Oliver Drozdowski

Really cool. Sleeping cats are apparently chiral. Now let‘s put them on a lattice and see if they align.

Graduates of the Max Planck Schools holding certificates next to a banner

🥳 We celebrated the first-ever graduation ceremony of the #maxplanckschools at Bildungscampus in Heilbronn– Congratulations to all MPS graduates, and especially to our very own Brianda Santini, Kevin Kaub, Leila Abbaspour, and Oliver Drozdowski!
Read more: www.maxplanckschools.org/551712/gradu...

Great thread, thank you for all the references! We recently posted a preprint on force inference for organoids with an accompanying Python tool, ForceIn3D, which we will hopefully publish soon together with the paper (www.biorxiv.org/content/10.1...).

Excited about the new work from Z. Dunajova & S. Tasciyan (with the Sixt lab @ISTA) - how the mechanical heterogeneity of the environment can be (by itself!) a driver of tumor cell dissemination! www.biorxiv.org/content/10.1... Combination of in vitro exp, simulations and KPZ stat phys!👇🧵1/n

📝 New preprint! 📝

(1/6) Collaborative work between me and @omdrozdowski.bsky.social on 3D force inference for intestinal organoids is now on bioRxiv:

www.biorxiv.org/content/10.1...

From the labs of @ulrichschwarz.bsky.social and @michaelboutros.bsky.social .bsky.social with help from U. Engel.

📢 Preprint alert 📢

(1/6) Our work on 3D force inference for intestinal organoids is now on bioRxiv:

www.biorxiv.org/content/10.1...

Stunning collaboration between @omdrozdowski.bsky.social and @kimboonekamp.bsky.social from the lab of @michaelboutros.bsky.social and with Ulrike Engel. A short🧵...

Fully three-dimensional force inference in intestinal organoids reveals ratchet-like bud stabilization The intestinal epithelium in vertebrates has a characteristic architecture of protruding villi and receding crypts that enables nutrient absorption and cellular turnover. Intestinal organoids recapitu...

This work was my main PhD project @uniheidelberg.bsky.social and @mattertolife.bsky.social. I am proud that we can present it now! If you are interested, please check out our preprint on bioRxiv: biorxiv.org/content/10.1...

So can we find a signature of this effect in our inference? Yes. We introduce line tension inference and find that apical and basal line tensions seem to be increased. Especially the basal line tensions can only be explained through additional intracellular physics.

No! Tensions decrease afterwards and, in fact, apical tension and the apico-basal tension difference in buds decrease. We even find anti-correlation of tissue-scale
mean curvature H and cell-scale tension difference. Thus a ratchet-like mechanism has to maintain bud shape.

We next looked at budding intestinal organoids and found that at the time point where budding occurs (48h) apico-basal tension differences are increased, leading to spontaneous curvature. Buds form through apical contraction. Are they stabilized through this mechanism though?

Our method has been extensively tested on in-silico organoids, which we have simulated with our recently introduced bubbly vertex model. Organoids are modeled through cell interfaces subject to surface and line tensions and inference results are tested against ground truth data.

We developed a 3D reconstruction method, where we perform segmentation of organoid image stacks with subsequent geometrical reconstruction in order to use force balance to infer underlying surface and line tensions.

📝 New preprint! 📝
Happy to share a new preprint from @kimboonekamp.bsky.social and me: We developed a 3D force inference method for budding organoids!
biorxiv.org/content/10.1...
From the labs of @ulrichschwarz.bsky.social and
@michaelboutros.bsky.social with help from U. Engel.
Here the details.

Picture of ISTA logo on a building with blossoming cherry trees in front.

Spring brings new beginnings.. Happy to start my new position @istaresearch.bsky.social as a post doc with @ehannezo.bsky.social. Looking forward to learn new things and study new problems in the realm of multicellular structures. Also: Vienna is beautiful.

📣 Paper alert 📣

Our joint work with the group of Peter Bastian on the positioning of stress fibers in mechanically challenged cells is now out in the Journal of the Mechanics and Physics of Solids

This work was technically very challenging, so it deserves a 🧵 for explanations ...

Starting a theoretical biophysics starter pack, feel free to (self-) nominate, I’ll keep updating this in the next days/weeks!

go.bsky.app/RMF7jUK

Great work by @omdrozdowski.bsky.social who found that the bubbly vertex model naturally leads to cell bulging and extrusion at topological (pentagonal) defects in curved epithelia. Read the preprint at arxiv.org/abs/2411.07141

Morphological instability at topological defects in a three-dimensional vertex model for spherical epithelia The mechanics of spherical epithelial sheets like cysts or intestinal organoids can be described by a three-dimensional vertex model. The vertex model is coarse grained to an elastic continuum theory ...

If this image was intriguing, I invite you to check out the publication: doi.org/10.1103/Phys....
There is actually some nice follow-up work on the arXiv, which I will discuss soon in a Bsky thread.

Buckled vertex model simulation of a rectangular sheet that looks like a butterfly, resembling the Bsky logo.

Time to say goodbye, or rather hello.
A while ago I did a few simulations of plate compression in the 3D vertex model for a publication in Physical Review Research.
This plate, which was compressed a bit too much, nicely resembles the Bsky logo, so let's start the discussion appropriately!