Preliminary in vivo biocompatibility studies on perfluorosulphonic acid polymer membranes for biosensor applications

The first biocompatibility studies on the DuPont perfluorosulphonic acid polymer (Nafion) are presented. Presterilized samples of commercially cast and solution cast Nafion membranes were implanted subcutaneously, intraperitoneally and intravenously in male Sprague-Dawley rats. Scanning electron microscopy and histological examination of explanted samples and surrounding tissues reveal little, if any, evidence of acute or chronic foreign body inflammatory response. The fibrous capsules surrounding the implant remain nominally thin (less than 100 microns) after more than 3 months in situ, while the surrounding tissue remains well vascularized. Nafion polymer exhibits sufficient biocompatibility to make it a viable candidate for some implantable biosensor applications. It may, however, be necessary to compensate for the effect of the progression of fibrous encapsulation on sensor performance, particularly during the acute response stage.