Autofluorescent and pH-responsive mesoporous silica for cancer-targeted and controlled drug release

• A new autofluorescent and pH-sensitive multifunctional drug release system developed.
• Mesoporous silica composite formed by layer-by-layer assembly for cell tracing.
• The nanocarriers are FA-targeting and pH-responsive release of the loaded drug.

A new autofluorescent and pH-sensitive multifunctional drug release system is developed in this contribution by layer-by-layer assembly of chitosan (CHI)/dialdehyde starch (DAS) polyelectrolyte multilayers (PEM) onto mesoporous silica nanoparticles (MSN) surface. The formed mesoporous silica composites can be used as drug delivery carriers, which have very slow drug release rate at pH 7.4, but have very fast drug release rate at pH 5.0 owing to the breakage of CN bonds of the CHI/DAS multilayers under acidic condition. As a proof of concept, folic acid (FA) has been conjugated to the outer surface of the mesoporous silica composites by the amide reaction in order to deliver target anticancer drug, and it is found that cellular uptake of the folate conjugated doxorubicin-loaded nanoparticles in folate receptor-overexpressing HeLa cells is much higher than that of non-folate receptor-overexpressing A549 cells, indicating that successful targeting drug release has realized.

Mesoporous silica nanoparticles (MSN) have attracted increasing interest as drug delivery vehicles due to high surface area, pore volume, and biocompatibility. In order to trace into cell, mesoporous silica hybrid materials use quantum dots (QDs) or dyes for cell tracing. To avoid the use of QDs or dyes for cell tracing, an autofluorescent mesoporous silica composite are formed by layer-by-layer assembly. The formed hybrid materials possesss properties of FA-targeting, pH-responsive release of the loaded drug and cell imaging.Figure optionsDownload as PowerPoint slide