Polymeric thermogels: Fundamentals and strategies for their rational design

Thermogels are promising biomaterials with the ability to attain temperature-induced sol-gel transitions. This property enables their injectability, facilitating minimally invasive administration for a range of biomedical applications including drug delivery, tissue engineering and wound healing. However, their assembly via physical crosslinks often result in weaker mechanical properties when compared to covalent hydrogels. Over the years, the development of more sophisticated thermogels by leveraging past insights and incorporating novel synthetic and fabrication techniques has successfully resulted in a wide variety of thermogels with a range of physicochemical properties. This has enabled the precise control over the physical and chemical characteristics of thermogels, allowing their customization for various applications through rational design. This review categorizes the desirable qualities of thermogels into key physical and biochemical properties, highlighting their importance in performance optimization. Then, it explores the various strategies and approaches that have been used by research groups to precisely tailor thermogel properties, discussing the insights gained from these results. Finally, the review provides a perspective on the future of thermogel development. Collectively, the insights provided herein will guide rational and targeted design of thermogel properties that serve emerging biomedical applications and beyond.