Hierarchically Structured and Tunable Hydrogel Patches: Design, Characterization, and Application

Small, vol. 21, pp. e2407311

Abstract

Recent studies show the importance of hydrogel geometry for various applications, such as encoding, micromachines, or tissue engineering. However, fabricating hydrogel structures with micrometer-sized features, advanced geometry, and precise control of porosity remains challenging. This work presents hierarchically structured hydrogels, so-called hydrogel patches, with internally deviating regions on a micron-scale. These regions are defined in a one-step, high-throughput fabrication process via stop-flow lithography. Between the specified projection pattern during fabrication, an interconnecting lower crosslinked and more porous hydrogel network forms, resulting in at least two degrees of crosslinking within the patches. A detailed investigation of patch formation is performed for two material systems and pattern variations, revealing basic principles for reliable patch formation. In addition to the two defined crosslinked regions, further regions are implemented in the patches by adapting the pattern accordingly. The variations in pattern geometry impact the mechanical characteristics of the hydrogel patches, which display pattern-dependent compression behavior due to predefined compression points. Cell culture on patches, as one possible application, reveals that the patch pattern determines the cell area of L929 mouse fibroblasts. These results introduce hierarchically structured hydrogel patches as a promising and versatile platform system with high customizability.

Authors 8

1. Lea Steinbeck Aachen Chemical Process Engineering AVT.CVT

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

2. Richard Paul Aachen Chemical Process Engineering AVT.CVT

   DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

   DWI – Leibniz‐Institute for Interactive Materials e. V. Forckenbeckstraße 50 52074 Aachen Germany

3. Julia Litke Aachen Chemical Process Engineering AVT.CVT

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

4. Isabel Karkoszka Aachen Chemical Process Engineering AVT.CVT

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

5. G. Philip Wiese Aachen Chemical Process Engineering AVT.CVT

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

6. John Linkhorst Aachen Chemical Process Engineering AVT.CVT

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

7. Laura De Laporte Aachen Institute of Technical and Macromolecular Chemistry

   DWI – Leibniz Institute for Interactive Materials · Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Center for Biohybrid Medical Systems (CBMS) Advanced Materials for Biomedicine (AMB) Institute of Applied Medical Engineering (AME) University Hospital RWTH Aachen Forckenbeckstraße 55 52074 Aachen Germany

   DWI – Leibniz‐Institute for Interactive Materials e. V. Forckenbeckstraße 50 52074 Aachen Germany

   Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 1‐2 52074 Aachen Germany

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1-2, 52074 Aachen, Germany

8. Matthias Weßling corresponding Aachen Chemical Process Engineering AVT.CVT

   DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering AVT.CVT RWTH Aachen University Forckenbeckstraße 51 52074 Aachen Germany

   DWI – Leibniz‐Institute for Interactive Materials e. V. Forckenbeckstraße 50 52074 Aachen Germany