin and miR-23b in the treatment of metastatic lung cancer

Herein, porous poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared to load icariin and miR-23b for the treatment of metastatic lung cancer. The microspheres exhibited desirable aerodynamic diameter, high drug loading and encapsulation efficiency, as well as a favorable drug release profile, which was beneficial for the deposition and exposure of drugs in the lung tissues. The release solution from microspheres exhibited a favorable anti-proliferative effect by inducting cell apoptosis and arresting the cell cycle at G1 phase, and meanwhile inhibited the migration and invasion of cancer cells. More importantly, the microspheres could be effectively inhaled and accumulated in the lung tissues to trigger the <i>in situ</i> apoptosis of tumor cells and suppress metastasis, using mice bearing melanoma-metastatic lung cancer as a model. Furthermore, inhalation of the microspheres showed favorable biocompatibility, barely causing tissue damage. Overall, porous PLGA microspheres provide a promising platform for the inhalable co-delivery of drugs and genes to obtain ideal therapeutic efficacy in lung cancer and other pulmonary diseases.