Theoretical evaluation of the nanocarrier properties of two families of functionalized dendrimers

Two families of dendrimers, denamide (oxy-amide) and denurea (oxy-urea), of second and third generation were designed as possible nanocarriers for high-spectral parasiticide drugs of the family of macrocyclic lactones. Their geometric description was carried out by Connolly's algorithm, obtaining molecular volumes and sizes of cavities. According to these calculations, about 50% of the total dendrimeric molecular volume in both families corresponds to cavities that are able to shelter guest drugs, forming complexes in ratios higher than 1:1. The molecular shape suffers more notorious changes, going through higher dendrimeric generations; therefore, third-generation dendrimers with two carbon atoms in their fractal patterns are more spherical than second-generation dendrimers with six carbon atoms in their fractal patterns. The experimentally studied host-guest system formed by PAMAM and ibuprofen (analgesic drug) was taken as a reference in the present study. Molecular dynamics and mechanics calculations were able to reproduce some experimental observations. Nevertheless, the interaction energies of some of the 1:1 complexes were calculated at the density functional theory (DFT) level. Comparing the fractal patterns of the denamide and denurea families with polyamidoamine dendrimers (PAMAM), the observed order of efficiency, in terms of favorable interactions with guest molecules, is as follows: denamide > PAMAM > denurea. The differences in functionalization are responsible for such behavior. (c) 2005 Wiley Periodicals, Inc.