Preclinical study of a self-expanding pulmonary valve for the treatment of pulmonary valve disease

In the past decade,balloon-expandable percutaneous pulmonary valves have been developed and applied in clinical practice.However,all the existing products of pulmonary artery interventional valves in the market have a straight structure design,and they require a preset support frame and balloon expansion.This shape design of the valve limits the application range.In addition,the age of the population with pulmonary artery disease is generally low,and the existing products cannot meet the needs of anti-calcification properties and valve material durability.In this study,through optimization of the support frame and leaflet design,a self-expanding pulmonary valve product with a double bell-shaped frame was designed to improve the match of the valve and the implantation site.A loading and deployment study showed that the biomaterial of the valve was not damaged after being compressed.Pulsatile flow and fatigue in vitro tests showed that the fabricated pulmonary valve met the hydrodynamic requirements after 2108 accelerated fatigue cycles.The safety and efficacy of the pulmonary valve product were demonstrated in studies of pulmonary valve implantation in 11 pigs.Angiography and echocardiography showed that the pulmonary valves were implanted in a good position,and they had normal closure and acceptable valvular regurgitation.The 180 days’implantation results showed that the calcium content was 0.31-1.39 mg/g in the anti-calcification treatment group,which was significantly lower than that in the control valve without anti-calcification treatment(16.69 mg/g).Our new interventional pulmonary valve product was ready for clinical trials and product registration.

Functional non-glutaraldehyde treated porcine pericardium for anti-coagulation,anti-calcification,and endothelial proliferation bioprosthetic heart valves

In the last decade,the number of transcatheter heart valve replacement for severe heart valve disease has increased exponentially.Although the bioprosthetic artificial heart valve(BHV)has similar fluid dynamics performance to the original heart valve compared with mechanical heart valve so that there is no need to take long-term anticoagulant drugs to prevent thromboembolism,transcatheter BHV replacement are still at risk for thrombosis during the first few months according to the clinical data.However,the use of antithrombotic drugs can also increase the risk of bleeding.Therefore,it is particularly important to improve the anticoagulant properties for the BHV itself.In this work,a kind of non-glutaraldehyde cross-linked BHV material with excellent antithrombotic ability has been prepared from carboxylated oxazolidine treated porcine pericardium(consisting of collagen,elastin and glycoprotein)with the further graft of the anticoagulant heparin sodium via hydrophilic modified chitosan.Along with the similar mechanical properties and collagen stability comparable to the glutaraldehyde cross-linked porcine pericardium(PP),these functional non-glutaraldehyde cross-linked PPs exhibit better biocompatibility,promoted endothelial proliferation and superior anti-calcification ability.More importantly,excellent anticoagulant activity can be observed in the hematological experiments in vivo and in vitro.In summary,these excellent performances make these functional non-glutaraldehyde cross-linked PPs great potentialities in the BHV applications.