More biocompatible electrochemical sensors using nitric oxide release polymers

The response characteristics and biocompatibilily of potentiometric ion-sel ective electrodes (ISEs) and amperometric oxygen sensors prepared with vari ous polymeric materials that spontaneously release nitric oxide (NO) are ex amined. Plasticized polymer films (polyurethane and poly(vinyl chloride)) f ormulated with three distinctly different types of diazeniumdiolate NO dono rs are shown to release NO for extended periods time of time ( > 48 h) whil e also exhibiting a dramatic decrease in platelet adhesion and activation b oth in vitro and in vivo. Potentiometric ISEs for pH and K+ prepared by dop ing these NO release polymeric materials with appropriate ionophores (trido decylamine and valinomycin, respectively) display the same analytical respo nse properties (slope and selectivity) as conventional electrodes without N O release capability Similarly, it is shown that NO release polymer films c an be utilized as outer gas permeable membranes for construction of Clark s tyle amperometric oxygen sensors without alternating the oxygen sensitivity and response times of such devices. It is concluded that the use of NO rel ease polymers to fabricate catheter style electrochemical sensors may be th e solution to lingering biocompatibility and concomitant performance proble ms encountered when trying to employ these sensors for continuous intravasc ular measurements of blood gases and electrolytes.