Self‐assembled graphene oxide–gelatin nanocomposite hydrogels: Characterization, formation mechanisms, and pH‐sensitive drug release behavior

Abstract

Novel physically crosslinked graphene oxide (GO)-gelatin nanocomposite hydrogels were obtained by selfassembly. The hydrogels with various ratios of GO to gelatin were prepared, and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy. The static and dynamic rheological properties of the hydrogels were investigated, along with the underlying hydrogel formation mechanisms. The storage modulus of the hydrogels (containing 98-98.5 wt % water) reached 114.5 kPa, owing to the relatively strong physical bonding (i.e., hydrogen bonding and electrostatic forces) between GO and gelatin. Drug release tests showed that the drug release from the hydrogel was pH-dependent, with 96% of the model drug released in a neutral environment, compared to 28% released in an acidic medium. These hydrogels could have potential in pH-sensitive drug delivery. V C 2014

One-Step Synthesis of Graphene Oxide–Polyamidoamine Dendrimer Nanocomposite Hydrogels by Self-Assembly

“…With an increasing PAMAM content, the G band gradually shifts from 1598 cm -1 in GO to 1587 cm -1 in G10D30H, attributable to the charge transfer from PAMAM to GO sheets. 11,14 These results indicate the electrostatic attractions between GO and PAMAM. .…”

“…14 The single GO nanosheets have a thickness of 1.0 nm and a typical length of one to several microns 14 (with a new AFM image shown in the inset of Fig. 3(A)).…”

“…S1). FT-IR spectra of graphite, 14 GO, 14 neat PAMAM and lyophilized GO-PAMAM nanocomposite hydrogels are presented in Fig. 4(A).…”

“…Graphite (curve a) only possesses a weak peak at 3400 cm -1 from O-H stretching of residual water. 14 . 43 This further confirms that the PAMAM dendrimer was successfully synthesized.…”

“…11 Hydrogels self-assembled by mixing GO and cationic polymers in water were later also reported by others. [13][14][15] GO-polyamine hydrogels, including tris(aminoethyl)-amine, spermine, and spermidine, were formed driven by electrostatic interaction (mechanical properties not shown). 13 GO/branched polyethylenimine (PEI) hydrogels were reported for organic dye removal and wastewater treatment (mechanical properties not shown).…”