Transparent silk hydrogels as a versatile platform for cell culture and imagingDownload PDF Download PDF ArticleOpen accessPublished: 25 July 2026Sarah Stadlmayr ORCID: orcid.org/0000-0002-1461-62741 na1,Tove Kivijärvi1 na1,Bryan Gross2,Tomas Bohn Pessatti ORCID: orcid.org/0000-0003-4497-31572,Benjamin Schmuck ORCID: orcid.org/0000-0003-4021-64582 &…Anna Rising ORCID: orcid.org/0000-0002-1872-12071,2 Communications Materials (2026) Cite this article We are providing an unedited version of this manuscript to give early access to its findings. Before final publication, the manuscript will undergo further editing. Please note there may be errors present which affect the content, and all legal disclaimers apply.SubjectsBioinspired materialsBiomaterialsProteinsAbstractRecombinant spider silk proteins (spidroins) are emerging as a promising feedstock for biomaterial production due to their inherent ability to form hydrogels at 37 °C. However, their broader application as a robust cell culture platform has been hindered by slow gelation kinetics, CO2-induced turbidity, unknown long-term stability, and the use of Tris-HCl buffers that are suboptimal for most mammalian cells. In this study, we aimed to accelerate gelation kinetics of mini-spidroin-based hydrogels, reduce their turbidity, and improve gel stability under physiological conditions. Systematic evaluation of protein pre-treatments and buffer compositions identified parameters governing conformational behavior, gelation dynamics, and structural stability. Multimodal characterization, including turbidity measurements, circular dichroism spectroscopy, Fourier-transform infrared spectroscopy, mechanical assessment, transmission electron microscopy, Thioflavin T assays, and in vitro studies, enabled the formulation of a cytocompatible buffer system optimized for mini-spidroin hydrogels. The formulation improves transparency and accelerates gelation, while maintaining experimental simplicity, thereby advancing the utility of mini-spidroin hydrogels as cell culture platforms.AcknowledgementsThis work was supported through the Swedish Research Council (2024-02919) and Swedish Research Council for Sustainable Development, FORMAS (2023-00871). Moreover, this research was funded in part by the Austrian Science Fund (FWF) [10.55776/J4936]. The authors thank Andreas Barth (Stockholm University) for his input and the scientific discussion regarding ATR-FTIR spectroscopy results. The authors further thank Monika Hodik, from Uppsala University BioVis Electron Microscopy facility, for assisting with sample preparation and TEM imaging. Additionally, we would like to acknowledge Carolin Geiger for assisting with gelation studies and Urmimala Chatterjee, Karolinska Institutet, for providing purified His6-NT protein.FundingOpen access funding provided by Karolinska Institute.Author informationAuthor notesThese authors contributed equally: Sarah Stadlmayr, Tove Kivijärvi.Authors and AffiliationsDepartment of Medicine Huddinge (MedH), Karolinska Institutet, Neo, Stockholm, SwedenSarah Stadlmayr, Tove Kivijärvi & Anna RisingDepartment of Animal Biosciences, Swedish University of Agricultural Sciences, Uppsala, SwedenBryan Gross, Tomas Bohn Pessatti, Benjamin Schmuck & Anna RisingAuthorsSarah StadlmayrView author publicationsSearch author on:PubMed Google ScholarTove KivijärviView author publicationsSearch author on:PubMed Google ScholarBryan GrossView author publicationsSearch author on:PubMed Google ScholarTomas Bohn PessattiView author publicationsSearch author on:PubMed Google ScholarBenjamin SchmuckView author publicationsSearch author on:PubMed Google ScholarAnna RisingView author publicationsSearch author on:PubMed Google ScholarCorresponding authorsCorrespondence to Sarah Stadlmayr or Anna Rising.Ethics declarationsCompeting interestsThe authors declare no competing interests.Additional informationPublisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Supplementary informationTransparent Peer Review file (download PDF )Supplementary Information (download PDF )Rights and permissionsOpen Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Reprints and permissionsAbout this articleDownload PDF