posted on 2020-01-02, 22:43authored byYunchao Xiao, Lizhou Lin, Mingwu Shen, Xiangyang Shi
The
isolation of viable
circulating tumor cells (CTCs) from blood is of paramount significance
for early stage detection and individualized therapy of cancer. Currently,
CTCs isolated by conventional magnetic separation methods are tightly
coated with magnetic materials even after attempted coating removal
treatments, which is not conducive for subsequent analysis of CTCs.
Herein, we developed DNA aptamer-functionalized magnetic short nanofibers
(aptamer–MSNFs) for efficient capture and release of CTCs.
In our work, polyethylenimine (PEI)-stabilized Fe3O4 nanoparticles with a mean diameter of 22.6 nm were first
synthesized and encapsulated within PEI/poly(vinyl alcohol) nanofibers
via a blended electrospinning process. After a homogenization treatment
to acquire the MSNFs, surface conjugation of the DNA aptamer was performed
through thiol–maleimide coupling. The formed aptamer–MSNFs,
with a mean diameter of 350 nm and an average length of 9.6 μm,
display a saturated magnetization of 12.3 emu g–1, are capable of specifically capturing cancer cells with an efficiency
of 87%, and enable the nondestructive release of cancer cells with
a release efficiency of 91% after nuclease treatment. In particular,
the prepared aptamer–MSNFs displayed a significantly higher
release efficiency than commercial magnetic beads. The designed aptamer–MSNFs
may hold great promise for CTC capture and release as well as for
other cell sorting applications.