Tumour development is not only an independent event of genetic mutation and overgrowth of tumour cells but is the result of a synergistic interaction between a malignant tumour and its surrounding tumour stromal microenvironment. In this paper, we address the shortcomings of current tumour therapy by focussing on the tumour itself and the surrounding microenvironment to achieve a two-pronged targeting model. In this paper, a dual-targeting, pH/reactive oxygen species (ROS) sensitive nano-drug delivery system for tumour cells and CAFs was designed. A hyaluronic acid (HA) with CD44 receptor targeting on the surface of tumour cells was selected as the main carrier material, and a dipeptide Z-glycine-proline (ZGP) with specific targeting of fibroblast activating protein (FAP) on the surface of CAFs was modified on HA to achieve precise targeting of CAFs, open the physical barrier of tumour cells and improve the deep penetration effect of the tumour, while introducing thioketone bond and ketone condensation bond to take advantage of the highly reactive ROS and low pH microenvironment at the tumour site to achieve chemical bond breaking of nano micelles encapsulating paclitaxel (PTX), drug release, and thus drug aggregation at the tumour site and improved bioavailability of the drug.
Keywords: ROS response; Tumour-associated fibroblasts; anti-fibrosis; deep penetration; dual targeting; nanoparticles.