An in situ microenvironmental nano-regulator to inhibit the proliferation and metastasis of 4T1 tumor

摘要

Tumor microenvironment, such as hypoxia and presence of immune cells, plays a critical role in cancer initiation, growth as well as progression, and seriously affects antitumor effect. Accordingly, we constructed a kind of multifunctional nanoparticles (NPs) with macrophage transformation and oxygen (Osub2/sub) generation characteristics, to regulate the tumor microenvironment. Methods: In this study, we synthesized mesoporous Prussian blue (MPB) NPs with low molecular weight hyaluronic acid (LMWHA) surface modification (LMWHA-MPB), and discovered that LMWHA-MPB could be used as an in situ macrophages converter and Osub2/sub generator. Results: In vitro results showed after uptake by M2 macrophages, LMWHA-MPB displayed the potential in remodeling tumor-associated macrophages (TAMs) phenotype (pro-tumor M2→anti-tumor M1), and anti-metastatic effect on 4T1 cells. Furthermore, in vivo visualized near-infrared (NIR) imaging data proved IR783 labeled LMWHA-MPB NPs could selectively accumulate in tumor sites. Then plenty of Osub2/sub generated to alleviate tumor hypoxia via catalytic decomposition of endogenous hydrogen peroxide (Hsub2/subOsub2/sub). Based on these outstanding characteristics, LMWHA-MPB NPs were adopted as multifunctional nanocarriers to load sonosensitizer hematoporphyrin monomethyl ether (HMME) for Osub2/sub self-provided sonodynamic therapy (SDT). In vivo anti-tumor results showed LMWHA-MPB/HMME could effectively inhibit the proliferation and metastasis of 4T1 tumors by improving tumor microenvironment. Conclusion: The multifunctional NPs can be used as in situ microenvironmental nano-regulators to inhibit the proliferation and metastasis of 4T1 tumor.