Blood oxygenators plasma

Medical applications are among the most important in the membrane market, with hemodialysis, blood oxygenators, plasma separation and fractionation being the traditional areas of applications, while artificial and bioartificial organs and regenerative medicine represent emerging areas in the field. 

Blood oxygenators Blood plasma Blood plasma extenders Blood proteins Bloodroot Blood serum... 

The fluid portion of the blood, the plasma, accounts for 55 to 60% of total blood volume and is about 90% water. The remaining 10% contains proteins (8%) and other substances (2%) including hormones, enzymes, nutrient molecules, gases, electrolytes, and excretory products. All of these substances are dissolved in the plasma (e.g., oxygen) or are colloidal materials (dispersed solute materials that do not precipitate out, e.g., proteins). The three major plasma proteins include ... 

Blood fractionation, 4 111 Blood oxygenators, 3 720 15 846 Blood plasma, 4 111 Blood plasma fractionation. See Plasma fractionation... 

One of the most important functions of blood is the binding of oxygen by haemoglobin and its transport to the tissues. Administration of blood and blood products, however, carries with it a number of risks (Table 20.3) and are not always the initial choice to replace blood or plasma loss. Blood and blood products are also expensive, have a limited availability, and a very limited shelf life. A number of alternative oxygen-carrying fluids have been developed, and some are close to release for clinical use. 

Without a reticulated structure, it would not be possible under physiological conditions to oxygenate and feed the cells. For the same reason, blood or plasma would not be able to flow through a device to take full advantage of the high surface area. In order to proceed with the technique, this mass transport problem had to be solved. 

Fig. 1 Oxygen content of the fluorocarbon emulsions Oxy-gent AF0144, Fluosol, and Perftoran as compared to fresh (a) and stored (b) blood and plasma, as a function of oxygen partial pressure.

Hetastarch is a plasma expander that produces expansion of plasma volume. It does not have oxygen-carrying capacity or contain plasma protein, so it is not a blood or plasma substitute. It is indicated as an adjunct therapy for plasma volume expansion in shock caused by hemorrhage, bums, surgery, sepsis, or other trauma and as an adjunct in leukapheresis to improve harvesting and increase yield of granulocytes. 

The blood is the body s main transport system. Although the transport and delivery of oxygen to the cells of the tissues is carried out by specialized cells, other vital components such as nutrients, metabolites, electrolytes, and hormones, are all carried in the noncellular fraction of the blood, the plasma Some components, such as glucose, are dissolved in the plasma others, for example, lipids and steroid hormones, are bound to carrier proteins for transport. The osmotic pressure of the plasma proteins regulates the distribution of water between the blood and the tissues. Plasma proteins in conjunction with platelets maintain the integrity of the circulatory system through the process of clotting. 

An important technique used in the bioartiflcial liver is based on the immobilization of the cells on the inner or outer surface of hollow fibers made of porous material. This configuration allows oxygen and other nutrients to be supplied to cells by means of a liquid stream different from the blood or plasma stream. The nutrient stream flows in the membrane side where cells are fixed, whereas blood plasma flows in the other side. The flow scheme can be co-current or counter current but usually the co-current scheme is adopted. The module is a bundle of hollow fibers contained in a cylindrical shell. A main problem to study is the level of O2 concentration in the cells at the outlet of the feed stream actually, this section is the most critical, owing to oxygen consumption along the fiber from the inlet to the outlet section. 

Polyethylene catheters were surface primed either with chromic acid solution or with oxygen plasma treatment, then dipped into a 0.6 % chitosan solution in 1 % acetic acid. After drying, the catheters were exposed to ammonia and then soaked in a pH 7.0 phosphate buffer containing 1 % heparin. About 40 yg of chitosan were deposited per square cm. The heparinization procedure added 2-3 units of heparin per square cm. This heparin can be removed by soaking in 25 % sodium chloride, however, if the heparinization is performed in the presence of sodium cyanoborohydride, the brine removes only a minor part of heparin. Negligible amounts of the coating were removed by blood at 37°C after 24 hr contact. 

For the first time already in 1898 Binz [180] showed interest in the effect of ozone on the blood and plasma and found that ozone exhibits a somnolent effect. Brinkmson and Lambert [181] proved that ozone inactivates the cell enzymes and decreases the oxygen exchange between blood and tissues. 

Blood and plasma viscosity are critical since lowered values increase oxygen delivery but decrease shear stress. Consequently, a blood substitute, beyond its effect in maintaining FCD, should be effective in preventing ischemia and apoptosis, which can be accomplished through the maintenance of adequate levels of shear stress. 

With the procedure described in the present paper there is an economical and technical approach available to produce sufficient amounts of ES-HS for large scale coating for biomaterials (e.g. implants directly exposed to blood, haemodialyzers, oxygenators, plasma separators, or catheters) to improve haemocompatibility. 

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