Intracellular pH-Triggered, Targeted Drug Delivery to Cancer Cells by Multifunctional Envelope-Type Mesoporous Silica Nanocontainers

In this work, a novel type of pH-sensitive multifunctional envelope-type mesoporous silica nanocontainers (SBDAPF) was constructed for targeted drug delivery to cancer cells. Poly(N-succinimidyl acrylate) was coated on the mesoporous silica nanoparticles surface via an acid-labile acetal linker to obtain the SBA particles for pH-triggered drug release. A model drug doxorubicin (DOX)-loaded SBA system (SBDA) showed low premature drug release at neutral pH and effective stimuli-responsive release under the acidic conditions. To provide the colloidal stability and avoid nonspecific uptake of normal or healthy cells, the SBDA nanocontainers were modified with a poly(ethylene glycol) (PEG) polymer to form a protection layer. Furthermore, folic acid was introduced as a targeting component and anchored on the PEG outer layer to achieve the cancer-targeting ability. In vitro study demonstrated that SBDAPF could selectively adhere to the surface of cancer cells through the specific binding with folate receptor and...