For what water-soluble polymers are necessary?
In our imagination polymers are associated with plastic ware, the washing wall-paper and raincoats - raincoats, that is, we perceive them as the substances very resistant to effect of water. But there are also those which are dissolved in water! You are familiar for a long time with them, just did not pay attention. Well, well, we will try to tell which - that interesting and about them.
It is quite possible to make of water-soluble polymers threads and fabrics. But, apparently, who needs the clothes disappearing during a rain or a disposable bathing suit? Meanwhile, the threads which are dissolved in water are necessary. And most of all, probably, to surgeons. They apply to sewing together of wounds and a perevyazyvaniye of blood vessels “ threads “ from silk, hair, catgut suture (thin strips from veal or sheep guts). Silk and a hair do not resolve therefore seams after healing of wounds should be removed. Catgut suture independently resolves in an organism, but is frequent even before full healing of wounds.
The threads made of polymers, for example, from the polyglycoleft acid, have no these shortcomings, they are dissolved only after full scarring, and completely brought out of an organism. Accurate terms of a rassasyvaniye, lack of reaction of body tissues, durability and some other positive properties are characteristic of such threads. Therefore now about 80% of the sutural materials applied around the world - the resolving polymeric threads.
Slowly dissolved fabrics and fibers can be applied as effective dressing if chemically to connect polymer, for example, polyvinyl alcohol, to molecules of bactericidal substances. Clothes of doctors, napkins and sheets made of such fabrics completely are disinfected when wetting by water.
New medicines on the basis of water-soluble polymers even more often apply in medicine. Their main advantage - the prolonged action, that is medicine gets to an organism not at once, and gradually, throughout a certain period. It gives the chance more rare them to use, to lower a single dose. Drugs work longer time, and, happens, it is possible to deliver them to the struck body only by means of water-soluble polymers.
A striking example - medical eye films. They, unlike drops which quickly spoil also are easily washed away by tears, provide the long effect of drugs on the patient`s eyes. A basis of such films - the same water-soluble polymers. The polymeric basis of a film is dissolved in plaintive liquid, gradually releasing medicine, for example, fibrinolizin, and provides the prolonged effect of enzyme which concentration reaches a maximum in 12 hours and remains at this level within a day.
They in many cases allow to avoid injections. They should be done in that case when drugs collapse in the acid environment of a stomach. If to give to the patient “ polymeric “ a pill which does not give in to effect of gastric juice but it is willingly dissolved in the alkaline environment of intestines, drugs will be delivered to destination and without injections.
And solutions of polymers whether they are fit for something? Undoubtedly! For example, blood, this precious liquid as it sometimes is not enough! But blood is “ live “ dispersion of blood cells in plasma - water solution of biopolymers. Whether it is impossible to replace it, at least temporarily, with other polymers capable to execute the same functions? Imagine, it is possible. In 1915 - the m in practice is used to year blood substitute on the basis of gelatin. To replacement of donor blood in cardiopulmonary bypasses long time was applied by such preparations as zhelatinol. Already from the name it is visible that it is received from natural polymer too - gelatin. From fortieth years blood substitutes on the basis of a dextran and many other water-soluble polymers are used to this day. These preparations are not quite perfect, but works on creation of full-fledged blood substitutes are continued.