Author/Editor     Milošev, I
Title     Effect of complexing agents on the electrochemical behaviour of orthopaedic stainless steel in physiological solution
Type     članek
Source     J Appl Electrochem
Vol. and No.     Letnik 32
Publication year     2002
Volume     str. 311-20
Language     eng
Abstract     This work is aimed at providing a better understanding of the biocompatibility of stainless steel in the human body, where various biomolecules are able to bind metal ions and convey them from the surface of an orthopaedic implant to various parts of the body. The passivation behaviour of orthopaedic stainless steel was studied by potentiodynamic and potentiostatic electrochemical methods in physiological solution as a function of type and concentration of complexing agents added. The latter were used to simulate the complexing effect of biomolecules in vitro. Two complexing agents, EDTA and citrate, were investigated in the concentration range from 0.1 to 100 mM. Their addition induces a pronounced effect on the passivation characteristics of stainless steel. The results were discussed in the context of the formation of soluble complexes of metal ions, which induces an increase in metal dissolution and disturbs the formation of the passive layer. The degree of increased dissolution appears to be related to the stability constants of the complex formed.
Descriptors     BIOCOMPATIBLE MATERIALS
STAINLESS STEEL
IMPLANTS, ARTIFICIAL
EDETIC ACID
CITRATES
POTENTIOMETRY
CORROSION
BUFFERS