Injectable supramolecular hybrid hydrogels formed by MWNT‐<i>grafted</i>‐poly(ethylene glycol) and α‐cyclodextrin

Abstract

Abstract Poly(ethylene glycol)‐ grafted ‐multiwalled carbon nanotube (MWNT‐ g‐ PEG) was synthesized by a coupling reaction and formed inclusion complexes (ICs) after selective threading of the PEG segment of the MWNT‐ g‐ PEG through the cavities of α‐cyclodextrins (α‐CDs) units. The polypseudorotaxane structures of the as‐obtained hydrogels were confirmed by 1 H NMR, X‐ray diffraction and DSC analyses. The complexation of the PEG segments with α‐CDs and the hydrophobic interaction between the MWNT resulted in the formation of supramolecular hybrid hydrogels with a strong network. Thermal analysis showed that the thermal stability of the hydrogel was substantially improved by up to 100 °C higher than that of native hydrogel. The resultant hybrid hydrogels were found to be thixotropic and reversible, and could be applied as a promising injectable drug delivery system. The mechanical strength of the hybrid hydrogels was greatly improved in comparison with that of the corresponding native hydrogels. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3145–3151, 2010