Construction of a pH-responsive drug delivery platform based on the hybrid of mesoporous silica and chitosan

Mesoporous silica nanoparticles (MSN) have been widely used for drug delivery due to their large specific surface area and excellent biocompatibility. However, the mesoporous structure of MSN would lead to the inevitable premature release of the drugs, and therefore the modification of MSN for controlled delivery seems to be a necessary step. Herein, chitosan (CS) was used for the surface functionalization of MSN via amidation reaction, and the introduced CS could function as a gatekeeper and the drug of methotrexate (MTX) might be encapsulated in the mesopores of MSN. As a result, the premature release of the encapsulated MTX could be effectively circumvented with the aid of the CS cap. More importantly, the drug delivery from the hybrid of MSN and CS (MSN/CS) can be endowed with pH-sensitivity by the introduction of CS because the amide bonding between CS and MSN is highly pH-sensitive. The cumulative release of MTX from the MSN/CS is more pronounced at pH 5.0 (80.86%) than those at pH 6.8 (40.46%) and pH 7.4 (18.25%). (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

In this study, chitosan (CS) was used for surface functionalization of mesoporous silica nanoparticles (MSN) to form a hybrid of MSN and CS (MSN/CS) for controlled drug delivery with pH-sensitivity. The introduced CS acted as a gatekeeper to prevent premature drug release, leading to higher cumulative release rates, especially at pH 5.0.