Mechanical bionic compression resistant fiber/hydrogel composite artificial heart valve suitable for transcatheter surgery

The heart valve is a key structure for human blood circulation, and the development of artificial heart valves (AHVs) has become one of the research hotspots in the field of cardiovascular diseases. Compared to the vulnerability of biological valves to compression damage in transcatheter aortic valve replacement surgery (TAVR), polymer valves have shown superior performance in research. However, its structural differences from natural valves have limited its development. In this study, polycaprolactone gelatin (PCL-Gel) co-spinning directional nanofibers (FIB) were used to construct a three-layer structure of orientation layer-random layer-orientation layer imitating natural valves. Then, PCL-Gel/PAAm-co-PAA-Fe composite (COM-Fe) was prepared by iron ion crosslinking the oriented fiber membrane wrapped by polyacrylamide polyacrylic acid copolymer hydrogel (COM). The COM-Fe material has anisotropy similar to that of native valves and fully meets the thickness requirements for transcatheter surgery. In vitro simulated compression results showed that the COM-Fe material has no significant structural or strength loss after short-term curling compression. In vitro fluid dynamics results showed that the COM-Fe samples could fully achieve the parameters specified in ISO 5840-3:2021. In addition, COM-Fe materials showed excellent biocompatibility both in vitro and in vivo, and demonstrated anti-inflammation potential in a rat subcutaneous embedding model. It can be seen that biomimetic COM-Fe composite materials with good curling compression resistance and valve function have great potential for application in the direction of transcatheter AHVs.