by Marina MALYGINA, journalist

A new plant for production of membrane filters based on nanotechnologies was founded in the territory of the Dubna technical and special economic zone near Moscow in July 2010. Within 2.5 years a modern Beta complex will be constructed here for mass output of a product unparalleled in the world, namely, 1.5 mln instruments for cascade plasmapheresis (blood purification) annually.

This equipment can provide nanofiltration of blood plasma components right up to individual protein molecules and is designed, first of all, for treatment of atherosclerosis, ischemic disease, stenocardia and cardiac failure. About 1.5 mln people suffering from such diseases die in Russia annually, and approximately 12 mln patients need therapy by means of plasmapheresis.

It should be noted that in Japan, Germany, Italy and other highly developed countries, this procedure has for long become routine though not cheap, as the instruments necessary for it are based on expensive hollow-fiber technology. But Russian scientists from the Joint Institute for Nuclear Research and the Institute of Crystallography of the Russian Academy of Sciences (Moscow) have developed a new method of segregation of blood components using flat track membranes. The latter are produced by bombardment of a thin lavsan film by inert gas ions driven at high speed by an accelerator*. In the places "penetrated" by the ion, peculiar channels of radiation damage without a through opening are formed–the so-called tracks. The following procedures, i.e. ultraviolet treatment and chemical etching, form through pores from them, invisible to the eye–up to 70 mln per 1 sq. cm. By changing temperature, concentration or time of treatment by chemicals, we can assign a necessary size to them varying the diameter within a range of several orders. It is just such lavsan film 10 µm thick that serves as a base for national membrane plasmofilters.

The film was first used in Dubna with an active participation of Academician Georgy Flerov back in the 1970s. At that time microelectronics, which needed filtration of high-purity medium, took interest in this high-tech product. Early in the 1980s, the Laboratory of Nuclear Reactions produced dozens of thousands of square meters of track membranes annually for 200 profile enterprises of the USSR. Thin technologies were used for medical needs since 1998, when Trackpore Technology company was set up, which implemented in 2001 its first project, i.e. Alpha Research and Production Complex for production of the 400 Nm pore diameter polymer film. Since then its products, namely, HemoFenix instruments and Rosa filters with European certificates, are in high demand both in Russia and

* See: A. Sissakian, "Dubna's Worldwide Glory", Science in Russia, No. 2, 2006.–Ed.

abroad (in the CIS countries and markets of a number of East European states).

At present Trackpore Technology in cooperation with Rosnano, a Russian nanotechnology corporation, which invested 1.29 bln rubles into the project, is building a Beta plant, where a new generation of instruments for more careful blood purification will be produced. The cascade filtration system is realized in them. At first, plasma as a main carrier of viruses and antibodies will be separated from blood by means of membranes with 400 Nm pores and then purified through filters with 20-100 Nm openings.

According to experts, the suggested technology will abruptly reduce the cost of plasmapheresis and make this service more accessible to public at large. Today a set of disposable parts, including a filter, purchased abroad costs from 15,000 to 35,000 rubles. But a patient pays for it 30,000 to 50,000 rubles. After the national product appears in the market, the expenses of patients who need cascade plasmapheresis will decrease several times. "Our objective," says Vyacheslav Terentyev, General Director of Trackpore Technology, "is to bring the cost of the set to the level of 3,000-5,000 rubles by 2014, and this, naturally, will affect also the cost of the service". It means that this procedure will become available to many people and appear in hundreds of country clinics. Instruments and filters comparable in efficiency and safety with existing foreign analogs are now in demand in other countries too. Already today Dubna is receiving letters of inquiry from the CIS countries, France, Switzerland, India and China.

Creation of nanomembranes is a supercomplex problem. To solve it, specialists of the Laboratory of Nuclear Reactions named after Flerov (Joint Institute for Nuclear Research), Director Sergei Dmitriev, Dr. Sc. (Phys. & Math.), are constructing a special accelerator, which will become the "heart" of the Beta plant. The first industrial cyclotron used for commercial pur-

poses in the Alpha complex irradiates 100 sq.m of film per hour. Capacity of the new accelerator will be almost 5 times higher, and it will process up to 1 mln sq.m of track membranes annually.

It is planned to start large-scale production of the equipment for cascade plasmapheresis in 2013, and by 2014 the enterprise with 550 workers will be up and running at full capacity, i.e. 800,000 filters annually.

In anticipation of a new line, the Department of Perspective Works of Trackpore Technology is engaged in perfection of instruments and filters to expand a range of procedures using them and mastering hemosorption, plasmosorption and other methods of blood purification. The Dubna innovators are convinced that modification of the systems will promote "conquering" of an extensive market of blood donation, several times larger as compared with conventional plasmapheresis. There are also other daring ideas, i.e. to go beyond the limits of medical application of track membranes–for example, to use them for purification of aviation fuel, gases, water and juices.