Plasma etching elevates iohexol-loading capacity of poly(p-dioxanone) for X-ray opaque cardiac occluders

Structural heart diseases are one of the leading health issues. While polydioxanone (PPDO) cardiac occluders can treat this condition, their lack of X-ray visibility makes it challenging to determine device placement during surgery, thereby increasing the risk of complications. Herein, plasma etching (PE) is performed to fabricate micro/nanostructures and introduce active groups on the surface of PPDO occluders, increase the loading of the iohexol (IHX) contrast agent, and prevent rapid detachment. The plasma conditions are optimized to achieve maximum surface roughness. Experimental results show that after plasma etching for 30 min, the PPDO surface can be loaded with up to 14.5 mg/cm². After immersion in the simulated body fluid for 4 h, the grayscale value of the digital subtraction angiography for the IHX-loaded PPDO remains below 100. The PPDO-PE-IHX also exhibits sufficient in vivo X-ray imaging capacity and biosafety. Plasma treatment can improve X-ray imaging without compromising mechanical strength and maintaining the main chemical composition of the occluder, consequently improving diagnostics and success rates in interventional cardiac surgeries.