Abstract:
Chemotherapy with anti-cancer drugs is considered the most common
approach for killing cancer cells in the human body. However, some barriers such as toxicity and
side effects would limit its usage. In this regard, nano-based drug delivery systems have emerged
as cost-effective and efficient for sustained and targeted drug delivery. Nanotubes such as carbon
nanotubes (CNT) and boron nitride nanotubes (BNNT) are promising nanocarriers that provide the
cargo with a large inner volume for encapsulation. However, understanding the insertion process of
the anti-cancer drugs into the nanotubes and demonstrating drug-nanotube interactions starts with
theoretical analysis. Methods: First, interactions parameters of the atoms of 5-FU were quantified
from the DREIDING force field. Second, the storage capacity of BNNT (8,8) was simulated to
count the number of drugs 5-FU encapsulated inside the cavity of the nanotubes. In terms of the
encapsulation process of the one drug 5-FU into nanotubes, it was clarified that the drug 5-FU was
more rapidly adsorbed into the cavity of the BNNT compared with the CNT due to the higher van
der Waals (vdW) interaction energy between the drug and the BNNT. Results: The obtained values of
free energy confirmed that the encapsulation process of the drug inside the CNT and BNNT occurred
spontaneously with the free energies of −14 and −25 kcal·mol−1
, respectively. Discussion: However,
the lower value of the free energy in the system containing the BNNT unraveled more stability
of the encapsulated drug inside the cavity of the BNNT comparing the system having CNT. The
encapsulation of Fluorouracil (5-FU) anti-cancer chemotherapy drug (commercial name: Adrucil®)
into CNT (8,8) and BNNT (8,8) with the length of 20 Å in an aqueous solution was discussed herein
applying molecular dynamics (MD) simulation