pH-responsive mesoporous silica drug delivery system for targeted cancer chemotherapy

In this paper, a kind of pH-responsive mesoporous silica targeted drug delivery system (DOX-loaded N-CQDs/HA gated pSiO2/MPEG-Glu) was designed and synthesised. In this system, active mesoporous silica (pSiO2) worked as a carrier material, methoxy polyethene glycol amine (MPEG) and L-glutamic acid (Glu) can be coupled and grafted to the surface of the pSiO2 drug carrier to improve the stability of the drug delivery system, nitrogen-doped carbon quantum dots (N-CQDs) and hyaluronic acid (HA) can inhibit the rapid release of drug. Ultraviolet (UV-Vis) spectrum showed that the drug-loading rate of DOX is 8.9%, the drug release in vitro study suggested that the prepared silica drug delivery system had significant pH-responsive and targeted DOX release, the drug release rate is 55.7% at pH = 5.0, which was much higher than the release of pH = 7.4; CLSM and MTT showed that the drug delivery system can enter into cancer cells through endocytosis and the DOX can act on cell nucleus, exhibiting a targeted therapy on cancer cells.