MIT is Utilizing PEGs in Their Fluorescent Polymer Gels & Stimuli-Responsive Smart Materials

PEGs are known for their wide use in biomedical and biotech applications including drug delivery, protein PEGylation, nanoparticle pegylation, hydrogels, regenerative medicine, etc. However, did you know that PEGs can also be used in smart materials for energy, sensor, and environmental systems? Researchers at MIT are developing fluorescent polymer gels that they hope will detect structural failure in energy equipment.

Benefits of Smart Gels & Fluorescent Polymer Gels

Have you heard of using PEGs in light-emitting polymer metallogels, coatings and films for stimuli-responsive opto-mechanical sensing applications? These smart gels and smart coatings/films could have valuable applications in structural failure sensing, infrastructure health monitoring, pH/temperature change-sensing, and amazingly the subsequent self-healing. These capabilities will be valuable in many energy and environmental systems. The availability of such self-reporting and self-healing materials would reduce the need to fabricate replacements for them over time. 

PEGylation Innovation at MIT

An MIT group developed PEG-based fluorescent polymer gels that exhibit sol-to-gel transition in response to temperature changes, pH changes, or mechanical forces, while the fluorescent emission also changes with the stimulus. They developed model light-emitting metallogels functionalized with lanthanide metal ion-ligand coordination complexes via a terpyridyl end-capped 4-Arm PEG polymer.

Essentially, 4-Arm PEG-GAS (one special type of NHS ester) was used to conjugate terpyridine to each arm terminal. These 4-arm PEG-Terpyridine polymers self-assemble or crosslink upon contact with lanthanide metal ions that exhibit different fluorescent colors from red to blue to green to white.

The MIT group investigated how the optical properties of these highly luminescent polymer networks are readily modulated by lanthanide metal ion stoichiometry, and how the dynamic nature of the lanthanide-terpyridine coordination bonding offers reversible stimuli-responsive properties of sol-gel systems and solid thin films. The metal nitrogen coordinate crosslinks have a remarkable ability to break and then re-form (self-heal), which is accompanied by changes in colors and light emission.

The PEG Products Used

The unique polymer used in this study, 4- Arm PEG-GAS, is exclusively offered by Creative PEGWorks. Check out how MIT talents used this special PEG reagent to construct their wonderful polymer gel materials!  

Interested in learning more about this landmark study at the MIT Energy Initiative? Visit MIT’s EI website to learn more about self-repairing fluorescent polymer gels!

The original paper was published in JACS, https://doi.org/10.1021/jacs.5b07394.

PEGs in the News

White-Light-Emitting Lanthanide Metallogels with Tunable Luminescence and Reversible Stimuli-Responsive Properties. It is cited more than 300 times in just a few years and the study is noted in 8 news reports.

PEG-based shape memory polymers (SMP) have broad applications in structural health, materials engineering, coating, tissue implants, medical simulation and training etc. SMP based on physical switches are those, whose responsive switches are triggered by external stimuli such as temperature, stress, light, ultrasound, humidity, chemical reagent, or combinations thereof.

SMPs based on chemical switches mainly refer to the ones based on reversible chemical reactions or reversible chemical bond; for example PEG disulfide bonds, UV-responsive acrylate bonds, diels-alder reaction, metal-nitrogen coordination bonds, redox active bonds, pH sensitive bonds including hydrazone, ester, etc. SMPs with high sensitivity, good responsive accuracy, multifunctional responsive switches, and excellent mechanical characteristics, are needed in the future.

The development of responsive switches with high-precision, quantifiable and controllable responses is critical for intelligent control in smart materials. How to design and make highly intelligent and precision SMP are ever inspired by organisms in nature that can sensitively and accurately respond to external stimuli.

Final Word: PEGs in Fluorescent Polymer Gels

There is so much to explore with PEG applications. If you’re a part of a research team, university, or biomedical company, you can trust Creative PEGWorks to deliver quality PEG products to support your work. We offer custom synthesis and can ship overnight! Explore the vast variety of PEG reagents offered at Creative PEGWorks to design and develop your shape memory polymers, smart gels, coating, and 3D or 4D printable materials, or contact us today using the form below!