A shape memory stent of poly(ε-caprolactone-co-dl-lactide) copolymer for potential treatment of esophageal stenosis

Abstract

Biodegradable polymer stent with shape memory effect is expected to be developed in the treatment of esophageal stenosis, most likely due to traditional stents having such shortages as considerable rigidity and nondegradation. A tubular stent with the inner and outer diameters of 28 and 30 mm was manufactured from biodegradable poly(ε-caprolactone-co-DL-lactide) (PCLA) copolymer consisting of ε-caprolactone and DL-lactide at a weight ratio of 10/90. A series of tests were accomplished to investigate its properties including shape memory effects (SMEs), compression property and influence of in vitro degradation of polymer matrix on its shape recovery and dilation force. Significantly, an implantation of the stent into a dog model was performed to evaluate its function for the treatment of esophageal stenosis. The deformed stent needs about 36 s to recover its initial shape in vitro in 37°C warm water. The primary animal experiment in vivo has revealed that the implanted deformed stent could be triggered by body temperature and expectedly returned to a nearly-round shape to support esophageal wall. Therefore, the biodegradable intelligent polymer stent may be great potential to displace the conventional metallic stents for the esophageal stenosis therapy.

pH-Responsive Shape Memory Poly(ethylene glycol)–Poly(ε-caprolactone)-based Polyurethane/Cellulose Nanocrystals Nanocomposite

“…15,16 SMPs have many potential applications in the design of therapeutic strategies, 17 such as aneurysm occlusion devices, 18 esophageal stent, 19 tissue engineering scaffold, 20 and drug delivery. 21,22 Despite the demonstrated merits, the low mechanical properties of the SMPs limit their applications.…”

Responsive Biomaterials: Advances in Materials Based on Shape‐Memory Polymers

“…Such SMP-based stents have prospects for the replacement of metal alloy-based stents displaying shape-memory properties because their mechanical properties are closer to those of the tissue in which they are implanted, and preclinical experiments using dogs have successfully demonstrated their potential advantage over traditional metallic devices. [15] …”

Shape Memory Systems with Biodegradable Polyesters

“…They work aimed at enhancing the recovery stress and accelerating the shape recovery process. Stents with fast recovery at T=37 o C were also produced form poly(ε-caprolactone-co-D,L-lactide) which not only has the appropriate Ttrans but also degrades better than the reference PLA [84].…”