Hydrogels formed by the self-assembly of peptides are promising biomaterials. The bioactive and biocompatible molecule Fmoc-FRGDF has been shown to be an efficient hydrogelator via a p-b self-assembly mechanism. Herein, we show that the mechanical properties and morphology of Fmoc-FRGDF hydrogels can be effectively and easily manipulated by tuning both the final ionic strength and the rate of pH change. The increase of ionic strength, and consequent increase in rate of gelation and stiffness, does not interfere with the underlying pb assembly of this Fmoc-protected peptide. However, by tuning the changing rate of the system's pH through the use of glucono-dlactone to form a hydrogel, as opposed to the previously reported HCl methodology, the morphology (nano-and microscale) of the scaffold can be manipulated.

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The properties and structures of viruses are directly related to the three-dimensional structure of their capsid proteins,w hich arises from ac ombination of hydrophobic and supramolecular interactions,such as hydrogen bonds.The design of synthetic materials demonstrating similar synergistic interactions still remains ac hallenge.H erein, we report the synthesis of ap olymer/cyclic peptide conjugate that combines the capability to form supramolecular nanotubes via hydrogen bonds with the properties of an amphiphilic blockcopolymer. The analysis of aqueous solutions by scattering and imaging techniques revealed ab arrel-shaped alignment of single peptide nanotubes into al arge tubisome (length:2 60 nm (from SANS)) with ahydrophobic core (diameter:16nm) and ahydrophilic shell. These systems,which have astructure that is similar to those of viruses,w ere tested in vitro to elucidate their activity on cells.Remarkably,the rigid tubisomes are able to perforate the lysosomal membrane in cells and release asmall molecule into the cytosol.

Enabling control over macromolecular ordering and the spatial distribution of structures formed via the mechanisms of molecular self-assembly is a challenge that could yield a range of new functional materials. In particular, using the self-assembly of minimalist peptides, to drive the incorporation of large complex molecules will allow a functionalization strategy for the next generation of biomaterial engineering. Here, for the first time, we show that co-assembly with increasing concentrations of a highly charged polysaccharide, fucoidan, the microscale ordering of Fmoc-FRGDF peptide fibrils and subsequent mechanical properties of the resultant hydrogel can be easily and effectively manipulated without disruption to the nanofibrillar structure of the assembly.