Preparation of triplea??responsive porous silica carriers and carbon quantum dots for photodynamica??chemo therapy and cell multicolor imaging

摘要： Photosensitive carbon quantum dots (CQDs) provide a new route to treat cancer owing to their ability to produce singlet oxygen. In this paper, pH/redox/enzyme-responsive porous silica-based carriers with CQDs were constructed for photodynamic-chemical combination therapy. Porous silica (pSiO2) sample presents uniform sphere with center-radial channels, which is favorable for drug loading and delivery. The CQDs with size of 2.5 nm were synthesized and have the excellent ability to generate singlet oxygen. After loading CQDs and drug molecules, the channels of pSiO2 carrier were blocked with hyaluronic acid (HA)/chitosan (CHI) layer. The disulfide bonds conjugating HA to the surface of pSiO2 carrier would achieve redox-responsive drug release while breaking disulfide bonds and HA/CHI layer could endow the pSiO2 carrier enzyme/pH responsive drug release. The prepared pSiO2 carriers display low cytotoxicity and good biocompatibility for multicolor imaging and photodynamic-chemo therapy.