4D Printing of Overall Radiopaque Customized Bionic Occlusion Devices

Abstract

Percutaneous closure of ventricular septal defect (VSD) can effectively occlude abnormal blood flow between ventricles. However, commonly used Nitinol occlusion devices have non-negligible limitations, such as nondegradability leading to life-threatening embolization; limited device size predisposing to displacement and wear; only a few radiopaque markers resulting in inaccurate positioning. Nevertheless, the exploration of customized, biodegradable, and overall radiopaque occluders is still vacant. Here, overall radiopaque, biodegradable, and dynamic reconfigurable 4D printed VSD occluders are developed. Based on wavy bionic structures, various VSD occluders are designed and manufactured to adapt to the position diversity of VSD. The customized configuration, biocompatibility, and biodegradability of the developed 4D printed bionic occluders can eliminate the series of complications caused by traditional occluders. The overall radiopacity of 4D printed VSD occluders is validated ex vivo and in vivo, whereby accurate positioning can be assured. Notably, the preparation strategies for 4D printed occluders are scalable, eliminating the barriers to mass production, and marking a meaningful step in bridging the gap between modeling and clinical application of 4D printed occlusion devices. This work opens attractive perspectives for the rapid manufacturing of customized intelligent medical devices for which overall radiopacity, dynamic reconfigurability, biocompatibility, and biodegradability are sought.

Recent Development of Biodegradable Occlusion Devices for Intra-Atrial Shunts

“…Recently, Lin C et al . [ 142 ] developed a biodegradable, dynamic reconfigurable 4D printed customized bionic VSD occluder, which was made of shape memory polyethylene glycol (PEG)/PLA biocomposites with capability of shape transformation at near body temperature. In order to realize its visuality under X-ray, radiopaque fillers were introduced into the PEG/PLA matrix.…”

4D Printing for Biomedical Applications

“…4D printing technology provides a groundbreaking avenue to address these challenges by enabling the fabrication of personalized, high-precision occlusion devices. [52] Specifically, 4D printed occlusion devices have proven their efficacy in closing atrial septal defects with enhanced treatment accuracy [52,304] (Figure 5ci,ii [52] and Figure 5ciii [53] ). These devices often incorporate SMPs, as evidenced in a study where a 4D printed device consisting of a supporting frame made from a PLA/Fe 3 O 4 composite was demonstrated.…”

Smart implants: 4D-printed shape-morphing scaffolds for medical implantation

“…Meanwhile, a uniform distribution of aligned cells and excellent myocardial maturation on 4D-curved cardiac constructs were observed ( Figure 8D ). Beyond these, 4D-printed thermo-responsive SMP stents can be used for the repairment of cardiac defects, such as ventricular 327 septal defect (VSD) [ 140 ] and atrial septal defect (ASD) ( Figure 8C ) [ 112 ] .…”