(226i) Computer Simulation of Single Dendrimer Nanocarrier Loaded with Drug Molecules

Computer simulation of guest-host complex and conjugate on the base of single dendrimer molecule was performed by molecular dynamics methods. Carboxy terminated PAMAM dendrimer of generation 4.5 was used as host molecule. Complex/conjugate contains also 7-8 guest drug molecules per dendrimer. Simulation was performed in water box with periodical boundary conditions at constant pressure and temperature. We found that the structure of dendrimer is affected by guest molecules. In particular dendrimer-drug complex has more open and anisotropic structure and shape than PAMAM dendrimer itself. The distribution of guest molecules relatively dendrimer centre was calculated also. It was shown that drug molecules (both attached to terminal groups and physically adsorbed on surface) could change their positions and penetrate into dendrimer interior. Chemically attached drug molecules penetrate deeper than adsorbed ones. The characteristic times for penetrations/release of drug molecules were evaluated. Pair correlation functions between drug and dendrimer atoms and drug-drug atoms were calculated. It was shown that there is correlation between positions of drug molecules and some dendrimer atoms. At the same time no correlation between positions of different drug molecules was found.