Preparation of pH responsive magnetic mesoporous nanoparticle drug loading system

We developed an intelligent drug delivery platform based on the mixture of magnetic mesoporous silica and polydopamine (PDA), which can be used for pH responsive drug delivery. Magnetic cores Fe3O4 was prepared by co-precipitation method. The magnetic nanomaterial Fe3O4@mSiO2 was obtained by the Stober method using cetyltrimethylammonium bromide (CTAB) as a template and tetraethyl silicate (TEOS) as a silicon source. Anticancer drug doxorubicin (DOX) was used as the model drug to be encapsulated into Fe3O4@mSiO2. The surface of the carrier was modified with pH-sensitive PDA coating by oxidation self-polymerization of dopamine at alkaline pH to obtain the magnetic nano drug loading system DOX/Fe3O4@mSiO2@PDA. The materials were characterized by Transmission electron microscope, X-ray diffraction, Fourier Transform infrared spectrometer, Brunauer Emmett Teller and vibration sample magnetometer. We found that Fe3O4@mSiO2 was spherical with good mesoporous structure and a specific surface area of up to 619.16m2/g. VSM indicated that the carrier Fe3O4@mSiO2@PDA had good magnetic properties. During the drug loading process, when DOX concentration was 0.5mg/mL, temperature was 37℃, and reaction time was 36h, the drug loading rate and encapsulation rate were up to 51.69% and 82.70%, respectively. The drug release curve showed that the nano drug delivery system had the characteristics of pH responsiveness and slow drug release. Thiazole blue colorimetric assay (MTT) cytotoxicity showed that Fe3O4@mSiO2@PDA had good biocompatibility, and DOX/Fe3O4@mSiO2@PDA had obvious inhibitory effect on cancer cells. The nano drug delivery system has a potential application prospect in targeted drug delivery. © 2023 Chemical Industry Press. All rights reserved.