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Transparent
Devices: In many applications the plastic parts have
to be transparent. Blister packs are one such example. Medicines whose
packaging must show very good barrier properties can be made from a crystal
clear film of cyclo-olefin copolymer. It supersedes the conventional polymers
used in such applications. During in-patient and out-patient care, tube lines
containing number of multi-way cocks or stop cocks and metering mechanisms are
used for supply of most diverse liquids. For this a plastic is necessary which
is transparent, and has very good chemical, fat and lipid stability. Amorphous
PET has been developed to fulfil these requirements.
Now-a-days
glass has been replaced by plastics in most of the labwares used in medical
research. The advantages of using plastics in Labwares such as Tissue culture
plates, Tissue culture flask, Cryogenic vials, tissue culture tubes,
centrifuge tubes, elisa plates, micropipette tips and petridishes is based on
their high precision, low weight, low cost and little care in handling.
Modifications in commodity plastics such as polypropylene, polystyrene and
polycarbonate have made it possible to fabricate labwares of desired
transparency and surface properties.
Degradable
Polymers: Polymers like poly (lactides), poly
(glycolides) and their copolymers have excellent properties and have thus been
developed for the applications such as wound closure, osteosynthesis, nets for
support while wound is healing, degradable bandages and surgical cord for
reinforcement, hollow fibres for treatment of damaged nerves as well as
prostheses for anastomoses.
For
example a biodegradable intravascular stent prototype is molded from a blend
of polylactide and trimethylene carbonate. Furthermore these polymers are
being considered for the development of products for the treatment of
paradontal diseases, fillers for tooth extraction, artificial vessels and drug
carrier systems. Why would a medical practitioner want a material to degrade?
There may be a variety of reasons, but the most basic begins with the
physician’s simple desire to have a device that can be used as an implant
and will not require a second surgical intervention for removal. Besides
eliminating the need for a second surgery, the bidegradation may offer other
advantages. For example, a fractured bone that has been fixated with a rigid,
non biodegradable stainless implant has a tendency for refracture upon removal
of the implant while, an implant prepared from biodegradable polymer can be
engineered to degrade at a rate that will slowly transfer load to the healing
bone.
Advances
in polymers for biotechnology are numerous. Now polymers have gone to the
extent that the difference between synthetic and biological polymers has
reduced to a great extent. Genetic engineering methods are being used to
produce "artificial" proteins with a range of designed structures
and functions. Traditional polymer synthesis techniques are being coupled with
biochemistry to produce materials that interact and control biological systems
and cells. Various new fields have emerged that club the role of polymer
chemistry with biotechnology.
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Environmentally responsive polymers for biotechnological
applications.
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Biological production of polymers (e.g., polystyrene, polyesters).
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Biopolymers and protein polymers.
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Polymers modified with biological -signals (e.g. adhesion peptides
growth factors).
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Bioactive, biomimetic, and bioinspired polymers.
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Supramolecular assemblies in biotechnology.
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Polymers in analytical biotechnology.
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Polymers scaffolds for tissue engineering.
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Biopolymer surfactants.
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Polymer and surface modification of tissue culture.
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Cell polymer interactions.
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Polymers for drug delivery and artificial organs.
In
the near future new generation materials promise to change the way medical
device manufacturers do business. While some device manufacturers will need to
replace conventional materials used in their products or seek materials
compatible with new drug therapies and treatment for illness, others may find
their products rendered obsolete by emerging techologies. It is not far away
when manufacturers of orthopedic implants may find waning customer demand for
their products as patients opt for synthetic bone-graft materials. Tissue
adhesives administered in a minimally invasive procedure may replace stapling
and suturing. In this situation, medical device manufacturers must not only
stay current, but also keep an eye on tomorrow to remain competitive.
Shri
VP Malhotra, RK Raina, Sanjay Rajput,Shriram Institute for Industrial
Research, 19 University Road, New Delhi-110007.
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