Abstract:

Objective: To prepare magnetic Fe3O4 nanoparticles loading peptides derived from enzymatic hydrolysis of
hairtail processing waste proteins and explore its effect on membrane fluidity in CW-2 cells. Methods: The target product
was synthesized by co-precipitation method, and its structure characteristics and particle size distribution were observed with
X-ray diffraction (XRD), transmission electron microscope (TEM) and atomic force microscope (AFM). Meanwhile, its effect
on membrane fluidity in human colon cancer CW-2 cells was explored by fluorescence polarization in a non-magnetic field
and an alternating magnetic field. Results: Magnetic Fe3O4 nanoparticles loading hairtail peptides were uniformly distributed
with a size of approximately 10 nm and they were found to adhere to each other to form intertwined curves. Compared
with the single magnetic Fe3O4 particles, loading of hairtail peptides enhanced dispersion stability of magnetic nano-Fe3O4
particles. The optimum pH for magnetic Fe3O4 nanoparticles loading hairtail peptides was 6.5–9.0. Cell membrane fluidity
tests showed that P and η values in the experimental group were significantly reduced after 24 h of alternating magnetic field
exposure, indicating that the magnetic Fe3O4 nanoparticles loading hairtail peptides could increase cell membrane fluidity.
Conclusion: Magnetic Fe3O4 nanoparticles loading hairtail peptides can enhance the anti-tumor activity of hairtail peptides in
an alternating magnetic field.

Key words: magnetic Fe3O4 nanoparticles, hairtail enzymatic peptides, structure characterization, CW-2 cell, cell membrane fluidity