Аннотация:Molecular dynamics (MD) approach employing an all-atom force field and special procedures was used to model and design nanocontainers for inclusion of biocompounds and delivery through lipid membrane. Carbon nanotubes may serve as non-immunogenic containers of biocompounds and vehicles delivery to the cell membrane. These two properties – inclusion and transportation – are interconnected and establish the main challenge in nanovehicle design. MD simulation of systems containing a carbon nanotube, water, a lipid bilayer, and a molecule to be delivered is a way to explore the problem.
Release of the peptide was performed by expulsing it in various media, including the lipid membrane. A set of swelling model spheres emulated the releasing compound (it is supposed that some external signal such as light is needed for the activation of release). For this purpose a modified variant of steered molecular dynamics (SMD) was developed. The conformational state of the peptide was studied in view of chemical stability of the substance under the shock action. The initial helical conformation deformed most greatly at ejection of the polypeptide into vacuum and least of all – into the membrane. Apparently, the environment plays a deforming and structure-forming role in this process. Conformational changes of the polypetidemolecule are reducedwith a decrease of the swelling rate.
