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Updated: Feb 5, 2026
10:53
Shape Memory Polymers for Active Cell Culture
Published on: July 4, 2011
13.9K
Polyurethane Microparticles for Stimuli Response and Reduced Oxidative Degradation in Highly Porous Shape Memory
A C Weems1, W Li2, D J Maitland1
1Department of Biomedical Engineering , Texas A&M University , College Station , Texas 77840 , United States.
ACS Applied Materials & Interfaces
|September 6, 2018
Summary
Incorporating antioxidants into microparticles enhances shape memory polymer (SMP) biostability and oxidative resistance for medical uses. This strategy improves material lifespan and functionality in degradation environments.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Medical Device Engineering
Background:
- Shape memory polymers (SMPs) show promise for medical applications but face challenges with degradation and mass loss.
- Oxidation of amino-alcohol-based SMPs can lead to functional loss and potential toxicity.
- Tailoring SMP properties like gravimetric changes is crucial for clinical translation.
Purpose of the Study:
- To control gravimetric changes in SMPs for improved stability and functionality.
- To investigate the impact of antioxidant incorporation methods on SMP properties.
- To enhance the oxidative resistance and lifespan of SMPs for medical applications, specifically aneurysm occlusion.
Main Methods:
- Incorporation of small molecule antioxidants directly into the polymer matrix.
- Formation of SMP composite materials by including antioxidants within microparticles.
- Assessment of thermomechanical properties, strain recovery, elastic modulus, and strain to failure.
- Evaluation of oxidative stability under accelerated conditions and simulated in vivo environments (porcine aneurysms).
- Demonstration of environmental sensing capabilities (pH-dependent fluorescence) and payload release.
Main Results:
- Direct antioxidant incorporation reduced strain recovery and altered mechanical properties.
- Antioxidants in microparticles maintained 100% shape recovery and improved thermomechanical stability.
- Microparticle composites significantly increased oxidative resistance, extending material lifespan beyond 1000 days in a porcine aneurysm model.
- Polyurethane-urea microparticles in porous SMPs increased biostability by approximately 25%.
- Microparticle composites demonstrated pH-dependent fluorescence and controlled antioxidant release.
Conclusions:
- Antioxidant incorporation in microparticles is a superior strategy for enhancing SMP biostability and oxidative resistance compared to direct incorporation.
- Microparticle composite SMPs offer tailorable properties, extended lifespan, and potential for environmental sensing, making them suitable for medical applications like aneurysm occlusion.
- This approach addresses critical challenges in SMP clinical translation related to degradation and functionality retention.
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