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Cold
Plasma Treatment For Biomedical Applications
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Mrs.
Purvi Dave,
Scientist SC
Facilitation Center for Industrial Plasma
Technologies
Institute for Plasma Research,
Gandhinagar, Gujarat
fcipt@ipr.res.in
www.plasmaindia.com |
We all
have been taught that there are three states of
matter: solid, liquid and gas. The plasma is the
fourth state of matter. In a more simple way, we can
say plasma is an ionized gas. Scientists say that 99%
of universe is in plasma state. If we supply
sufficient energy to gas either in the form of heat or
electricity, electron comes out from the atom or
molecule and thus electrons, ions and reactive gaseous
chemical species are generated. In plasma stateions,
electrons, neutrals, activated gaseous species
coexist. We see natural plasmas around us in the form
of lightening and aurora. Sun and stars are live
example of natural plasma. Examples of common man made
plasmas are fluorescent lights, neon bulbs and plasma
arc, plasma TV etc.. Plasma arc is used for cutting
and welding of thick steel sheets.
Scientists and researchers around the world are
working to develop different plasma technologies for
variety of applications to serve mankind. Plasma state
can be generated in the laboratory. Plasma can be
generally classified broadly as: (i) non-thermal or
cold plasma and (ii) thermal or hot plasma.
Cold
Plasma (a kind of glow discharge) Treatment is very
much useful for surface modification of bio-polymers /
medical plastics. Bio-polymers / medical plastics are
widely used for biomedical applications such as
artificial organs (Prosthetic Materials) and cell
scaffolds. Surface properties of the material play an
important role in determining overall biocompatibility
of the materials because the surface of the materials
will first come into contact with biological
environment. The initial response of the biological
environment to such materials, therefore strongly
depend on the surface properties of the materials.
Thus the modification of the surface of the materials
is the convenient and effective way to create and
develop biomaterials for clinical applications. |
Although many synthetic
biomaterials have physical properties that meet and even
exceed those of natural body tissue, they can often cause
adverse physiological reactions such as infection,
inflammation and thrombosis formation. Through surface
modification, bio-compatibility as well as
bio-functionality can be achieved without changing bulk
properties of the material.
In order to obtain optimal
biological performance, it is usually necessary to apply
surface treatments or coatings to biomaterials. Plasma
treatments are used to incorporate chemically reactive
functional groups on to the polymer surface and thus make
them hydrophilic.
Hydrophilicity plays an
important role in cell and bacteria behaviour.It is
reported that enhancing the surface hydrophilicity by
introducing oxygen containing functional groups such as
hydroxyl (-OH), carbonyl (-COOH), ketone (-C=O) leads to
an increase in cell attachment. It is also reported that
Hydroxyl groups contributes to cell colonization.
It is well known that cell
walls of most bacterial strains are negatively charged.
Therefore more negative surfaces construct an initial
defence line against microbial adhesion by an
electrostatic repulsion. Air plasma treatment can
introduce negatively charged functional groups on the
surface. With increasing concentration of these groups,
the surface becomes more hydrophilic and more negatively
charged. Thereupon due to the strong repulsive forces, the
antibacterial effect increases [Fatemeh et al. Applied
Surface, Science 2015].
Similar type of research
work in the field of surface modification of polymer
surfaces by eco-friendly plasma process is being done at
Facilitation Centre for Industrial Plasma Technologies (FCIPT),
Institute for Plasma Research (IPR). IPR, Gandhinagar is
an Autonomous R & D Institute under the Department of
Atomic Energy (DAE), Government of India situated near
Gandhinagar, Gujarat, India.
FCIPT is a division under IPR,
which mainly focuses on technology development for social
benefits and industries. FCIPT develops plasma based
technologies and commercializes through Technology
Transfer to Industrial Partners.
In our study, plasma is
capable of reducing Water Contact Angle (WCA) from 100 ° (WCA
of untreated PE) to as low as 15 ° in the case of low
pressure plasma treatment and 43 ° in the case of
atmospheric pressure plasma treatment. WCA is the measure
of wettability of the material. Polyethylene is one of the
promising medical plastic which is widely used in various
prosthetics in biomedical industries.
At FCIPT, IPR we have
developed plasma surface modification process for polymers
which uses ambient air to produce plasma at atmospheric
pressure. After plasma treatment polymer surface
(Polyethylene, PET, PP) have become hydrophilic in nature,
which is of relevance to biocompatibility. This treatment
can also be done by low pressure air / oxygen plasma.
Below figure shows oxygen plasma generated in our
laboratory.
 In
our study, plasma is capable of reducing Water Contact
Angle (WCA) from 100°(WCA of untreated PE) to as low as
15° in the case of low pressure plasma treatment and 43 °
in the case of atmospheric pressure plasma treatment. WCA
is the measure of wettability of the material.
Polyethylene is one of the promising medical plastic which
is widely used in various prosthetics in biomedical
industries.
Results of water contact angle
and surface energy after atmospheric pressure air plasma
is shown in figure-2.
Incorporation of oxygen containing functional groups
after plasma treatment is shown in below figure-3. This
results are FTIR spectrographs.
Another device capable to
form plasma plume is Non Thermal Plasma Torch (NTP).
Recently FCIPT, IPR has developed a compact device NTP. A
plume of plasma comes out of this device. This type of
plasmas is useful for healing skin wounds, blood clotting
in few seconds. The plasma torch is like a small pen which
provides very narrow cold plasma plume which interacts
with skin or blood. Figure below shows view of a finger
exposed to this plasma. Dentists can use this torch for
cleaning cavity in effective manner or for root canal
treatment. The NTP has a potential to use in cancer
therapies as well. Conceptually this device can be
inserted in to lungs with a probe and lung nodules /
metastasis can be exposed for effective treatment. However
this application is yet under evaluation.
 FCIPT,
IPR welcomes interested organizations / industries to
contact us at below contact details.
Dr. Nirav Jamnapara
Technology Commercialization Cell
FCIPT, IPR
fcipt@ipr.res.in
www.plasmaindia.com
P:07923269017
FCIPT, IPR has organized one
day workshop on “Applications of Cold Plasma in Surface
Engineering” on September 11, 2015. Registration is Free.
Interested candidates can email us at
fcipt@ipr.res.in to
register. Pre-registration is compulsory. For more details
of this workshop please visit
www.plasmaindia.com
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