To celebrate the growth and development of the RSC Applied Polymers community and to highlight the remarkable authors who continue to contribute their high quality work to the journal, we would like to share the opinions and insights of these authors through this introductory blog post. Once dubbed #RSCAppliedfirst50, our blog posts aim to give a voice to the authors behind the research and hope that their insights might shed light upon growing challenges and progress in polymer science and its applications.
In this edition, we hear from Maryam Behzad Khoshgoee, Mithun Kumar Debnath, Griffin Pardo, Yichun (Lucia) Yuan, Muhammad Zeeshan, Erqian Mao, Burcu (Eksioglu) Gurkan, Matthew Bertin and Metin Karayilan as they discuss their recently published article, ‘Multi-responsive polymers with degradable side-chain functionality for controlled hydrolysis and tunable thermal transition‘.
Programmable by Design: Polymers That Respond to Heat and Time
A new family of multi-responsive polymers offers a tunable platform for injectable biomedical materials.
What if a material could be designed to flow easily during an injection, stay put once it’s in place, and then gradually transform and clear from the body on a schedule you set in advance? That’s the kind of control we set out to build into a new family of stimuli-responsive polymers.
Stimuli-responsive polymers are an exciting class of “smart” materials that change their properties in response to their surrounding environment. In our recent study, we developed a new family of multi-responsive polymer systems designed to react to two triggers at once: temperature and hydrolysis. We prepared these materials by incorporating hydrolyzable lactone or cyclic carbonate side chains into thermoresponsive PEG-based terpolymers using RAFT polymerization. By carefully tuning the polymer composition, we could dial in key properties, including cloud point temperature, viscosity, degradation behavior, and release profile, all within the physiologically relevant 25–37 °C window.
Why polymers, and why two triggers?
Polymers are central to this application because their molecular structure can be designed to govern how a material behaves before, during, and after injection. In our system, ethylene glycol–based methacrylate units drive temperature-induced changes near body temperature, while the degradable side chains add a second layer of control through hydrolysis. As the lactone or cyclic carbonate groups hydrolyze, the polymer grows more hydrophilic, shifting its solubility, thermal transition, and viscosity over time. That combination is especially appealing for injectable biomedical materials, where an ideal formulation should be easy to administer, remain localized after injection, and gradually change or clear away.
Lactone vs. cyclic carbonate: a head-to-head comparison
A key highlight of the study is the direct comparison between lactone- and cyclic carbonate–containing terpolymers. Both systems showed tunable thermal transitions and hydrolysis-driven shifts in cloud point temperature, but the cyclic carbonate polymers hydrolyzed faster and showed lower viscosity (and lower glass transition temperatures) than their lactone counterparts. Those traits make the cyclic carbonate systems particularly promising for minimally invasive injectable applications. Density functional theory calculations backed up what we saw experimentally, revealing distinct transition-state geometries and confirming that cyclic carbonate ring-opening is kinetically favored. The polymers also exhibited radiofrequency-induced heating, pointing to the potential for remote, on-demand triggering of their thermal transitions.
Putting it to the test
To probe the biomedical relevance of these materials, we ran injectability and dye-release experiments. In tissue-mimicking agarose gels, the polymer formulations stayed more localized than dye alone, suggesting they can slow diffusion after injection. Dialysis-based release studies showed sustained, composition-dependent release, with cyclic carbonate polymers releasing their cargo faster than the lactone versions. Together, these results show that side-chain chemistry is a powerful design tool for tuning degradation, injectability, and release behavior.
Looking ahead
Overall, this work introduces a versatile platform of hydrolytically and thermally programmable polymers with promise for injectable therapeutics, tissue adhesives, controlled-release systems, and smart biomedical interfaces. Our next steps will focus on optimizing these materials for specific therapeutic cargos, evaluating their biological performance, and exploring additional hydrolyzable monomers as side chains, all aimed at moving this platform closer to practical biomedical use.
Meet the authors
 Maryam Behzad Khoshgoee |
Maryam Behzad Khoshgoee is a PhD candidate in Chemistry at Case Western Reserve University, where her work brings together organic synthesis and polymer chemistry. Her research focuses on monomer synthesis, post-polymerization modification, and the design of hydrolyzable, thermoresponsive polymers for injectable biomedical applications. Her work aims to understand how molecular structure influences polymer properties, with the goal of developing tunable materials for controlled release, tissue engineering, and smart biomedical interfaces. |
 Mithun Kumar Debnath |
Dr Mithun Kumar Debnath is a Postdoctoral Scholar in the Department of Mechanical and Aerospace Engineering at Case Western Reserve University. He received his Ph.D. in Organic and Polymer Chemistry from Toyohashi University of Technology in 2022. His interdisciplinary research merges organic chemistry, polymer chemistry, advanced materials, and fire safety engineering, concentrating on sustainable and biodegradable polymers, controlled radical polymerization, photopolymerization, polymer recycling, thermoset resins, biomaterials, and functional polymer architectures. Currently, his work focuses on thermal runaway of battery, combustion and pyrolysis, fire safety, and the development of flame-retardant and fire-safe materials for next-generation energy and environmental applications. |
 Griffin Pardo |
Griffin Pardo recently graduated from Case Western Reserve University where he studied chemistry and chemical biology. Currently, he will be joining Rutgers as a PhD candidate studying organic chemistry in 2026. During his time at CWRU, he joined the Karayilan research group in the Spring of 2024 as an undergraduate researcher where he explored hydrolyzable thermoresponsive polymers with applications in drug delivery, tissue adhesives, and smart biomedical interfaces. |
 Yichun (Lucia) Yuan |
Yichun (Lucia) Yuan is a fourth-year PhD candidate in Chemistry at Case Western Reserve University, working in the field of polymer chemistry and biomaterials. Her research focuses on automated and semi-batch RAFT polymerization and the development of fluorescent polymers for biomedical applications. Her work aims to create accessible and scalable strategies for advanced polymer synthesis while translating functional polymer materials toward real-world healthcare technologies. |
 Muhammad Zeeshan |
Muhammad Zeeshan was a postdoctoral trainee in the Gurkan group at Case Western Reserve University at the time of this study and he is currently a researcher at Massachusetts Institute of Technology. Zeeshan earned his PhD degree in Chemical Engineering from Koc University, Turkiye. His expertise is the development of sorbents for separations and electrocatalysis. |
 Erqian Mao |
Erqian Mao is a chemistry PhD student at Case Western University working with Dr. Thomas Gray. His research focuses on inorganic chemistry, computational chemistry and photochemistry. |
 Burcu (Eksioglu) Gurkan |
Burcu (Eksioglu) Gurkan is the Kent Hale Smith II Professor of Case School of Engineering at Case Western Reserve University. Her team synthesizes and investigates deep eutectic solvents, ionic liquids, and water-in-salt electrolytes for solving problems in separations, electrocatalysis, energy storage and conversion. Gurkan developed electromagnetic field aided separations for sorbent regeneration and this study showcases the utility of radiofrequency application for transitions in polymers for controlled release applications. |
 Matthew Bertin |
Dr. Matthew Bertin completed his PhD at the Medical University of South Carolina and completed postdoctoral training in the laboratory of William Gerwick at the Scripps Institution of Oceanography. He has been a faculty member at CWRU since 2023. Dr. Bertin’s expertise is in the isolation and structure elucidation of natural products, especially cyanobacterial and algal toxins. |
 Metin Karayilan |
Metin Karayilan is an Assistant Professor of Chemistry at Case Western Reserve University (CWRU). He is a polymer chemist interested in materials development for biomedical and sustainable chemistry applications. His research group at CWRU designs novel polymer architectures, including hyperbranched, bottlebrush, and thermoresponsive materials, for use in tissue engineering, drug delivery, diagnostics, coatings, viscosity modifiers, and fuel additives. Using automation and high-throughput synthesis, the group studies how polymer architecture and composition shape properties such as degradation, flow behavior, and stimuli-responsiveness. |
Multi-responsive polymers with degradable side-chain functionality for controlled hydrolysis and tunable thermal transition
Maryam Behzad Khoshgoee, Mithun Kumar Debnath, Griffin Pardo, Yichun Yuan, Muhammad Zeeshan, Erqian Mao, Thomas G. Gray, Burcu Gurkan, Matthew J. Bertin and Metin Karayilan
RSC Appl. Polym., 2026, 4, 984-1001. DOI: 10.1039/D5LP00379B
This article is part of our RSC Applied Polymers Emerging Investigators 2025 collection – explore the full collection here!
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