To overcome the limited
drug loading capacity of magnetic nanopharmaceuticals arising from the relatively large mass of the
metal core, a high-loading drug delivery system based on amino-functionalized Fe3O4 magnetic
nanospheres modified by hyperbranched
phenylboronic acid (HPBA-Fe3O4) were prepared for the first time. The obtained nanomaterials were characterized by transmission electron microscopy, Fourier transform infrared, zeta potential, elemental analysis, vibrating sample magnetometry and X-ray diffraction analysis, and the results showed that hyperbranched
phenylboronic acid (HPBA) were successfully grafted onto the surface of the magnetic
nanospheres. The polymerization conditions, adsorption and desorption performance, and
tumor-targeting ability of HPBA-Fe3O4 was investigated in detail through chemical and
biological experiments. The
drug loading amount and capacity of HPBA-Fe3O4 are 271.3 mg/g and 27.13%, respectively, which are 2.26 and 3.27 times greater than those of PBA-Fe3O4 and PEI-Fe3O4, and the thermodynamic fitting results further demonstrate the high
drug loading ability of HPBA-Fe3O4. In vitro studies performed in U-87 MG
malignant glioma cells and astrocytes via light and fluorescence microscopy analyses, cell counting kit-8 assays, and HPLC tests confirm the pH-sensitive release and
tumor-targeted
drug delivery capabilities of HPBA-Fe3O4. The facile fabrication of hyperbranched magnetic nanomaterials could be an alternative
solution for designing high-loading,
tumor cell-targeting and pH-responsive DDSs with high-mass cores.