3D‐Printed Radiopaque Bioresorbable Stents to Improve Device Visualization

Abstract

Bioresorbable stents (BRS) hold great promise for the treatment of many life‐threatening luminal diseases. Tracking and monitoring of stents in vivo is critical for avoiding their malposition and inadequate expansion, which often leads to complications and stent failure. However, obtaining high X‐ray visibility of polymeric BRS has been challenging because of their intrinsic radiolucency. This study demonstrates the use of photopolymerization‐based 3D printing technique to fabricate radiopaque BRS by incorporating iodixanol, a clinical contrast agent, into a bioresorbable citrate‐based polymer ink. The successful volumetric dispersion of the iodixanol through the 3D‐printing process confers strong X‐ray visibility of the produced BRS. Following in vitro degradation, the 3D‐printed BRS embedded in chicken muscle maintains high X‐ray visibility for at least 4 weeks. Importantly, the 3D‐printed radiopaque BRS demonstrates good cytocompatibility and strong mechanical competence in crimping and expansion, which is essential for minimally invasive stent deployment. In addition, it is found that higher loading concentrations of iodixanol, e.g. 10 wt.%, results in more strut fractures in stent crimping and expansion. To conclude, this study introduces a facile strategy to fabricate radiopaque BRS through the incorporation of iodixanol in the 3D printing process, which could potentially increase the clinical success of BRS.

Radiopacity Enhancements in Polymeric Implant Biomaterials: A Comprehensive Literature Review

“…The treatment of obstructed body vessels involves implanting a stent into the affected vessel to reopen the blocked pathway and restore its structure. 41,76 To ensure proper positioning and detection of postoperative complications such as renarrowing of the vessel (restenosis), it is crucial for the stent to be visualized during and after implantation. 17,41,76 Bioresorbable stents were developed as an alternative to metallic stents, which often exhibited problems such as restenosis, fractures, and a need for additional surgical removal procedures.…”

“…41 However, in both cases, a rapid release of the contrast agent was observed after incubating the iodine-containing stents in phosphate-buffered saline, which was accelerated by their solubility. 41,76 The covalent bonding of iodine-containing contrast agents to the polymer backbone represents a viable strategy for longterm monitoring of biodegradable stents. 10,77 By integrating the contrast agents into the polymer chain, visualization of the stent is made possible not only during placement but also throughout the entire degradation process.…”

“…Ha et al found no adverse reaction after 8 weeks of implantation of a polycaprolactone (PCL) stent containing 15% IHX in the iliac artery of a pig model . However, in both cases, a rapid release of the contrast agent was observed after incubating the iodine-containing stents in phosphate-buffered saline, which was accelerated by their solubility. , …”

Conducting Polymer Nanoparticles with Intrinsic Aqueous Dispersibility for Conductive Hydrogels

“…Using the μCLIP printer, esophageal stents and square form factors were printed. [59] Esophageal stents were designed to be 10.93 mm long with supports and have struts 133 μm in diameter. Squares were 8 mm in length and height and were 1 mm in thickness, with 1 mm tall supports on one side to adhere prints to the platform.…”

Enabling Proregenerative Medical Devices via Citrate‐Based Biomaterials: Transitioning from Inert to Regenerative Biomaterials

“…Tissue engineering [145,191] POC-HA Bone regeneration [119,17] POC-TCP Bone regeneration [192] POC-glycerophosphate calcium (GP-Ca) Bone regeneration [126] POC-beta calcium silicate Bone regeneration [193] Silica grafted POC Bone regeneration [194] POC-gallium Bone regeneration [195] POC-Click-HA Bone regeneration [196][197] POC-M-click-HA Bone regeneration [117] POC-HA-tannic acid-silver nanoparticles Bone regeneration [118] Poly(ethylene glycol) maleate citrate (PEGMC)/HA Bone regeneration [198] PPCN-BMP9 Bone regeneration [130,199] PPCN-gelatin-BMP9 Bone regeneration [128] PPCN-SR/P/c-RGD Bone regeneration [127] BPLP-HA Bone regeneration [200] Methacrylated POC (mPOC)/HA Bone regeneration [123,201] Poly(1,8-octamethylene-citrate-co-octanol) (POCO) Cardiovascular engineering [143] POC-heparan sulfate Cardiovascular engineering [202] POC-collagen Cardiovascular engineering [203] All-trans retinoic acid (atRA)-POC Cardiovascular engineering [204] Methacrylated poly(1,12 dodecamethylene citrate) (mPDC) Cardiovascular engineering [139][140][141]205] POC-poly(acrylic acid) Wound healing [146] Poly(L-lactic acid)-poly(citrate siloxane)-curcumin polydopamine (PPCP)…”