Preparation of Graphene Oxide-Based Supramolecular Hybrid Nanohydrogel Through Host-Guest Interaction and Its Application in Drug Delivery.

Graphene oxide (GO) has attracted a wide attention for its excellent mechanical, thermal properties and unique two-dimensional structure. In this work, A new GO-based supramolecular hybrid nanohydrogel was prepared, in which GO as the cross-links was incorporated into the above hydrogel through non-covalent functionalization to enhance the mechanical properties and control morphology. A 1-pyrenebutyric acid (Py) modified low-molecular weight (MW) mPEG was firstly synthesized via a simple esterification reaction. Then, low-MW mPEG functionalized GO (GO-Py-PEG) was obtained due to the strong - stacking interaction between Py and GO. The combination of the host-guest interaction between mPEG and -CD and addition of GO lastly leaded to the formation of supramolecular hybrid nanohydrogel. Various techniques including UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM) were used to thoroughly characterize the hybrid hydrogel. More interestingly, the results of rheology studies and scanning electron microscopy (SEM) revealed that the mechanical strength and morphology of hybrid hydrogel was improved by the incorporation of GO. Meanwhile, doxorubicin hydrochloride (DOX) as a model drug was loaded into hybrid hydrogel, and the released behavior was studied under different pH values. The results showed that the formed hybrid hydrogel could release DOX over 50 h in a sustained manner. In addition, and experiments, GO-Py-PEG--CD@DOX hydrogel (hydrogel@DOX) dramatically shows the inhibition of tumor cell proliferation and tumor growth. At the same time, HE staining results show hydrogel@DOX can significantly reduce the side effects of DOX. We believe that the development of such hybrid hydrogels will provide important potential for medical applications.