Hemocompatibility assay of a micro-catheter using hydrophilic coating biomaterials

For medical devices directly or indirectly contacted with blood, hemocompatibility assay is of great importance during the biological evaluation. In ISO 10993-4:2017 - Biological evaluation of medical devices part 4, a selection of tests for interactions with blood is given with the rationale for selection of tests based on their intended use specified, however, the specific testing protocols may vary significantly when performing the hemocompatibility assays. In recent years, medical catheters have been widely used in clinical practice. Moreover, a lot of surface modified catheters emerged in the market to enhance their performance of hemocompatibility especially for hydrophilic coating catheters. Unfortunately, to date, the hemocompatibility of hydrophilic coating still remains controversial due to the inherent complexity of the hemocompatibility test itself and lack of validated test methods. In this study, through determining the hemocompatibility performance for a micro-catheter with a typical hydrophilic pyrrolidone coating regarding haemolysis test, partial thromboplastin time (PTT), prothrombin time (PT) and thrombogenicity test in dogs, we have established a series of tentative hemocompatibility protocols for these tests. Hopefully, our study could not only provide some useful information for hemocompatibility evaluation on medical catheters with a hydrophilic coating but could also contribute to the development of neo-type hemocompatible medical devices for better clinical practice.