Chitosan/hyaluronic acid based hollow microcapsules equipped with MXene/gold nanorods for synergistically enhanced near infrared responsive drug delivery.

Ti3C2 MXenes, a novel two-dimensional material, have attracted lots of attention in biomedical filed for its large surface area and excellent near-infrared (NIR) responsiveness. In this paper, a pH/near-infrared (NIR) multi-responsive drug delivery platform consisted of hollow hydroxyapatite (HAP), chitosan (CS)/hyaluronic acid (HA) multilayers, gold nanorods (AuNRs) and MXene had been fabricated via a layer-by-layer (LbL) approach. Chitosan/hyaluronic acid multilayers were deposited on the surface of hollow HAP to retard the burst release of DOX in the initial delivery stage. MXenes and AuNRs equipped on the surface of hybrid matrix greatly enhanced the photothermal conversion efficiency of the microcapsules. Due to the collapse of electrostatic force among chitosan/hyaluronic acid multilayers and the dissolution of HAP under acidic condition, as well as the synergistically enhanced photothermal effect between MXene and AuNRs, HAP/CS/HA/MXene/AuNRs microcapsules exhibited outstanding pH-/NIR-responsive drug delivery properties. The present paper provides an attractive method to prepare chitosan/hyaluronic acid based pH/NIR multi-responsive hybrid microcapsules with excellent photothermal conversion efficiency and biocompatibility, which has great potential in the field of remotely controlled drug delivery.