Designing new bioinspired 3D-hydrogels for bone-tissue regeneration

Molecular self-assembly is a key direction in the current nanotechnology and material science fields. In this approach, the physical properties of the formed assemblies are directed by the inherent characteristics of the specific building blocks. Molecular co-assembly at varied stoichiometry substantially increases the structural and functional diversity of the formed assemblies, thus allowing tuning of their architecture as well as their physical properties.

In particular, short peptide and amino acid building blocks can form ordered assemblies such as nanotubes, nanospheres and 3D-hydrogels. These assemblies were shown to have unique mechanical, optical, piezoelectric and semiconductive properties. Yet, the control over the physical properties of the structures is still challenging. For example, controlling nanotube length in solution is difficult due to the inherent sequential self-assembly mechanism. Another example is controlling the physical properties of 3D-hydrogel scaffolds, including mechanical strength, degradation profile and injectability, which are important for tissue engineering applications.

Here, in line with polymer chemistry paradigms, we applied a supramolecular polymer co-assembly methodology to modulate the physical properties of peptide nanotubes and hydrogel scaffolds. Utilizing this approach, we achieved a narrow distribution of peptide nanotube length by adjusting the molecular ratio between the two building blocks, namely the diphenylalanine assembly unit and its end-capped analogue. In addition, applying a co-assembly approach on hydrogel forming peptides resulted in a synergistic modulation of the mechanical properties, forming extraordinarily rigid hydrogels. Furthermore, we designed an organic-inorganic scaffold for bone tissue regeneration.

This work provides a conceptual framework for the utilization of co-assembly strategies to push the limits of nanostructure physical properties obtained through self-assembly.

References

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