Preparation and characterization of a pH-responsive mesoporous silica nanoparticle dual-modified with biopolymers

This study was aimed at preparing a highly dispersed and pH-sensitive mesoporous silica nanoparticles (MSNs) carrier via surface modification with polydopamine (PDA) and polyethylene glycol (PEG) i.e. MSNs@PDA-PEG. Small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) measurements suggested that hexagonally structured MSNs (type MCM-41) with the layer of PDA and PEG of thickness similar to 20 nm were successfully prepared. Bovine serum protein (BSA) adsorption experiments showed that less protein was absorbed by MSNs@PDA-PEG after the anchoring of PEG, which confirmed the stealth properties of prepared carriers. Doxorubicin hydrochloride (DOX) was used as the model drug to be encapsulated into MSNs@PDA-PEG (DOX/MSNs@PDA-PEG). The DOX/MSNs@PDA-PEG had relatively high entrapment efficiency and drug loading up to 94.2% and 31.4%, respectively. The in vitro release profile of DOX/MSNs@PDA-PEG exhibited pH-responsive and gradual drug release. Cytotoxicity assay showed that DOX/MSNs@PDA-PEG had comparable cytotoxicity to A549 cells compared to pure DOX. The intracellular distribution of DOX/MSNs@PDA-PEG was imaged using confocal laser scanning microscope. It points that PDA and PEG can play gatekeeper and stealth roles for MSNs as promising nanocarrier for cancer treatment.