theoretical study of drug delivery on sn (ch3)2(n-acetyl-l-cysteinate) with swcnt

the interaction of anticancer drug sn (ch3)2(n-acetyl-l-cysteinate) with carbon nanotube (cnt)is investigated by quantum chemical ab initio calculations at fif/ (lanl2dz+sto-3g) and hf/(lanl2dz+6-31g) levels in gas phase and solution. the solvent effect is taken into account viathe self-consistent reaction field (scrf) method. carbon nanotubes can act as a suitable drugdelivery vehicle for internalization, transportation and translocation of sn (ch3)2(nca) withinbiological systems. thermodynamical analysis indicate that the relative energies (ae), enthalpies(mi) and free gibbs energies (ag) are negative for sn (ch3)2(nca) —cnt system but thecalculated entropies (as) are positive, suggesting thermodynamic favorability for covalentattachment of sn (ch3)2(nca) into carbon nanotube. also, the results show that with increasingdielectric constant of solvent the stability of sn (ch3)2(nac) — cnt complex decreases.furthermore, anisotropic chemical shift tensor (acr), total atomic charge and asymmetry parameter(q) have been calculated using the ciao method, results being compared with cgst data. fromthe nmr calculations, it can be seen that the nmr (aa.q) parameters at the sites of nitrogen,oxygen as well as c-2 and c-3 nuclei are significantly influenced by intermolecular hydrogenbondinginteractions but the quantity at the site of s-27 is influenced by nonspecific solute-solventinteraction such as polarizability/polarity.