Atrial septal defect(ASD)is one of the major congenital heart diseases,and transcatheter closure with a cardiac occluder is a modern method to treat ASD with the advantage of mini-invasiveness over traditional surgica...Atrial septal defect(ASD)is one of the major congenital heart diseases,and transcatheter closure with a cardiac occluder is a modern method to treat ASD with the advantage of mini-invasiveness over traditional surgical closure.While current occlu-sion devices are mainly made of non-degradable nitinol with superelasticity,the permanent existence of a metal in vivo may trig-ger potential complications and especially has an adverse effect on the heart development for children.However,it is challenging to in-vent a superelasticity-free occluder that can be delivered through a catheter but firmly locked after being opened at the target site;it is also much desired for research and development to quickly assess the feasibility of a superelasticity-free occluder in vitro.Herein,a biodegradable poly(L-lactide)(PLLA)occluder composed of a braided PLLA frame as the skeleton and a nonwoven PLLA fabric as the flow-blocking membrane is developed,and a controllable locking structure is designed to enable firm closure for a device even without superelasticity.We also suggest and justify a series of in vitro methods to assess the efficacy of the biodegradable occluder,and the results confirm the reliability of locking,water-blocking,mechanical strength and degrad-ability.It is found that the PLLA fabric with moderate fiber density is optimal for surface endothelialization.We also carry out biological assessments;significant endothelialization and alleviated inflammation response are observed after 6 months of subcutaneous implanta-tion into rabbits.The porcine model illustrates that the biodegradable polymeric occluder can be successfully implanted into the atrial septum via transcatheter intervention;the follow-ups have confirmed the safety and efficacy of this biodegradable polymeric occluder with the controllable locking structure.展开更多
基金supported by the National Key R&D Program of China(grant no.2023YFC2410300)the National Natural Science Foundation of China(grant no.52130302).
文摘Atrial septal defect(ASD)is one of the major congenital heart diseases,and transcatheter closure with a cardiac occluder is a modern method to treat ASD with the advantage of mini-invasiveness over traditional surgical closure.While current occlu-sion devices are mainly made of non-degradable nitinol with superelasticity,the permanent existence of a metal in vivo may trig-ger potential complications and especially has an adverse effect on the heart development for children.However,it is challenging to in-vent a superelasticity-free occluder that can be delivered through a catheter but firmly locked after being opened at the target site;it is also much desired for research and development to quickly assess the feasibility of a superelasticity-free occluder in vitro.Herein,a biodegradable poly(L-lactide)(PLLA)occluder composed of a braided PLLA frame as the skeleton and a nonwoven PLLA fabric as the flow-blocking membrane is developed,and a controllable locking structure is designed to enable firm closure for a device even without superelasticity.We also suggest and justify a series of in vitro methods to assess the efficacy of the biodegradable occluder,and the results confirm the reliability of locking,water-blocking,mechanical strength and degrad-ability.It is found that the PLLA fabric with moderate fiber density is optimal for surface endothelialization.We also carry out biological assessments;significant endothelialization and alleviated inflammation response are observed after 6 months of subcutaneous implanta-tion into rabbits.The porcine model illustrates that the biodegradable polymeric occluder can be successfully implanted into the atrial septum via transcatheter intervention;the follow-ups have confirmed the safety and efficacy of this biodegradable polymeric occluder with the controllable locking structure.
