scholarly journals Effects of Sterilization on Shape Memory Polyurethane Embolic Foam Devices

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Rachael Muschalek ◽  
Landon Nash ◽  
Ryan Jones ◽  
Sayyeda M. Hasan ◽  
Brandis K. Keller ◽  
...  
Keyword(s):  
Electron Beam ◽  
Minimally Invasive ◽  
Shape Memory ◽  
Medical Devices ◽  
Biomedical Applications ◽  
Shape Memory Polymer ◽  
Thermal Characterization ◽  
Device Fabrication ◽  
Shape Memory Polyurethane

Polyurethane shape memory polymer (SMP) foams have been developed for various embolic medical devices due to their unique properties in minimally invasive biomedical applications. These polyurethane materials can be stored in a secondary shape, from which they can recover their primary shape after exposure to an external stimulus, such as heat and water exposure. Tailored actuation temperatures of SMPs provide benefits for minimally invasive biomedical applications, but incur significant challenges for SMP-based medical device sterilization. Most sterilization methods require high temperatures or high humidity to effectively reduce the bioburden of the device, but the environment must be tightly controlled after device fabrication. Here, two probable sterilization methods (nontraditional ethylene oxide (ntEtO) gas sterilization and electron beam irradiation) are investigated for SMP medical devices. Thermal characterization of the sterilized foams indicated that ntEtO gas sterilization significantly decreased the glass transition temperature. Further material characterization was undertaken on the electron beam (ebeam) sterilized samples, which indicated minimal changes to the thermomechanical integrity of the bulk foam and to the device functionality.

scholarly journals Shape Memory Polymer-Based Insertable Electrode Array towards Minimally Invasive Subdural Implantation

2021 ◽  
pp. 1-1
Author(s):  
Anastasiia Kravtcova ◽  
Antoniya Toncheva ◽  
Samuel Rantataro ◽  
Emilia Peltola ◽  
Jean-Marie Raquez ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Electrode Array

Shape-Memory Polymer Medical Devices

2019 ◽  
pp. 394-405
Author(s):  
Muhammad Y. Razzaq ◽  
Markus Reinthaler ◽  
Mark Schröder ◽  
Christian Wischke ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Medical Devices ◽  
Shape Memory Polymer

scholarly journals Isocyanate Modified GO Shape-Memory Polyurethane Composite

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 118 ◽  
Author(s):  
Yuanchi Zhang ◽  
Jinlian Hu
Keyword(s):  
Graphene Oxide ◽  
Minimally Invasive ◽  
Shape Memory ◽  
Bone Repair ◽  
Recovery Process ◽  
Invasive Treatment ◽  
Element Analysis ◽  
Polyurethane Composite ◽  
Shape Memory Effects ◽  
Shape Memory Polyurethane

Shape-memory composites have benefits for minimally invasive surgery, but their wider applications for bone repair are hindered by conflicts between the mechanical and memory performances, especially at load-bearing locations. In this study, we fabricated a graphene oxide shape-memory polyurethane composite through the chemical combination of graphene oxide and isocyanate, in order to realize satisfactory mechanical and shape-memory effects. As desired, a modulus of ~339 MPa and a shape recovery ratio of 98% were achieved, respectively, in the composite. In addition, finite element analysis demonstrated that, after being implanted in a defective bone through a minimally invasive treatment, where the highest stress was distributed at the implant–bone interface, this composite could offer a generated force during the recovery process. Furthermore, we also discuss the origins of the improved mechanical and memory properties of the composites, which arise from increased net-points and the stable molecular structure inside. Therefore, with its superior structure and properties, we envision that this shape-memory composite can provide new insights toward the practical application of shape-memory polymers and composites in the field of bone repair.

scholarly journals Chemical Modifications of Porous Shape Memory Polymers for Enhanced X-ray and MRI Visibility

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4660
Author(s):  
Grace K. Fletcher ◽  
Landon D. Nash ◽  
Lance M. Graul ◽  
Lindy K. Jang ◽  
Scott M. Herting ◽  
...  
Keyword(s):  
Shape Memory ◽  
Medical Devices ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Tissue Scaffolds ◽  
Resonance Imaging ◽  
Clinical Imaging ◽  
X Ray ◽  
Device Development ◽  
Magnetic Resonance Imaging Mri

The goal of this work was to develop a shape memory polymer (SMP) foam with visibility under both X-ray and magnetic resonance imaging (MRI) modalities. A porous polymeric material with these properties is desirable in medical device development for applications requiring thermoresponsive tissue scaffolds with clinical imaging capabilities. Dual modality visibility was achieved by chemically incorporating monomers with X-ray visible iodine-motifs and MRI visible monomers with gadolinium content. Physical and thermomechanical characterization showed the effect of increased gadopentetic acid (GPA) on shape memory behavior. Multiple compositions showed brightening effects in pilot, T1-weighted MR imaging. There was a correlation between the polymeric density and X-ray visibility on expanded and compressed SMP foams. Additionally, extractions and indirect cytocompatibility studies were performed to address toxicity concerns of gadolinium-based contrast agents (GBCAs). This material platform has the potential to be used in a variety of medical devices.

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