Natively Unfolded State for Engineering Nanoscale Fibrillar Arrays

Linear and orthogonal peptide templating of silicified protein fibres

Biomineralisation is essential for biology. Specialist proteins use peptide motifs that catalyse mineral deposition into nano-to-microscale inorganic materials. Unlike in native proteins, the motifs incorporated into self-assembled fibres can persistently propagate on the microscopic scale enabling empirically defined silica nanostructures. Herein we show that the two main modes of motif templating - linear and orthogonal - in self-assembling, fibre-forming peptide sequences effectively silicify protein fibres. We show that the mere charge and morphology of protein fibres are not sufficient for silica deposition, but it is the synergy between fibrillogenesis and silica-specific motifs regularly spaced in fibres that ensures silica templating, regardless of the relative orientation of the motifs.

Impact of multivalent charge presentation on peptide-nanoparticle aggregation

Strategies to achieve controlled nanoparticle aggregation have gained much interest, due to the versatility of such systems and their applications in materials science and medicine. In this article we demonstrate that coiled-coil peptide-induced aggregation based on electrostatic interactions is highly sensitive to the length of the peptide as well as the number of presented charges. The quaternary structure of the peptide was found to play an important role in aggregation kinetics. Furthermore, we show that the presence of peptide fibers leads to well-defined nanoparticle assembly on the surface of these macrostructures.

Peptide-directed self-assembly of functionalized polymeric nanoparticles part I: design and self-assembly of peptide-copolymer conjugates into nanoparticle fibers and 3D scaffolds

A robust self-assembly of nanoparticles into fibers and 3D scaffolds is designed and fabricated by functionalizing a RAFT-polymerized amphiphilic triblock copolymer with designer ionic complementary peptides so that the assembled core-shell polymeric nanoparticles are directed by peptide assembly into continuous "nanoparticle fibers," ultimately leading to 3D fiber scaffolds. The assembled nanostructure is confirmed by FESEM and optical microscopy. The assembly is not hindered when a protein (insulin) is incorporated within the nanoparticles as an active ingredient. MTS cytotoxicity tests on SW-620 cell lines show that the peptides, copolymers, and peptide-copolymer conjugates are biocompatible. The methodology of self-assembled nanoparticle fibers and 3D scaffolds is intended to combine the advantages of a flexible hydrogel scaffold with the versatility of controlled release nanoparticles to offer unprecedented ability to incorporate desired drug(s) within a self-assembled scaffold system with individual control over the release of each drug.