Polydopamine-based surface modification of mesoporous silica nanoparticles as pH-sensitive drug delivery vehicles for cancer therapy

A novel pH-sensitive drug delivery system of mesoporous silica nanoparticles (MSNs) which were modified by polydopamine (PDA) for controlled release of cationic amphiphilic drug desipramine (DES) was prepared. MSNs–DES–PDA were characterized in terms of size, size distribution, surface morphology, BET surface area, mesoporous size and pore volume, drug loading content and in vitro drug release profile. MSNs–DES–PDA had high drug loading content and pH sensitivity. The DES release profiles of MSNs–DES and MSNs–DES–PDA were totally different, and the drug release of MSNs–DES–PDA accelerated with increasing acidity. MSNs–DES–PDA can be internalized into cells. In vitro experiments demonstrated that MSNs–DES–PDA had higher cytotoxicity and inhibitory effects on acid sphingomyelinase than those of free DES. This drug delivery system was beneficial for controlled release and cancer therapy.