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Updated: Jun 20, 2026
Biofunctionalized Prussian Blue Nanoparticles for Multimodal Molecular Imaging Applications
Published on: April 28, 2015
Biodegradable polyphosphoester micelles act as both background-free 31P magnetic resonance imaging agents and drug
Olga Koshkina1, Timo Rheinberger2, Vera Flocke3
1Sustainable Polymer Chemistry Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands. o.koshkina@utwente.nl.
Abstract:
In vivo monitoring of polymers is crucial for drug delivery and tissue regeneration. Magnetic resonance imaging (MRI) is a whole-body imaging technique, and heteronuclear MRI allows quantitative imaging. However, MRI agents can result in environmental pollution and organ accumulation. To address this, we introduce biocompatible and biodegradable polyphosphoesters, as MRI-traceable polymers using the 31P centers in the polymer backbone. We overcome challenges in 31P MRI, including background interference and low sensitivity, by modifying the molecular environment of 31P, assembling polymers into colloids, and tailoring the polymers' microstructure to adjust MRI-relaxation times. Specifically, gradient-type polyphosphonate-copolymers demonstrate improved MRI-relaxation times compared to homo- and block copolymers, making them suitable for imaging. We validate background-free imaging and biodegradation in vivo using Manduca sexta. Furthermore, encapsulating the potent drug PROTAC allows using these amphiphilic copolymers to simultaneously deliver drugs, enabling theranostics. This first report paves the way for polyphosphoesters as background-free MRI-traceable polymers for theranostic applications.
Insights
Researchers developed novel MRI-traceable polymers using polyphosphoesters for background-free imaging. These biodegradable materials enable in vivo monitoring and drug delivery, paving the way for advanced theranostics.
Area of Science:
- Polymer Chemistry
- Biomaterials Science
- Medical Imaging
Background:
- In vivo polymer monitoring is essential for drug delivery and tissue regeneration.
- Magnetic Resonance Imaging (MRI) offers whole-body imaging, but conventional agents cause pollution and accumulation.
- Heteronuclear MRI provides quantitative imaging but faces challenges like background interference and low sensitivity.
Purpose of the Study:
- To introduce biocompatible and biodegradable polyphosphoesters as MRI-traceable polymers.
- To overcome limitations of 31P MRI for improved sensitivity and background-free imaging.
- To enable theranostic applications through simultaneous drug delivery and imaging.
Main Methods:
- Synthesized polyphosphoesters with 31P centers in the polymer backbone.
- Modified the molecular environment of 31P and assembled polymers into colloids.
- Tailored polymer microstructure, focusing on gradient-type polyphosphonate-copolymers, to optimize MRI-relaxation times.
Main Results:
- Demonstrated background-free 31P MRI imaging and biodegradation in vivo (Manduca sexta).
- Gradient-type polyphosphonate-copolymers showed improved MRI-relaxation times compared to other architectures.
- Successfully encapsulated PROTAC drugs within amphiphilic copolymers for simultaneous drug delivery.
Conclusions:
- Polyphosphoesters offer a promising platform for background-free, MRI-traceable polymers.
- These materials are suitable for in vivo monitoring, biodegradation studies, and theranostic applications.
- This work establishes a foundation for developing advanced polyphosphoester-based theranostic systems.
