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Self-organized structures at polymer gel surfaces: Mechanisms, controlled design, and perspectives

Polymer Journal (2025)Cite this article

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Abstract

Polymer gels are widely utilized in biomedical applications such as drug delivery, tissue engineering scaffolds, and wound dressings, where their surfaces directly interface with living systems. While extensive research has been devoted to solid polymer surfaces with nanoscale control, systematic investigations of gel surfaces have been relatively limited. This review highlights self-organized structures emerging at gel surfaces, including skin layers, shrinkage- and wrinkle-type patterns, and phase-separated structures, which critically influence both interfacial and bulk properties. Historical studies from the 1980s and 1990s revealed diverse structural phenomena, yet uncertainties in their occurrence, often depending on chemical composition and systematic regulation, remain unresolved. Recent advances, particularly surface grafting techniques employing living radical polymerization, have enabled enforced induction and controlled design of such structures at multiple spatial scales. These insights establish a new perspective on the structure–property relationships of gels, emphasizing the interplay between the surface and bulk. Beyond fundamental understanding, this concept has broad implications for the rational design of advanced biomaterials.

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Acknowledgements

This work was supported in part by the SENTAN (JPMJSN16B3) and A-STEP (JPMJTR20T4) programs of the Japan Science and Technology Agency (JST), as well as by JSPS KAKENHI (23H04934 and 25K15908).

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Authors and Affiliations

  1. Department of Human-Centered Engineering, Faculty of Transdisciplinary Engineering, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo, 112-8610, Japan

    Aya M. Akimoto

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  1. Aya M. Akimoto
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Correspondence to Aya M. Akimoto.

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Submitted to the special issue on “Biocompatible Polymers: Fundamentals and Applications” of Polymer Journal

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Akimoto, A.M. Self-organized structures at polymer gel surfaces: Mechanisms, controlled design, and perspectives. Polym J (2025). https://doi.org/10.1038/s41428-025-01123-8

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