High drug loading system of hollow carbon dots doxorubicin: preparation, in vitro release and pH targeted research.
Hollow carbon dots (HCDs) as drug carriers, and doxorubicin (DOX) as a model drug, were selected to prepare a HCDs DOX loading system. First, HCDs were prepared by a hydrothermal method and characterized by transmission electron microscopy (TEM) powder X ray diffraction (PXRD) and nuclear magnetic resonance (13C NMR) UV vis absorption, Fourier transform infrared (FT IR) and X ray photoelectron spectroscopies (XPS) The HCDs were then used to load DOX. The drug loading system of HCDs DOX was characterized by zeta potential measurements, and UV vis absorption and fluorescence spectroscopies. We then studied the drug loading, formation mechanism, cytotoxicity, in vitro release and pH targeted properties. HCDs DOX was found to have a high drug (DOX) loading ratio ~42.9% and better sustained pH targeted release and lower cytotoxicity than those of DOX. In the HCDs DOX system, interactions between the HCDs and DOX were electrostatic resulting in the formation of N[double bond, length as m dash]C via the coupling of NH2 (on HCDs) and C[double bond, length as m dash]O (on DOX) In vitro release of HCDs DOX conformed to the Weibull model and Fick diffusion, consistent with that of free DOX. We report, for the first time, that the: (i) functional groups on the HCD surfaces (not their hollow structure) play a key role in drug loading; (ii) the carrier (HCDs) did not change the in vitro release model or mechanism of DOX before and after loading by the HCDs.
Journal of materials chemistry. B