Cur-loaded ZnFe2O4@mZnO@N-GQDs biocompatible nano-carriers for smart and controlled targeted drug delivery with pH-triggered and ultrasound irradiation

In the present study a pH/ultrasound (US)-responsive nano-carriers based on magnetic core-shell ZnFe2O4@mZnO@GQDs and ZnFe2O4@mZnO@N-GQDs ternary composite was prepared. The smart nano-carrier contain a magnetic zinc ferrite (ZnFe2O4) core, mesoporous zinc oxide (mZnO) and graphene quantum dots doped with nitrogen (N-GQDs) interlayer shell that prepared by sol-gel and/or the hydrothermal methods. This nano-carrier was used for pH/ultrasound-controllable curcumin (Cur) reagent release. The structural, thermal and morphological properties of each nano-carrier was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), surface area measurements, transmission electron microscopy (TEM), selected area electron diffraction pattern (SAEDP) image, field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), thereto gravimetric analyzer (TGA), dynamic light scattering (DLS), zeta potential, and Brunauer -Emmett -Teller (BET). Also, the cytotoxicity assay of nano-carriers have been studied on the fibroblast and Hela cells. No in vitro cytotoxic effects have observed at high concentration (75 w/mL) of nanocarriers. The Cur drug loading efficiency of nano-carriers were as high as 76.45% w/w (ZnFe2O4@rnZnO-N-GQDs) and 64.71% w/w (ZnFe2O4@mZnO-GQDs). The loaded Cur can be sustainably released, and could be controlled by US irradiation and pH adjustment. Thus, these core-interlayer-shells are suitable for smart and controlled targeted drug release by using pH and US irradiation. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, a pH/ultrasound-responsive nano-carrier was prepared based on a magnetic core-shell structure and graphene quantum dots doped with nitrogen interlayer shell for controlled release of curcumin. The properties of the nano-carrier were extensively investigated and cytotoxicity assays were conducted on cells, showing no cytotoxic effects at high concentrations. The loaded curcumin exhibited high loading efficiency and sustained release, controllable by ultrasound irradiation and pH adjustment, making it suitable for targeted drug delivery.