54(4), 2007, pp.861-868

Dissipative Particle Dynamics Simulations to Investigate Aggregation of Peptide Amphiphile Nanofibers

Rou-Yu Chen, Ling-Ying Wu, Jun-Min Liao and Cheng-Lung Chen*

Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C.

Abstract.     Dissipative Particle Dynamics (DPD) method was carried out to investigate the self-assembly phase behavior of peptide amphiphile (PA) molecules. The simulations showed that these molecules were self-assembled into three-dimensional fiber-like cylindrical aggregates by the assistance of water solvent. The results of DPD simulation are sensitive to various factors including the size of solvent bead, temperature, and the bead ratio of PA to solvent. We found that using 5 to 9 water cluster and solvent bead gives a result of the aggregation of PA molecules into cylindrical fibers. The criteria of forming nanofibers are bead ratios of PA to water larger than 1:6 and temperature above 340 K. The estimated diameter of the cylindrical aggregate agrees well with the experimentally measured value.

Keyword:  Computer simulation; Dissipative particle dynamics; Molecular dynamics; Peptide amphiphile; Nanofiber.