A dual‐induced self‐expandable stent based on biodegradable shape memory polyurethane nanocomposites (PCLAU/Fe₃O₄) triggered around body temperature

Abstract

Concerning the occurrence of in‐stent restenosis and stent thrombosis of stent implantation with balloon angioplasty, a dual‐induced self‐expandable stent based on biodegradable shape memory polyurethane nanocomposites (PCLAU/Fe3O4) was developed. The stent could maintain its temporary shape at body temperature for a certain period of time while it was able to recover to its permanent shape at the temperature a little above body temperature (around 40 °C) in both a water bath and an alternating magnetic field. The trigger temperature and remote local heating ensured enough operation time and harmless activation without heating the body tissue. The nanocomposites had high fixing ratios above 99% and recovery ratios above 82% at both 37 and 40 °C. Cytotoxicity and in vitro degradation showed the nanocomposites had good biocompatibility and biodegradability. The PCLAU/Fe3O4 nanocomposites with dual‐responsive shape memory effects, desirable mechanical properties, biocompatibility, and biodegradability show great potential for vascular stents. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45686.

Degradation and stabilization of polyurethane elastomers

“…Biodegradable PUs have recently attracted much attention due to concerns about environmental accumulation and the need to develop new materials for biomedical applications[583][584][585]. For such PUs, the macrodiols (polymers or copolymers) or ChExs used are based on ingredients that are inherently biodegradable, such as: PCL[456,474,478,543,, PLA[598,601,605,606,608,[616][617][618][619][620][621], plant oils…”

Experimental and modeling investigation of shape memory behavior of polyurethane/carbon nanotube nanocomposite

“…This behavior is similar to some other studies. For example, Gu et al reported that mechanical properties of biodegradable SMPU were improved with the addition of Fe 3 O 4 to 6 wt.% filler, and an opposite effect was observed at higher content.…”

Wearable and Implantable Devices for Cardiovascular Healthcare: from Monitoring to Therapy Based on Flexible and Stretchable Electronics

“…Since systemic release is minimal compared to taking these medicines, the risk of toxicity is reduced . Another approach is to fabricate stents out of biodegradable materials as an alternative to permanent stents, because stents are only needed temporarily and the presence of a stent strut may cause long‐term complications such as late thrombosis (Figure a, second right) . There has been a first attempt of the patient‐specific customization of biodegradable stents using 3D imaging and 3D printing technology (Figure b, left) .…”