Bio-inspired bioactive glasses for efficient microRNA and drug delivery

Bio-inspired pinecone-like bioactive glasses consisting of ordered thin-layers separated by consistent cavities were synthesized using a sol-gel process. The short diameter of the as-produced particles was as short as 161 nm, and the surface area was as high as 280 m² g^-1. The pore volume, ranging from ∼0.74 cm³ g^-1 to ∼0.67 cm³ g^-1, could be modulated by the aqueous ammonia concentration. The surface was further tailored for positive charges by amino grafting. The as-produced nanoparticles could successfully enter cells via endocytosis. The microRNA delivery of the bioactive glass particles was further investigated by fluorescence microscopy and flow cytometry, indicating a loading efficiency and transfection efficiency greater than 90%. The potential of such particles as drug carriers was also studied. CCK8, live-dead cell staining and PI/annexinV double staining analyses confirmed that the bioactive glass particles loaded with antitumour doxorubicin (DOX) significantly accelerated the apoptosis of tumour cells. These bio-inspired bioactive glasses are promising as novel vectors for drug and microRNA delivery with high efficiency.