טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentManor-Korin Naama
SubjectTrapping of Uremic Toxins
DepartmentDepartment of Chemistry
Supervisor Professor Moris Eisen
Full Thesis textFull thesis text - English Version


Abstract

Renal failure is a medical condition in which the kidneys fail to function adequately. The  kidneys play key roles in the body function, not only by filtering the blood and getting rid of waste products, but also by balancing the levels of electrolytes in the body, controlling blood pressure, and stimulating the production of red blood cells, therefore their lack of functioning leads to a very serious medical situation. The treatments given to patients suffering from renal failure are dialysis or kidney transplant. Dialysis provides an artificial replacement for lost kidney function. The dialysis procedure removes nitrogenous products of human catabolism and begins the correction of salt, water and acid-base derangements.    

Despite hemodialysis being an established treatment, the survival of dialysis patients remains poor, particularly due to increased cardiovascular risk. Different studies done in recent years indicate that more frequent and prolonged dialysis treatment is associated with remarkably improved outcomes in these patients. Therefore, there is a growing demand for true practical wearable artificial kidney (WAK) or a portable dialysis system, which will allow prolonged treatment. The blood purification in WAK systems is based on extracorporeal cleaning or on peritoneal dialysis. Different WAK systems are being developed in recent years. However, one of the problems the researchers encounter is the need for better sorbent compounds that will allow better removal of the uremic waste compounds.

In this research we wish to synthesize polymers that would be able to trap different uremic toxins. These polymers could be used in the future for the regeneration of the dialysate solution, thus providing a significant step towards the development of wearable dialysis equipment and towards treatment of uremia in general.

We were able to synthesize successfully polysulfone (PSf) and polyethersulfone (PES) modified with different functional groups, such as: aldehyde, carboxylic acid, sulfonic acid, dicarbonyl derivative, amine, etc. These polymers were characterized using a variety of methods among them: NMR, FT-IR, DSC, GPC and elemental analysis.

The different polymers were tested for trapping urea in water solution and in dialysate solution. The trapping tests were done under different conditions such as: time, pH and concentration. ortho-ether carboxylated PSf displayed the best trapping results in water and dialysate solutions, 102 and 670 g urea per 1 kg polymer, respectively.

Three additional uremic waste products were tested, creatinine, uric acid and phosphate, using different modified polysulfone. For all three uremic waste products preliminary encouraging results were obtained.