Lipid microtubules are fabricated by molecular self-assembly method from biologically-derived lipid,and the helical characteristics of lipid microtubules are primarily summarized on the basis of many investigations.It was indicated that lipid microtubules are the stable microstructures formed by tightly twisted ribbons, and there are a few loose helical ribbons.Meanwhile, there exist a few helical ribbons entrapped in the single wall lipid membrane, which means a new kind of lipid self-assembly morphology.The clearly helical pattern on tubules, the multi-bilayer microstructures caused by helical dislocation at the edge of ribbon, and the helical relaxation of ribbon at the top end of tubules, are the main characteristics of the lipid microtubules.They will have substantial effects on the following deposition of nanoparticles on microtubules and helical ribbons.The multi-layer depositions of Pd and Ni nanoparticles at the edge of ribbon clearly exhibit the dislocation of lipid bilayers, as well as the multi-layer microstructures of lipid membrane.Furthermore, the multi-layer deposition features of fine Pd nanoparticles at the edge of helical ribbon may be developed to label the number of lipid bilayers in self-assembled membrane.Meanwhile, the further research on the self-assembly of helical ribbon will be beneficial to revealing the nature of lipid self-assembly, and it will play an important role in research on biomineralization and mechanic property of biological membrane.

Key words: molecular self-assembly, lipid microtubule, helical ribbon