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Protein molecules have the ability to form a rich variety of natural and artificial structures and materials. We show that amyloid fibrils, ordered supramolecular nanostructures that are self-assembled from a wide range of polypeptide molecules, have rigidities varying over four orders of magnitude, and constitute a class of high-performance biomaterials.(More)
We report the detailed mechanical characterization of individual amyloid fibrils by atomic force microscopy and spectroscopy. These self-assembling materials, formed here from the protein insulin, were shown to have a strength of 0.6 +/- 0.4 GPa, comparable to that of steel (0.6-1.8 GPa), and a mechanical stiffness, as measured by Young's modulus, of 3.3(More)
The development of single-walled carbon nanotubes for various biomedical applications is an area of great promise. However, the contradictory data on the toxic effects of single-walled carbon nanotubes highlight the need for alternative ways to study their uptake and cytotoxic effects in cells. Single-walled carbon nanotubes have been shown to be acutely(More)
We present an analytical treatment of a set of coupled kinetic equations that governs the self-assembly of filamentous molecular structures. Application to the case of protein aggregation demonstrates that the kinetics of amyloid growth can often be dominated by secondary rather than by primary nucleation events. Our results further reveal a range of(More)
Multi-walled carbon nanotubes (MWNTs) have been proposed for use in many applications and concerns about their potential effect on human health have led to the interest in understanding the interactions between MWNTs and human cells. One important technique is the visualisation of the intracellular distribution of MWNTs. We exposed human macrophage cells to(More)
Despite great interest in the engineering applications of carbon-based nanoparticles, recent studies have raised concerns about their potential toxicity and safety. The release of C(60) into the environment has been suggested to be a potential risk with possible ecological implications. Here we evaluate energy-filtered transmission electron microscopy(More)
Aggregation of proteins and peptides is a widespread and much-studied problem, with serious implications in contexts ranging from biotechnology to human disease. An understanding of the proliferation of such aggregates under specific conditions requires a quantitative knowledge of the kinetics and thermodynamics of their formation; measurements that to date(More)
Self-assembly processes resulting in linear structures are often observed in molecular biology, and include the formation of functional filaments such as actin and tubulin, as well as generally dysfunctional ones such as amyloid aggregates. Although the basic kinetic equations describing these phenomena are well-established, it has proved to be challenging,(More)
Water-soluble single-walled nanotubes (SWNTs) are being tested as contrast agents for medical imaging and for the delivery of therapeutically active molecules to target cells. However, before they become used commercially, it will be essential to establish their subcellular distribution and whether they are cytotoxic. Here we characterize uptake of(More)
In nature, sophisticated functional materials are created through hierarchical self-assembly of simple nanoscale motifs. In the laboratory, much progress has been made in the controlled assembly of molecules into one-, two- and three-dimensional artificial nanostructures, but bridging from the nanoscale to the macroscale to create useful macroscopic(More)