Polymers of microbe origin,
or biopolymers, have recently drawn increasing
attention of specialists. Biopolymers that are
auto destructible after some time have been
developed by Russian researchers. Obtained with
the help of bacteria, they are ideally suited
for healthcare. These polymers have two important
advantages. Firstly, they get destroyed in the
environment and thus solve the problem of contamination.
Secondly, being biocompatible they are not rejected
by an organism when applied for medical purposes.
These are polymers of ox derivative fatty acids,
the so-called polyhydroxyalkanoates (PHAs).
Some microorganisms, for example, hydrogen bacteria
that get vital energy via oxidizing hydrogen,
are able to synthesize PHAs. PHAs have a lot
of advantages - their physicochemical characteristics,
thermoplasticity, is the same as that of polypropylene
and polyethylene, and they possess antioxidant
and optical properties and piezoelectric effect.
Besides, like any biopolymers, they are compatible
with tissues of organism and get destroyed in
the environment. That is why their application
is promising for use in medicine (surgical and
disposable materials), pharmacology (prolongation
of drug action), food industry (packing and
antioxidant materials), agriculture (destructible
films).
Researchers first tested the polymer production
technology in the laboratory and then in production
environment. So far, the scientists can obtain
three types of polymers: polyoxybutyrate and
its copolymers with oxybutyrate and oxyvalerianate,
but in the future the range of goods will increase.
Within a week, 1 kilogram of polymer (or upto
50 kilograms pa) can be produced on the installation.
It is interesting to note that various articles
need absolutely different rate of polymer biodegradation
- suture threads and films should dissolve quickly,
but stents and valve prostheses should serve
for a long time. This is achieved by changing
the degradation rate that depends on the surface
type. Degradation rate can vary if different
fillings are used, or it can be accelerated
when needed through preliminary gamma irradiation.
The researchers are mainly interested in PHA
utilization for medical articles. Wound healing
films, suture material, covering for vessel
prostheses (stents), matrix for bioartificial
organs and implantates, membranes, microparticles,
etc from bio polymers are under production currently.
Biopolymers underwent tests on animals at the
Scientific Research Institute of Transplantology
and Bioartificial Organs (Ministry of Health
of the Russian Federation). Trade mark of biomaterial
- ElastoPOBtm - has been registered and clinical
trials have been started. As per specialists,
the current demand for polymers for medicine
stands at 400,000 tons pa, therefore industrial
production of destructible bioplastics is considered
economically feasible. Based on the polymer's
sale price of 95 rubles per kilogram, they have
already calculated polymer's pay-back, return
and profitability.
|