Fig 1.
Model formations and parameters for (a) center of mass and normal vector of drug, (b) top-view through CNT axis, and (c) side-view of CNT.
Table 1.
Minimum energy (kcal/mol) obtained from cubic spline interpolation for drugs encapsulated in CNT of radius a (Å) where
(Å) denoted tube radius at zero energy.
Fig 2.
Relation of tube radii at minimum energy and corresponding configurations of two FUs encapsulated in CNTs.
Fig 3.
Relation of tube radii at minimum energy and corresponding configurations of two PFs encapsulated in CNTs.
Fig 4.
Relation of tube radii at minimum energy and corresponding configurations of two MBs encapsulated in CNTs.
Fig 5.
Relation of tube radii at minimum energy and corresponding configurations of two DOXs encapsulated in CNTs.
Table 2.
Numerical values of parameters describing configurations of two drugs encapsulated in CNTs of radii a (Å), where (Å) denotes the shortest distance from the drug’s center of mass to the tube surface,
(∘) is the separation angle between two drugs, and
(Å) is the distance between the two centers of masses along the CNT’s axis. Both configurations at global and local minima are analyzed.
Fig 6.
FUs maintain 3.47 Å distance from CNT wall, arranging in trellis and triangular patterns.
Examples of equilibrium locations both side- and top-view of FUs (a), (b) three, (c), (d) four, (e), (f) five and (g), (h) six molecules in CNTs of radii 10 Å.
Fig 7.
Planar structure of PF results in 3.50 Å spacing from CNT wall, and arranging in two-layer clusters or spiral staircase patterns with varied orientations.
Examples of equilibrium locations both side- and top-view of PFs (a), (b) three, (c), (d) four, (e), (f) five and (g), (h) six molecules in CNTs of radii 10 Å.
Table 3.
Parameters values defined in Sect 1.2 of fluorouracil encapsulated in CNT of radius Å with minimum energy
(kcal/mol).
Table 4.
Parameters values defined in Sect 1.2 of proflavines encapsulated in CNT of radius Å with minimum energy
(kcal/mol).
Table 5.
Parameters values defined in Sect 1.2 of methylene blue encapsulated in CNT of radius Å with minimum energy
(kcal/mol).
Fig 8.
Due to its larger size, MB exhibits 3.9–4.0 Å spacing from CNT wall and larger tilt angles.
It forms linear, spaced arrangements, but shifts to a two-layer structure with six molecules due to spatial constraints. Examples of equilibrium locations both side- and top-view of MBs (a), (b) three, (c), (d) four, (e), (f) five and (g), (h) six molecules in CNTs of radii 10 Å.
Table 6.
Parameters values defined in Sect 1.2 of doxorubicin encapsulated in CNT of radius Å with minimum energy
(kcal/mol).
Fig 9.
Due to its large size, a 10 Å CNT accommodates only 1–4 molecules.
DOX maintains a 4.6–4.9 Å center-of-mass distance from CNT wall, with larger tilt angles. Examples of equilibrium locations both side- and top-view of DOXs (a), (b) three and (c), (d) four molecules in CNTs of radii 10 Å.