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Zwicker Group

@zwickergroup.bsky.social

Theoretical biophysics group at MPI-DS, Göttingen. We study the spatiotemporal organization of soft matter in cells, tissues, and synthetic systems; see www.zwickergroup.org

1,561 Followers  |  281 Following  |  98 Posts  |  Joined: 12.11.2024
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Posts by Zwicker Group (@zwickergroup.bsky.social)

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Our second Cornell-era preprint is also out!

Kaarthik's paper discusses the gap between cellular and in vitro condensates. In cells, condensates are low-contrast (small partition coefficients), enabling a wide range of responses.

Congrats, Kaarthik and the team!

www.biorxiv.org/content/10.6...

28.02.2026 17:09 — 👍 14    🔁 5    💬 1    📌 1
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The Biophysical World Inside a Jam-Packed Cell | Quanta Magazine Innovations in imaging and genetic engineering are coming together to probe the biophysics of cytoplasm inside living animals.

Density. Crowding. Tomato. Tomato 🍅

@gabepopkin.bsky.social kin.bsky.social @quantamagazine.bsky.social Thx for covering the debate! We promise we're all friends 🥰 @liamholt.bsky.social & @gwgl.bsky.social

Nothing would have been possible without @gucklab.bsky.social @vasilyzaburdaev.bsky.social

23.02.2026 08:41 — 👍 20    🔁 7    💬 1    📌 1
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Less than two weeks left to apply for a Theory Post-doc on Learning in Biological and Soft Matter with us @TU_Munich. Uncover how flows transport and process information to solve complex tasks. #PhDposition #academicjobs www.bpm.ph.tum.de/join-us/

04.02.2026 13:39 — 👍 5    🔁 1    💬 0    📌 0
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The EMBO Young Investigator Network consists of young investigators, installation grantees and global investigators. 🧪

Find more information on the individual programmes here:
https://www.embo.org/the-embo-communities/embo-young-investigator-network/
#LifeSciences #research #funding

02.02.2026 06:55 — 👍 8    🔁 8    💬 0    📌 0
Graphical abstract of pre-print

Graphical abstract of pre-print

Does targeting enzymes and substrates in a condensate lead to rate enhancement? No. Here, we investigate how the condensate environment can inhibit an enzyme reaction.

Spoiler: Mass-transport limitations. We find a strong correlation between diffusion and reaction rates.

doi.org/10.64898/202...

02.02.2026 14:25 — 👍 49    🔁 21    💬 4    📌 2
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Really excited to share our new paper in @nature.com! We uncovered how a physical instability of the cytoplasm coupled with the cell cycle drives cytoplasmic partitioning in early embryos #zebrafish #drosophila. Read more in this🧵 www.nature.com/articles/s41... 🤩
@poldresden.bsky.social @mpi-cbg.de

28.01.2026 16:10 — 👍 176    🔁 53    💬 4    📌 8
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Physics of droplet regulation in biological cells Physics of droplet regulation in biological cells, Zwicker, David, Paulin, Oliver W, ter Burg, Cathelijne

The final version of the review has now been published at Rep. Prog. Phys.: doi.org/10.1088/1361...

We hope the review is helpful, and we'd like to thank everyone who helped us improve the text during the revision phase!

28.01.2026 09:13 — 👍 4    🔁 0    💬 0    📌 1
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You have a background in math/physics/computer science/ML and are looking for an interdisciplinary postdoc fellowship in life sciences with free choice of host groups? Then join us at the CSBD as an ELBE postdoc! The application deadline is the 13 of March

28.01.2026 08:19 — 👍 11    🔁 9    💬 0    📌 1
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Our Mini Review went online last night in Current Opinion in Genetics & Development
"Block copolymer concepts of how transcription organizes the stem cell genome"
doi.org/10.1016/j.gd...

Fig. 1: Stem cell–typical organization of the genome and transcription, and the block copolymer sorting concept.

15.01.2026 08:04 — 👍 23    🔁 10    💬 3    📌 1

Excited to talk to the Matter to Life community about droplets and life!

15.01.2026 07:41 — 👍 11    🔁 2    💬 0    📌 0

How does protein folding change inside biomolecular condensates?

Our new preprint put forwards a framework for predicting this!! 🥳🥳🥳🥳 work by the talented @nathanieldhess.bsky.social

14.01.2026 21:22 — 👍 35    🔁 13    💬 0    📌 0

"While the concept of condensates is successfully rewriting cell biology textbooks, there is some danger of overhype and backlash."

This workshop summary is great - particularly the idea to shift from "Is it a condensate?" to "what problem does that solve?"

but "successfully" stood out for me here

08.01.2026 11:15 — 👍 13    🔁 5    💬 0    📌 0

Curtesy of @jerelleaj.bsky.social who was our amazing master of the black board!

08.01.2026 10:36 — 👍 3    🔁 0    💬 0    📌 0
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Roadmap for Condensates in Cell Biology Biomolecular condensates govern essential cellular processes yet elude description by traditional equilibrium models. This roadmap, distilled from structured discussions at a workshop and reflecting t...

Our "Roadmap for Condensates in Cell Biology" is now available on arXiv: arxiv.org/abs/2601.03677 🎉 This article summarizes the interdisciplinary weekly discussions we had at our condensate workshop at KITP in the summer of 2025. Feedback is very welcome!

08.01.2026 07:33 — 👍 11    🔁 9    💬 2    📌 1

All the best, Aljaz!

30.12.2025 15:02 — 👍 1    🔁 0    💬 0    📌 0
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We're looking for a postdoc to strengthen our group! Please apply by January 15, 2026 if you're a fun and motivated person who likes theoretical modeling of biological processes by combining analytics and numerics. There is freedom in choosing projects! Details: www.ds.mpg.de/4110032/job_...

17.12.2025 12:38 — 👍 7    🔁 6    💬 0    📌 0
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Size control guidelines for chemically active droplets Biological cells and synthetic analogues use liquid-liquid phase separation to dynamically compartmentalize their environment for various applications. In many cases, multiple droplets need to coexist...

Our work helps us to understand the fundamental behaviors of chemically active droplets. We hope that it guides future understanding of biomolecular condensates and also experiments reconstituting these droplets in synthetic systems. Details are available in the pre-print: arxiv.org/abs/2512.02542

15.12.2025 08:07 — 👍 0    🔁 0    💬 0    📌 0

More generally, we identified that reactions can either take place in the entire droplet volume or just in a region limited to the interface. These two different classes of droplets behave qualitatively differently.

15.12.2025 08:07 — 👍 0    🔁 0    💬 1    📌 0
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Our simplest model describes a binary fluid, which exhibits phase separation and conversion of the two species into each other. Using linear non-equilibrium thermodynamics, we asked how different conversion rates affect droplet sizes, and this parameter dependence turned out to be complex.

15.12.2025 08:07 — 👍 0    🔁 0    💬 1    📌 0
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Size control guidelines for chemically active droplets Biological cells and synthetic analogues use liquid-liquid phase separation to dynamically compartmentalize their environment for various applications. In many cases, multiple droplets need to coexist...

Since more than a decade, our group has been exploring chemically active droplets, which are exciting since their size can be controlled. Yet, we still do not fully understand this control even in the simplest models. Until a new preprint (arxiv.org/abs/2512.02542) spearheaded by postdoc Guido...

15.12.2025 08:07 — 👍 12    🔁 3    💬 1    📌 0

Congratulations, Anna! Welcome to this great program 🎉

02.12.2025 17:31 — 👍 1    🔁 0    💬 0    📌 0

Wow, congratulations!

27.11.2025 14:07 — 👍 1    🔁 0    💬 0    📌 0
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📢 Paper alert 📢

Chirality is known to be important for the movement of microorganisms and active matter. In our new paper out today in @natphys.nature.com, we show that chirality is used by malaria parasites to control their motion patterns:

doi.org/10.1038/s415...

Here comes a 🧵 ... (1/9)

24.11.2025 17:50 — 👍 82    🔁 33    💬 1    📌 2
Four simulation snapshots showing various possible configurations in phase separating systems with short-range interactions.

Four simulation snapshots showing various possible configurations in phase separating systems with short-range interactions.

In contrast, short-range interactions (e.g., non-local elasticity and Riccardo's system discussed above) show various patterns, which can be explained by a mapping to the Swift-Hohenberg model. These results demonstrates that various processes arresting droplet coarsening fall into two categories.

24.11.2025 09:45 — 👍 0    🔁 0    💬 0    📌 0
Simulation snapshot showing a patterned phase with many small droplets  in a hexagonal arrangement.

Simulation snapshot showing a patterned phase with many small droplets in a hexagonal arrangement.

Filipe's work (in collaboration with Yicheng and Oliver) puts these results in context by generally studying the influence of non-local interactions onto phase separation. We find that long-range interactions (e.g., electrostatics and also chemical reactions) generally suppress phase separation.

24.11.2025 09:45 — 👍 0    🔁 0    💬 1    📌 0
Simulation snapshot showing a single large droplet coexisting with a patterned phase comprising multiple smaller droplets.

Simulation snapshot showing a single large droplet coexisting with a patterned phase comprising multiple smaller droplets.

Active processes can further control the droplet dynamics. They can either accelerate coarsening, or they can suppress it completely. In the latter case, we also find interesting states where a macroscopic droplet coexists with a patterned phase comprising many smaller spots.

24.11.2025 09:45 — 👍 0    🔁 0    💬 1    📌 0
Top: Schematic of our model describing interacting solutes that phase separate in a 2D surface and exchanges with a 3D bulk. Bottom: Snapshots of numerical simulations with and without passive exchange.

Top: Schematic of our model describing interacting solutes that phase separate in a 2D surface and exchanges with a 3D bulk. Bottom: Snapshots of numerical simulations with and without passive exchange.

Riccardo and Gerrit looked at condensates embedded in membranes, using polarity spots of yeast as an example. They showed that exchange with the bulk can strongly accelerate coarsening, allowing cells to form one spot quickly.

24.11.2025 09:45 — 👍 0    🔁 0    💬 1    📌 0

Two more pre-prints from the group 🎉 Riccardo explored how cells could control surface condensates by regulating bulk exchange (arxiv.org/abs/2511.03619). Filipe studied the impact of non-local interactions onto phase separation (arxiv.org/abs/2511.05214). Some more details in the thread:

24.11.2025 09:45 — 👍 7    🔁 2    💬 1    📌 0

No, I don’t agree with such a blanket statement. Equilibrium concepts can also be useful in non-equilibrium situations. For instance, phase coexistence may hold at the interface, while active processes modulate the bulk phases. I propose a more nuanced view, depending on the concrete system.

21.11.2025 18:41 — 👍 0    🔁 0    💬 0    📌 0

I don’t know the details of this paper, but one generally needs to be cautious. Phase separation can be a useful conceptual framework, but since cells are complex, it can rarely be „proven“.

21.11.2025 18:30 — 👍 0    🔁 0    💬 0    📌 0