Feasibility assessment of parathyroid hormone adsorption by using polysaccharide-based multilayer film systems

Chronic kidney disease (CKD) is a systemic disorder that combines complex bone and mineral abnormalities. The high level of parathyroid hormone (PTH) in the blood causes irreversible renal dysfunction and cardiovascular disease. Therefore, it is necessary to reduce level of PTH in the blood of patients with uremic state. In this study, chitosan and heparin were chosen to form polysaccharide-based multilayer films based on their antibacterial ability, good biocompatibility and hemocompatibility. In addition, a previous study has revealed that PTH is a heparin/polyanion binding protein because of the similarity of heparin to the cell surface proteoglycans. Subsequently, the surface properties including thickness, surface hydrophobicity and surface charge of a series of multilayer films were analyzed. The PTH adsorption rate of a series of multilayer films was also assessed. The results revealed that the optimizing condition is (CHI/HEP)_2.5 and 60 min in both PBS only and PBS with the addition of bovine serum albumin, which demonstrated the specific adsorption of PTH on the materials. Furthermore, the hemolysis test also revealed that (CHI/HEP)_2.5 shows good blood compatibility. It is considered that polysaccharide-based multilayer films may provide an alternative for the surface modification of hemodialysis membranes and equipment.