Nanomanipulation and aggregation limitations of self-assembling structural proteins

Abstract Collagen, the most abundant protein on Earth, is used as a platform for studying three major hurdles of nanotechnology: (1) What is the aggregation limit in self-assembling systems? (2) What is the smallest scale at which matter can be reliably and repeatedly organized? (3) Where do the natural boundaries lie in what is achievable via directed manipulation at the nanoscale? Through work involving a mechanics-based model for predicting the radial aggregation limit of collagen fibrils using translation length, axial and torsional stiffness of the tropocollagen model, and specific binding sites, the 20–500 nm diameter distribution of collagen is explored, verifying previous atomic force microscopy data. Preliminary micromanipulation of collagen fibers with the Zyvex S100 also implicate the necessary steps to be taken in proposed nanomanipulation experiments. Results presented implicate: (1) That the aggregation limit of collagen fibrils and perhaps other structural proteins may be predicted by the mechanical properties of its molecular subunits wherein the outer portions of the fibril are in tension balanced by compressive stresses within the inner portions, (2) That currently the top-down style of nanomanipulation must be improved via advances in computational imaging if it is to keep pace with advancements which have been made at the microscale, and (3) That there exist tightly constrained paths which must be followed in order to create beneficial mutations at the molecular level.