title: Smart nanocomposite hydrogels based on azo crosslinked graphene oxide for oral colon-specific drug delivery.
abstract: A safe and efficient nanocomposite hydrogel for colon cancer drug delivery was synthesized using pH-sensitive and biocompatible graphene oxide (GO) containing azoaromatic crosslinks as well as poly (vinyl alcohol) (PVA) (GO-N=N-GO/PVA composite hydrogels). Curcumin (CUR), an anti-cancer drug, was encapsulated successfully into the hydrogel through a freezing and thawing process. Fourier transform infrared spectroscopy, scanning electron microscopy and Raman spectroscopy were performed to confirm the formation and morphological properties of the nanocomposite hydrogel. The hydrogels exhibited good swelling properties in a pH-sensitive manner. Drug release studies under conditions mimicking stomach to colon transit have shown that the drug was protected from being released completely into the physiological environment of the stomach and small intestine. In vivo imaging analysis, pharmacokinetics and a distribution of the gastrointestinal tract experiment were systematically studied and evaluated as colon-specific drug delivery systems. All the results demonstrated that GO-N=N-GO/PVA composite hydrogels could protect CUR well while passing through the stomach and small intestine to the proximal colon, and enhance the colon-targeting ability and residence time in the colon site. Therefore, CUR loaded GO-N=N-GO/PVA composite hydrogels might potentially provide a theoretical basis for the treatment of colon cancer with high efficiency and low toxicity.
authors.affiliation: School of Pharmaceutical Sciences, Zhengzhou University, 100 Science Road, Zhengzhou 450001, People's Republic of China. Collaborative Innovation Center of New Drug Research and Safety Evaluation, Henan Province, Zhengzhou 450001, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Hou
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Shi
authors.forename: Guixiang
authors.initials: G
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Huili
authors.initials: H
authors.lastname: Han
authors.forename: Qianhua
authors.initials: Q
authors.lastname: Feng
authors.forename: Junxiao
authors.initials: J
authors.lastname: Ren
authors.forename: Yujie
authors.initials: Y
authors.lastname: Yuan
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinjin
authors.initials: J
authors.lastname: Shi
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Zhang