Page 44 - Biennial Report 2018-20 Jun 2021

PEPTIDE DECORATED ZnO NANOPARTICLES FOR SELECTIVE KILLING OF
CANCER CELLS

Melanoma is an aggressive skin cancer of the pigment producing cells called melanocytes.
Supported by funding from the Department of Science and technology, Munia Ganguli, is
attempting to selectively kill cancer cells by using ZnO nanoparticles in combination with
peptides. Preparation of ZnO nanoassembly with different sizes of ZnO nanoparticles, surfaced
modified with skin penetrating (M9) and apoptotic (ATAP) peptide, will be followed by studies
on potentially selective impact of this novel nanoparticle assembly on melanoma and non-
melanoma skin cells. Such studies would enhance understanding of the mechanism of selective
killing of melanoma cells, using ZnO+M9+ATAP nanoassembly.

The project involves creating a nanoassembly of ZnO nanoparticles that are surface decorated
with a cell and skin penetrating peptide M9 and two different apoptotic peptides ATAP and
LbcinB6. The apoptotic peptides were linked to the nanoparticle using an MMP-1 cleavable linker
with the aim that on selective cleavage and release of the peptide in melanoma cells, the
apoptotic peptide will target mitochondria and disturb their membrane integrity, resulting in
apoptosis. Additionally, a more exposed nanoparticle surface will allow leaching of Zn2+ which
will induce ROS production and indirect cell killing as well. 30 nm sized ZnO nanoparticles were
conjugated with LbcinC6 and ATAP apoptotic peptide in separate nanoassemblies and these
were characterized using Transmission Electron Microscopy and Dynamic Light Scattering. The
nanoassemblies were added to melanoma and non-melanoma skin cells and cytotoxicity was
measured at different time points.

It was analyzed whether
the cytotoxic effects of
the peptide modified
ZnO nanoparticles was
associated with
apoptosis. Cell cycle
analysis was done in
case of the LbcinB6
modified nanoparticles.
B16-F10 cells were
treated with the bare
and modified
nanoassemblies and the
cell cycle analysis was
done using flow
cytometry. The
aberrations in the cell
cycle indicated that the
peptide modified
nanoassemblies
facilitate apoptosis. Further, intracellular ROS production was measured in B16-F10 cells after

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