![\"Programme](\"https://www.epfl.ch/campus/art-culture/wp-content/uploads/2026/09/LES_CULTURELLES_1920x1080_programme_complet.png\")
\r\n\r\nWeekly BioEngineering Talks (Lunch Provided)
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\r\nINVITED SPEAKER:
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\r\nDe novo design of light-responsive proteins
\r\nDr. Alexander Hilditch, EPFL Laboratory of Protein Design & Immunoengineering
\r\nHost: Prof. Bruno Correia
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\r\nBioEngineering Talks mandatory EDBB Seminar Attendance (1st-Year PhD Students)\r\n
Thesis Director: Prof. D. Constam,
\r\nMolecular Life Sciences doctoral program
\r\nThesis Nr. 11085
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\r\nTo take part in the public defense, please contact directly the speaker
Biological systems have already paved several routes for bioinspired materials, e.g., for structural colours, wetting, adhesion, and mechanical properties. They have largely involved equilibrium or kinetically trapped properties. By contrast, biological systems allowing multifunctional properties are characteristically dissipatively and dynamically adaptive and incorporate homeostatic feedback mechanisms to regulate the dynamic states. They also typically use signal transduction to mediate the signal from the sensory elements to the responsive sites, unlike the classic man-made stimuli responsive materials. These concept suggest avenues towards more complex life-like functions in soft matter. Herein, optically driven hydrogel systems are presented to drive homeostatically controlled thermal oscillations and to mediate signal transduction via thermal intermediate signalling (1). On the other hand, biological magnetoreception in elasmobranch organisms involves electromagnetic induction (EMI) and suggests avenues for bioinspired electrical signal transductions. We show magnetic profile recognition of translocated magnetically encoded soft matter objects using electrical intermediate signaling by EMI and decoding the magnetic information with machine learning (2). Combination of high stiffness and promoted dynamics for self-healing has turned challenging to combine. Self-healing hydrogels, still combining high tensile stiffness close to that of skin were shown by using polymers upon nanoconfinement in 2D-nanosheet layered confinements (3). Finally, we show trainable actuations in bilayer gel actuators (4). Ever more complex responses can be created, such as mimicking the Pavlovian classical conditioning (5), all paving ways for growingly life-like functions for soft robotics and interfacing with biology.
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\r\n1. H. Zhang, H. Zeng, A. Eklund, H. Guo, A. Priimagi, O. Ikkala, Feedback-controlled hydrogels with homeostatic oscillations and dissipative signal transduction, Nat. Nano, 17, 1303 (2022).
\r\n2. Z. Miao, X. Hu, K. Liu, S. Hu, G. Yan, H. Tan, O. Ikkala, Z. P. Lv, B. Peng, Bioinspired sensory transduction for magnetic profile recognition and encryption, Adv. Mat. 38 e15994 (2026).
\r\n3. C. Liang, V. Dudko, O. Khoruzhenko, X. Hong, Z.-P. Lv, J. Breu, O. Ikkala, H. Zhang, Stiff and self-healing hydrogels by polymer entanglements in co-planar nanoconfinement, Nat. Mater. 24, 599 (2025).
\r\n4. S. Hu, Y. Fang, C. Liang, M. Turunen, O. Ikkala, H. Zhang, Thermally trainable dual network hydrogels, Nat. Commun., 14, 3717 (2023).
\r\n5. H. Zhang, H. Zeng, A. Priimagi, O. Ikkala, Programmable responsive hydrogels with classical conditioning algorithm, Nat. Commun., 10, 3267 (2019).
Thesis Director: Prof. L. Zdeborová,
\r\nComputer and Communication Sciences doctoral program
\r\nThesis Nr. 11792
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\r\nTo take part in the public defense, please contact directly the speaker
Le projet Unearthed de l’artiste Rahel Oberhummer est une aventure visuelle et scientifique au cœur du développement de micro-organismes contenus dans le pergélisol de la montagne Muot da Barba Peider (Schafberg) en Engadine et collectés par l'Institut fédéral de recherches sur la forêt, la neige et le paysage (WSL). Cette collection préserve des micro-organismes provenant de régions menacées telles que les Alpes et l'Arctique et compte déjà plus de 2000 spécimens.
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\r\nL’artiste a sélectionné des levures, bactéries et champignons souvent vieux de 12’000 ans, qu’elle a cultivés dans son propre studio et photographiés tous les deux jours. Les différents micro-organismes sont déposés sur un fond d’agar pour qu’ils puissent se développer. Leur évolution est rapide et hasardeuse. La documentation est méthodique : plus de 13'300 photographies ont été prises représentant des instantanés de matière vivante.
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\r\nDeux séries de photographies ont été produites : l’une se concentre sur des monocultures, dans lesquelles une souche microbienne sélectionnée occupe une boîte de Pétri et se propage largement. En adaptant les méthodes d'inoculation et les milieux de culture, différentes impulsions sont déclenchées. La deuxième série fait cohabiter plusieurs organismes différents. La lutte pour les nutriments dans le milieu de culture ainsi que les symbioses qui peuvent se développer entre les microbes sont documentées. La pratique d’atelier se mêle à la pratique de laboratoire.
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\r\nL’exposition
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\r\nL’exposition Unearthed présente 18 photographies de plusieurs micro-organismes différents évoluant dans les boîtes circulaires qui les abritent. Filaments, textures, entrelacs, pointillés, cercles produisent des configurations abstraites spectaculaires. Les couleurs enchantent et vivifient les formes en turbulente circulation et en constante métamorphose. Les photographies pointent le sublime de l’extraordinaire variété des cellules : la naissance du vivant.
\r\nLes photographies de Rahel Oberhummer révèlent deux nécessités indissociables : d’une part celle de comprendre le vivant même dans ses organismes les plus simples et d’autre part de le préserver. Parallèlement, il s’agit de créer des images qui manifestent la qualité visuelle des formes et des couleurs de ces micro-organismes. Notre rapport à la nature exige l’admiration de sa beauté. Aujourd’hui, des artistes comme Rahel Oberhummer s’engagent dans une double mission : participer activement à des processus scientifiques et créer des images sensibles tout autant que savantes.
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\r\nCollaborations
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\r\nSérie photographique réalisée en collaboration avec l’Institut fédéral de recherches sur la forêt, la neige et le paysage (WSL). Unité : Biodiversité et écologie de la conservation.
\r\nDr. Beat Frey, Dr. Joel Rüthi, Dr. Ivano Brunner, Beat Stierli
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\r\nEléments biographiques
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\r\nRahel Oberhummer (*1991, Loèche-les-Bains) est diplômée de la HEAD, Genève. Elle a étudié aussi à la Royal Danish Academy of Fine Arts, Copenhague, à la Hochschule für Kunst und Design de Lucerne et au Billy Blue College of Design à Sydney. Au début de l’année 2026, elle a obtenu une résidence de trois mois à Hanoï, au Vietnam, dans le cadre d’un séjour de recherche soutenu par Pro Helvetia et accueilli par l’espace Exutoire. Elle vit et travaille à Vevey.
\r\nLa relation entre les structures sociales humaines et les formes de vie non humaines est au cœur de son approche artistique. Rahel Oberhummer se concentre sur les interactions subtiles entre les humains et l'environnement, avec une attention soutenue pour les écosystèmes dont nous dépendons et que nous mettons pourtant en danger. Des questions se posent, que l'artiste explore à travers une recherche scientifique autant qu’artistique.
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\r\n>>> Site web de l'artiste Rahel Oberhummer
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\r\nVernissage le jeudi 7 mai 2026 à 18 :30
\r\nExposition visible jusqu’au 11 octobre 2026
\r\nHall du RLC / entrée libre
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\r\nImage : Dioszegia patagonica 001, Pochonia/Metacordyceps chlamydosporia 205, Pseudogymnoascus pannorum 511, Potato Dextrose Agar with sepia ink, 2022.
Thanks to a donation from the Claude Latour Foundation, the Pôle Culture (VPI) is organizing a master class followed by a public concert based on the Verbier Festival archives, which are being digitized at EPFL by the EPFL Cultural Heritage & Conservation Platform (CHC).
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\r\nDuring the masterclass, the selected students are invited to create a musical piece lasting no more than 5 minutes in the style, aesthetic, and genre of their choice (jazz, rap, rock, metal, classical, etc.). At the end of the day, the pieces will be presented to the public, accompanied by comments from a panel of experts.
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\r\nPROGRAM:\r\n
\r\n\r\nYou can apply to participate and find all the relevant information (speakers, abstracts, program,...) on the event website: https://www.cecam.org/workshop-details/g-protein-coupled-receptors-functional-dynamics-revealed-by-experimental-and-computational-structural-data-1488.
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\r\nRegistration is required to attend the full event, take part in the social activities and present a poster at the poster session (if any). However, the EPFL community is welcome to attend specific lectures without registration if the topic is of interest to their research. Do not hesitate to contact the CECAM Event Manager if you have any question.
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\r\nDescription
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\r\nG protein-coupled receptors (GPCRs) represent a vast and diverse class of transmembrane proteins that orchestrate a wide range of physiological processes by responding to both endogenous and exogenous ligands [1,2]. These receptors are essential to critical functions such as metabolism, immune regulation, neuronal signaling, and sensory perception - including vision and olfaction. Due to their physiological relevance and membrane accessibility, GPCRs are the targets of approximately 34% of all prescribed medications, accounting for nearly 27% of the global pharmaceutical market [3].
\r\nDespite their pharmaceutical importance, key aspects of GPCR function remain elusive. The canonical activation model posits that agonist binding to the extracellular orthosteric site triggers allosteric changes - most notably, the outward displacement of transmembrane helices 5 (TM5) and 6 (TM6) on the intracellular side - ultimately leading to receptor activation [2-4]. However, recent evidence suggests a more nuanced mechanism. In several GPCRs, activation appears to involve cooperative engagement between the agonist and the G protein. For example, the G protein may disrupt an \"inactivating ionic lock\" - a salt bridge between TM3 and TM6 - while the agonist stabilizes the active conformation. In some receptors, this is complemented by the formation of an “activating ionic lock” between TM5 and TM6 [5-8]. These dual contributions are considered thermodynamically essential for full activation [7].
\r\nAdding further complexity, GPCR activity is regulated by conformational microswitches and finely tuned intra-protein interaction networks. These dynamic rearrangements are difficult to capture and often elude direct correlation with functional outcomes. Moreover, allosteric ligands - which bind sites distinct from the orthosteric pocket - are being increasingly identified [9-12], along with small molecules capable of biased signaling, i.e., preferential activation of specific intracellular pathways [11-13, 16, 17]. These findings reveal a rich and underexplored conformational landscape that governs GPCR signaling. In addition, native membrane components—such as lipids and interacting proteins, including GPCR oligomers—are known to significantly modulate receptor function [11, 18-22].
\r\nTo disentangle these intricacies, computational modeling has become indispensable, offering atomistic insight into GPCR conformational dynamics and mechanistic understanding [1-2, 7, 11, 14, 16–21, 23]. Nevertheless, key questions remain - particularly regarding the structural basis of biased signaling, strategies for leveraging allosteric networks in pharmacology, and the modulatory role of the lipid environment. Addressing these gaps is crucial for both fundamental biology and the rational design of next-generation GPCR-targeting drugs with improved selectivity and safety profiles.
\r\nThese scientific challenges form the foundation of our upcoming workshop, which will focus on the latest experimental and computational approaches for studying the functional dynamics of GPCRs. Given the profound health, economic, and societal implications of modulating these receptors with precision, we aim to strengthen the interdisciplinary nature of the event by increasing the representation of experimental research and integrating cutting-edge artificial intelligence applications into the program.
\r\nBuilding upon the success of the 2022 and 2024 editions - which led to new collaborations and a landmark publication in Nature Reviews Drug Discovery [24] - our goal is to further enhance communication and collaboration between experimentalists and theoreticians. The workshop will serve as a reference point for young scientists and students, offering a platform to interact with leading international experts. We are confident that this initiative will foster insightful discussions and contribute meaningfully to advancing the field of GPCR pharmacology.
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\r\nReferences
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\r\n[1] J. Smith, R. Lefkowitz, S. Rajagopal, Nat. Rev. Drug. Discov., 17, 243-260 (2018)
\r\n[2] P. Conflitti, E. Lyman, M. Sansom, P. Hildebrand, H. Gutiérrez-de-Terán, P. Carloni, T. Ansell, S. Yuan, P. Barth, A. Robinson, C. Tate, D. Gloriam, S. Grzesiek, M. Eddy, S. Prosser, V. Limongelli, Nat. Rev. Drug. Discov., 24, 251-275 (2025)
\r\n[3] L. Picard, A. Orazietti, D. Tran, A. Tucs, S. Hagimoto, Z. Qi, S. Huang, K. Tsuda, A. Kitao, A. Sljoka, R. Prosser, Nat. Chem. Biol., 21, 71-79 (2024)
\r\n[4] B. Huang, C. St. Onge, H. Ma, Y. Zhang, Drug Discovery Today, 26, 189-199 (2021)
\r\n[5] D. Di Marino, P. Conflitti, S. Motta, V. Limongelli, Nat. Commun., 14, 6439 (2023)
\r\n[6] G. Milligan, R. Ward, S. Marsango, Current Opinion in Cell Biology, 57, 40-47 (2019)
\r\n[7] S. Huang, O. Almurad, R. Pejana, Z. Morrison, A. Pandey, L. Picard, M. Nitz, A. Sljoka, R. Prosser, eLife, 11, (2022)
\r\n[8] A. Duncan, W. Song, M. Sansom, Annu. Rev. Pharmacol. Toxicol., 60, 31-50 (2020)
\r\n[9] A. Morales-Pastor, T. Miljuš, M. Dieguez-Eceolaza, T. Stępniewski, V. Ledesma-Martin, F. Heydenreich, T. Flock, B. Plouffe, C. Le Gouill, J. Duchaine, D. Sykes, C. Nicholson, E. Koers, W. Guba, A. Rufer, U. Grether, M. Bouvier, D. Veprintsev, J. Selent, Nat. Commun., 16, 5265 (2025)
\r\n[10] A. Faouzi, H. Wang, S. Zaidi, J. DiBerto, T. Che, Q. Qu, M. Robertson, M. Madasu, A. El Daibani, B. Varga, T. Zhang, C. Ruiz, S. Liu, J. Xu, K. Appourchaux, S. Slocum, S. Eans, M. Cameron, R. Al-Hasani, Y. Pan, B. Roth, J. McLaughlin, G. Skiniotis, V. Katritch, B. Kobilka, S. Majumdar, Nature, 613, 767-774 (2022)
\r\n[11] M. Wall, E. Hill, R. Huckstepp, K. Barkan, G. Deganutti, M. Leuenberger, B. Preti, I. Winfield, S. Carvalho, A. Suchankova, H. Wei, D. Safitri, X. Huang, W. Imlach, C. La Mache, E. Dean, C. Hume, S. Hayward, J. Oliver, F. Zhao, D. Spanswick, C. Reynolds, M. Lochner, G. Ladds, B. Frenguelli, Nat. Commun., 13, 4150 (2022)
\r\n[12] D. Wootten, A. Christopoulos, M. Marti-Solano, M. Babu, P. Sexton, Nat. Rev. Mol. Cell. Biol., 19, 638-653 (2018)
\r\n[13] D. Hilger, M. Masureel, B. Kobilka, Nat. Struct. Mol. Biol., 25, 4-12 (2018)
\r\n[14] D. Aranda-García, T. Stepniewski, M. Torrens-Fontanals, A. García-Recio, M. Lopez-Balastegui, B. Medel-Lacruz, A. Morales-Pastor, A. Peralta-García, M. Dieguez-Eceolaza, D. Sotillo-Nuñez, T. Ding, M. Drabek, C. Jacquemard, J. Jakowiecki, W. Jespers, M. Jiménez-Rosés, V. Jun-Yu-Lim, A. Nicoli, U. Orzel, A. Shahraki, J. Tiemann, V. Ledesma-Martin, F. Nerín-Fonz, S. Suárez-Dou, O. Canal, G. Pándy-Szekeres, J. Mao, D. Gloriam, E. Kellenberger, D. Latek, R. Guixà-González, H. Gutiérrez-de-Terán, I. Tikhonova, P. Hildebrand, M. Filizola, M. Babu, A. Di Pizio, S. Filipek, P. Kolb, A. Cordomi, T. Giorgino, M. Marti-Solano, J. Selent, Nat. Commun., 16, 2020 (2025)
\r\n[15] D. Thal, A. Glukhova, P. Sexton, A. Christopoulos, Nature, 559, 45-53 (2018)
\r\n[16] L. Slosky, M. Caron, L. Barak, Trends in Pharmacological Sciences, 42, 283-299 (2021)
\r\n[17] C. Zhu, X. Lan, Z. Wei, J. Yu, J. Zhang, Acta Pharmaceutica Sinica B, 14, 67-86 (2024)
\r\n[18] V. D’Amore, P. Conflitti, L. Marinelli, V. Limongelli, Chem, 10, 3678-3698 (2024)
\r\n[19] A. Mafi, S. Kim, W. Goddard, Nat. Chem., 15, 1127-1137 (2023)
\r\n[20] H. Batebi, G. Pérez-Hernández, S. Rahman, B. Lan, A. Kamprad, M. Shi, D. Speck, J. Tiemann, R. Guixà-González, F. Reinhardt, P. Stadler, M. Papasergi-Scott, G. Skiniotis, P. Scheerer, B. Kobilka, J. Mathiesen, X. Liu, P. Hildebrand, Nat. Struct. Mol. Biol., 31, 1692-1701 (2024)
\r\n[21] A. Manglik, T. Kim, M. Masureel, C. Altenbach, Z. Yang, D. Hilger, M. Lerch, T. Kobilka, F. Thian, W. Hubbell, R. Prosser, B. Kobilka, Cell, 161, 1101-1111 (2015)
\r\n[22] M. Congreve, C. de Graaf, N. Swain, C. Tate, Cell, 181, 81-91 (2020)
\r\n[23] J. Lorente, A. Sokolov, G. Ferguson, H. Schiöth, A. Hauser, D. Gloriam, Nat. Rev. Drug. Discov., 24, 458-479 (2025)
\r\n[24] M. Lopez‐Balastegui, T. Stepniewski, M. Kogut‐Günthel, A. Di Pizio, M. Rosenkilde, J. Mao, J. Selent, British. J. Pharmacology., 182, 3211-3224 (2024)\r\n
This paper studies optimal financial flexibility in debt issuance. A borrower raises funds for an initial investment and may need financing after observing a private liquidity shock. Under non exclusive lending, new lenders price only their claims, so additional borrowing dilutes existing debt and leads to excessive leverage. The optimal simple debt contract is an endogenous debt limit. It captures the intertemporal commitment–flexibility tradeoff: more borrowing today fi nances investment but increases dilution incentives, requiring tighter limits on future borrowing. Richer clauses, including performance-sensitive debt and contingent prepayment provisions, re store the exclusive-lending benchmark by compensating existing lenders when new financing is raised.
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