Dynamic formation of fibrin network: A novel aspect by computer simulations.

Abstract

The aim of our review article is to provide an understanding of how fibrin monomers are able to assemble into a visible network structure. It is based on well-known evidence of fundamental molecular studies, and on our results by a computer simulation as well as by calculation of logistic equation. The simulation was carried out by use of a physical process of percolation clustering programmed by Mathematica, and the calculation was carried out by Excel. Those mathematical models allowed us to present a novel dynamic mechanism of the fibrin coagulation. It consists of three fundamental steps. The first step occurs in liquid phase. Eight monomers assemble into protofibrils (0.05 nm in length, a module structure) followed by the second step; the association of those modules into a domain structure (0.6nm in length). The fibers in the domain keep growing with a concomitant two-way diversion, which is essential for the network formation. Then the final step takes place by the quick association of those domains until a visible network structure appears. Our computer simulation clearly demonstrated that there was a typical phase transition at the third step, which allowed a semi-solid crystallization of fibrins. Analysis by fast Fourier transform did show that there was no change in the components of the power spectra, while there was a change in the fractal dimensions before and after the phase transition. Confocal laser scanning microscopy demonstrated that there were many domains (nodes) and node-fiver-node structures. Thus the hypothetical steps described above would help to interpret the logistic growth of fibers as observed by photometric measurements. Therefore, our computer simulations, though it is a small-scale model, would provide the global understanding of the molecular assembly by self-organization.