Supramolecular Hydrogels Assembled from Nonionic Poly(ethylene glycol)-b-Polypeptide Diblock Containing OEGylated Poly-L-glutamate Supramolecular Hydrogels Assembled from Nonionic Poly(ethylene glycol)-b-Polypeptide Diblock Containing OEGylated Poly-L-glutamate

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Supramolecular Hydrogels Assembled from Nonionic Poly(ethylene glycol)-b-Polypeptide Diblock Containing OEGylated Poly-L-glutamate

Polym.Chem.,2014.

Shusheng Zhang, Wenxin Fu* and Zhibo Li*

Poly(ethylene glycol)-b-poly(γ-(2-methoxyethoxy)esteryl-L-glutamate) (PEG-b-poly-L-EG2Glu) diblock was prepared by ring-opening polymerization (ROP) of L-EG2Glu N-carboxyanhydride (NCA) using PEG-NH2 as the macroinitiator. When the average degree of polymerization (DP) for poly-L-EG2Glu was below 40, the PEG-b-poly-L-EG2Glu diblock could spontaneously form hydrogels in water. For different diblocks, thermal-induced increase of mechanical strength was observed for PEG-b-poly-L-EG2Glu diblock within 20~45 °C. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed that continuous network of nanoribbons were formed in these hydrogel samples. Circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) characterizations suggested that formation of sufficient β-sheet content accounted for the nanoribbon assemblies and hydrogel networks. The minimal gelation concentration and gel mechanical properties were found to strongly depend on the composition of PEG-b-poly-L-EG2Glu diblocks.