An anticoagulant/hemostatic indwelling needle for oral glucose tolerance test

Indwelling needles are widely used in the clinic for their advantages of reducing the pain and discomfort caused by repeated venipuncture. Achieving anticoagulation and hemostasis with one single indwelling needle is highly desired from perspective of implantation patency and the prevention of needle-withdrawal-induced uncontrolled bleeding. Herein, we develop a sophisticated indwelling needle with an anticoagulant/hemostatic dual function by anchoring an anticoagulant heparin coating and a hemostatic hydrogel coating on the inner surface and the outer surface of the indwelling needle, respectively. The results of in vitro tests and continuous blood collections from the rabbit ear vein indicate that the anticoagulant coating can resist the adhesion of proteins and blood cells, and its anticoagulant effect can maintain the patency of the indwelling needle for 3 hours after implantation. Meanwhile, the xerogel-hydrogel transition of the hemostatic coating upon contacting blood promotes the aggregation of blood cells, thus sealing the puncture site to achieve complete hemostasis after needle removal. Importantly, this anticoagulant/hemostatic indwelling needle can replace traditional repeated puncture, and can be used to monitor blood glucose concentration changes in diabetic rats through continuous blood collection, portending its promising application in the oral glucose tolerance test.