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By Lay Leng TAN
ingapore employs nanotechnology in the development
of methods for diagnosis and subsequent possible
therapies.
Why do scientists employ nanotechnology in cellular study
when the living cells are typically in the micro range of 10–30
micrometres? Proteins and enzymes that drive the activities and
functions of living cells actually interact on the molecular level,
explains Kam W Leong, a professor of biomedical engineering at
Johns Hopkins School of Medicine. Ligands (small molecules) bind
to receptors on cell surfaces and convey signals through different
pathways to reach the cell nucleus, which interprets and acts on
messages.
Research has found that cells respond to the nanoscale features
on surfaces to which they attach, with some oddities noted. For
example, when they attach onto a nanofibre mesh, cells exhibit
some interesting behaviour.
One hypothesis states that when cells attach to the nanofibre
surface via ligand-receptor interaction, signals are transduced
(transferred) into the cell, resulting in the up-regulation (a process
that increases ligand-receptor interaction due to an increase in
the number of available receptors) or down-regulation of some
genes.
However, recent studies have shown that signal transduction
depends not only on the density of the ligand but also on its
clustering. This action in turn causes receptor clustering, which
gives rise to a more potent response. Biologists believe
this result has to do with proteins on the other side
of the cell surface that come together to trigger the
signal transduction.
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