The multifunctional nano-carrier system can simultaneously achieve multiple functions such as diagnostic imaging, targeted delivery of anti-tumor drugs, and combined therapy. Application potential Fe3O4 magnetic nanoparticles have the characteristics of low toxicity,
superparamagnetism and good photothermal properties. Therefore, a multifunctional magnetic nanocarrier with both magnetic targeting and photothermal properties can be prepared by surface modification of Fe3O4 o DOX is an anti-tumor drug widely used in clinical treatment,
and its severe toxic and side effects greatly limit its application. In this paper, a temperature-sensitive magnetic nanocarrier was first constructed and proved to have good superparamagnetism, photothermal properties, and biocom-patibility Then, Fe3O4-Azo-DOX drug-loaded
nanoparticles were constructed by covalently bonding DOX. The prepared Fe3O4-Azo-DOX nanoparticles have high stability, sensitive photothermal response and low toxicity. Finally, Fe3O4-Azo-DOX was applied to the study of combined photother-motherapy
and chemotherapy in vitro and in vivo. Based on Fe3O4 nanoparticles, a temperature-sensitive Fe3O4-Azo nanocarrier was constructed and its related properties were characterized. Furthermore, anthracycline nanodrugs were used in chemotherapy
of breast cancer patients, and their effects were analyzed according to echocardiography parameter change. The results show that Fe3O4-Azo nanoparticles have a good photothermal heating effect. MCF-7 breast cancer cells were selected as a model to investigate the cytotoxicity
of Fe3O4-Azo. The results proved that they have excellent biocompatibility and can be used as drug carriers. A Fe3O4-Azo nanocarrier was used to load DOX to construct a NIR-responsive nano-drug delivery system. By studying the NIR controlled release
of Fe3O4-Azo-DOX under different pH conditions, it can be seen that it has NIR-responsive release function and the best release effect at pH 5.7. It was found that LVEF, LVFS, and E/A were significantly lower after chemotherapy than before (P < 0.05), which
had a certain clinical value in cardiotoxicity The in vitro antitumor effect of Fe3O4-Azo-DOX was studied, and the results showed that the combined effect of photothermal-chemotherapy was significantly better than the photothermal treatment based on Fe3O4-Azo
carrier alone and the chemotherapy based on free DOX alone.
The effect of surface coverage and conformation of poly(ethylene oxide) (PEO) chains of poloxamer 407 on the biological fate of model colloidal drug carriers