  Efficient and non-invasive techniques of cargo delivery to biological cells
are the focus of biomedical research because of their great potential
importance for targeted drug therapy. Therefore, much effort is being made to
study the characteristics of using nano-based biocompatible materials as
systems that can facilitate this task while ensuring appropriate self-sealing
of the cell membrane. Here, we study the effects of indentation and withdrawal
of nanospear on phospholipid membrane by applying steered molecular dynamics
(SMD) technique. Our results show that the withdrawal process directly depends
on the initial position of the nanocone. The average force and work are
considerably more significant in case of the withdrawal starting from a larger
depth. This result is attributed to stronger hydrophobic interactions between
the nanocone and lipid tails of the membrane molecules. Furthermore, when the
indenter was started from the lower initial depth, the number of lipids removed
from the membrane was several times smaller than the deeper indentation. The
choice of the least invasive method for nanostructure-assisted drug delivery is
crucial for possible applications in medicine. Therefore, the results presented
in this work might be helpful in efficient and safe drug delivery with
nanomaterials.
