Tumor targeting antibody-conjugated nanocarrier with pH/thermo dual-responsive macromolecular film layer for enhanced cancer chemotherapy.

In response to changeful tumor environment, self-targeting antibody-mediated drug nanocarrier with functionalization have been broadly developed to realize specific antitumor efficacy. In this work, an antibody-conjugated drug delivery system with pH/temperature dual-responsive property was devised and fabricated based on mesoporous silica nanoparticle (MSN). Briefly, MSN was first modified with the pH/temperature dual-responsive macromolecular copolymer P(NIPAm-co-MAA) via a precipitation polymerization method, and then grafted with the anti-human epidermal growth factor receptor 2 (HER2) single chain antibody fragment (scFv) to specifically target HER2 positive breast cancer cells. With this structure, such targeting nanoparticles eventually exhibited high drug loading capacity and good biocompatibility. Meanwhile, the cumulative in vitro drug release profile displayed a low-level early leakage at neutral pH values/low temperature while remarkably enhanced release at an acidic pH value/high temperature, indicating an apparent pH/temperature-triggered drug release pattern. Moreover, tumor-targeting assay revealed that the anti-HER2 scFv-surface decoration greatly enhanced the cellular uptake of as-prepared nanoparticle through HER2-antibody-mediated endocytosis, as well as improved the uptake selectivity between normal and cancer cells. More importantly, both the in vitro and in vivo anticancer experiments indicated that such targeting dual-responsive nanoplatform could efficiently inhibit the growth of HER2 positive breast cancer with minimal side effects. Collectively, all these results promised such specific-targeted and dual-responsive nanoparticle a smart drug delivery system, and it provided a promising perspective in efficient and controllable cancer therapeutic application.