Preparation and characterization of air sprayed silk fibroin/silica-based thermal-insulation coatings on catheters for cerebral hypothermia therapy

Clinical practice of therapeutic hypothermia for neuroprotection in acute cerebral ischemia has been hindered by warming effect on the cold infusate along pathway, which results from the poor thermal resistance of traditional interventional catheter. In this study, thermal insulation coatings with different spray parameters and coating suspension compositions were prepared via air-spraying on Nylon substrate for biomedical application. The surface morphology and microstructure of coatings were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), respectively. Silk fibroin (SF) and hollow silica based nanospheres (HSBNS) were successfully sprayed on Nylon substrate. The thermal conductivity of coating measured by light flash apparatus is down to 0.00105 W/(m·K). The tape test indicates that coatings containing SF, HSBNS and glyceryl have good adhesion which is a promising method to enhance the thermal insulation performance of traditional catheter for cerebral hypothermia therapy.