The
research team from Nottingham University showed how click-chemistry could be
used to attach fluorescent molecules or antibodies to spider silk that is
artificially produced by E.coli.
‘Infusing spider silk fibers with antibiotics like levofloxacin can improve wound healing, drug delivery and regenerate tissue.’
Click
chemistry was a term coined by K. B. Sharpless in 2001 to detail high yielding
reactions with a wide scope, and which results in byproducts that can be
separated without the need for chromatography. This methodology was
conceptualized to cater to the needs of the materials, pharmaceutical and other
industries to generate large libraries of compounds that are required in research for screening.
The
molecules that are chosen should be 'clicked' within soluble silk protein,
prior to turning them into fibers or even after the development of the fibers.
There is a lot of control that can be exerted in the development of these
fibers and they can be clicked with more than one type of molecule.
Recombinant Technology
The
antibiotic levofloxacin was added onto the silk fibers and was slowly released
from the fibers for at least 5 days. Dr. Neil Thomas who is a Professor of
Medicinal and Biological Chemistry said that the technique allowed fast
generation of biocompatible silk structures with mono or multiple functions
which could be used for a range of applications. The research team said that
this technology could be particularly useful in tissue engineering and
biomedicine.
Benefits of Spider
Silk
- Spider silk is
strong, biodegradable and biocompatible.
- This material is
based on protein and does not lead to a strong immune, inflammatory or
allergic reaction.
Spider silk has been known to possess remarkable
properties like showing high level of strength, flexibility, torsionality as
well as a lightness that is unmatched by any other man-made material. Another
significant factor about spider silk is its ability to survive for a long
period in the environment even after the spider dies.
The
ability of spider silk to last for a long time is evidence that it can resist
the decomposition by micro-organisms. Studies
by scientists Vollra et al showed that the compounds that were present in
spider silk had anti-microbial property.
The
recent advances in recombinant spider silk technology have resulted in a race
to find ways to harness these qualities.
The
Research team from Nottingham University has shown that
- The technique can
be used to develop a biodegradable
mesh.
- It can be used to
replace the extracellular matrix generated by our own cells.
- This will aid in
the acceleration of the new tissue.
- It is also useful
in the slow release of antibiotics.
- It could be used
for the treatment of wounds that are slow healing like diabetic ulcers.
- Infection of
wounds can be prevented for weeks or even months by controlling the
release of the antibiotics.
- Regeneration of
the wound tissue is accelerated by the temporary scaffold provided by silk
fibers. The silk fibers are biodegraded after that.
Historical
Significance of Spider Silk
Historically,
the medicinal properties of spider silk have been known for many centuries.
Greek
and Roman soldiers were bandaged with spider silk to prevent bleeding. Honey
and vinegar were used to clean deep wounds while balled up spider webs were
used to cover the wound.
The
scientists included a method in which the silk proteins were produced in a
bacterium and an amino acid that was not normally found in a protein was
included. The amino acid that contained the azide group was widely used in
click reactions.
Dr.
Goodacre, another key researcher in the study said that it was a fascinating
adventure in identifying the amino acid and also incorporating the fibers with
antibiotics.
The
use of spider silk
could revolutionize wound healing, as the risk of infection is high
during this phase. When wounds are covered with such recombinant technology,
where spider silk releases antibiotics for a period of time, the risk of
infection is minimized.
Spider silk is already believed to have
antimicrobial effect for a short period of time, infusing their fibers with
antibiotics increases the antimicrobial effect and duration.
References :- David Harvey, Philip Bardelang, Sara L. Goodacre, Alan Cockayne, Neil R. Thomas. Antibiotic Spider Silk: Site-Specific Functionalization of Recombinant Spider Silk Using "Click" Chemistry. Advanced Materials, (2016); 1604245 DOI: 10.1002/adma.201604245
- Azide-Alkyne Cycloaddition - (http://www.organic-
chemistry.org/namedreactions/click-chemistry.shtm)
Source: Medindia
