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Farid Alisafaei

@faridalisafaei.bsky.social
18 followers 13 following 26 posts

Assistant Professor of Mechanical Engineering @njit.bsky.social ———————————————————— PI, MechanoBiology and BioMechanics (MBBM) Lab www.mbbm-lab.com ———————————————————— Former NIH Postdoc @upenn.bsky.social

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Farid Alisafaei @faridalisafaei.bsky.social · 09/05/2025
Grateful to see our recent work on the mechanics of fibroblast activation featured by NJIT. news.njit.edu/unveiling-bi...
news.njit.edu
Unveiling the Biomechanical Forces that Drive Scarring
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
1️⃣ 1️⃣ Without Microtubules, Direction Does Not Matter! With disruption of microtubules, our theoretical model showed that fibroblasts behaved just as classical models predicted—responding only to stress magnitude, not direction!
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
🔟 Classical Cell Models Fall Short However, classical theoretical models failed: Classical models = stress magnitude matters most Our model = stress anisotropy is the real driver!
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
9️⃣ Model Prediction: Our theoretical model predicted and explained fibroblast activation under tension: When stress was isotropic, fibroblasts stayed inactive. When stress was anisotropic, activation skyrocketed!
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
8️⃣ Microtubules: The Missing Piece in Tension Sensing? When we disrupted microtubules, fibroblasts responded in the opposite way—they activated more under isotropic tension instead of anisotropic tension! This means microtubules are crucial for cells to sense and respond to tension anisotropy
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
7️⃣ Fibroblasts in the Skin: A Natural Example Why is this exciting? Because in tissues like skin, fibroblasts experience anisotropic tension due to collagen alignment along Langer’s lines. By modulating tension direction, we may be able to control fibroblast activation!
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
6️⃣ Tension Anisotropy vs. ECM Stiffness: Which has a bigger impact on fibroblast activation? We found that tension anisotropy is more important than ECM stiffness! On soft matrices, anisotropic tension activated fibroblasts more than stiff isotropic environments.
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
5️⃣ Breaking the Loop Stops Activation: Disrupting this feedback loop—by reducing tension anisotropy or inhibiting protrusions—stopped fibroblasts from activating. This suggests that fibrosis and wound healing could be controlled by tuning stress anisotropy!
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
4️⃣ The Self-Reinforcing Loop: We saw that fibroblasts extend protrusions that interact with collagen fibers. This sets up a self-reinforcing loop: 💠 Protrusions align collagen fibers 💠 Aligned fibers stabilize and strengthen protrusions 💠 This amplifies tension in one direction
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
3️⃣ Why Does This Matter? This transformation is essential for wound healing—but if it goes unchecked, it can lead to excessive scarring and fibrocontractile diseases like fibrosis. Fibrosis not only impairs tissue function but can also promote skin cancer invasion.
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
2️⃣ Tension Anisotropy: A New Activation Factor We found that when fibroblasts experience higher tension in one direction, they activate into highly contractile myofibroblasts.
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Farid Alisafaei @faridalisafaei.bsky.social · 25/03/2025
1️⃣ For years, scientists have known that mechanical tension influences cell behavior. But in our recent study in Nature Materials @naturematerials.bsky.social we found that it is not just the amount of tension—it is the direction! www.nature.com/articles/s41...
nature.com
Tension anisotropy drives fibroblast phenotypic transition by self-reinforcing cell–extracellular matrix mechanical feedback - Nature Materials
Extracellular anisotropic stresses trigger fibroblast transition into myofibroblasts by the mechanical self-reinforcement of cell–extracellular matrix interactions.
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Reposted by Farid Alisafaei
Nate Huebsch @natehuebsch.bsky.social · 25/03/2025
Excited to share our latest work through our collaboration with Guy Genin, led by @faridalisafaei.bsky.social ! source.washu.edu/2025/03/the-...
source.washu.edu
The right moves to rein in fibrosis
Biomedical researchers at Washington University in St. Louis have decoded how mechanical forces drive cell behavior in fibrosis.
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Farid Alisafaei @faridalisafaei.bsky.social · 22/03/2025
6️⃣ Thanks for reading! We'd love to chat about this work. @njit.bsky.social @washu.bsky.social
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Farid Alisafaei @faridalisafaei.bsky.social · 22/03/2025
5️⃣ The opportunity: By controlling mechanical conditions, we can optimize fibroblast memory, leading to better graft integration, less scarring, and improved wound healing.
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Farid Alisafaei @faridalisafaei.bsky.social · 22/03/2025
4️⃣ Why does this matter? In skin grafting for burns and chronic wounds, skin grafts are mechanically stretched before transplantation. How they are stretched determines whether they heal properly or lead to scarring and graft failure.
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Farid Alisafaei @faridalisafaei.bsky.social · 22/03/2025
3️⃣ Our discovery: Fibroblasts in 3D tissues subjected to static mechanical stretching for extended periods retain a memory of the stretch—remaining activated long after the strain is gone.
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Farid Alisafaei @faridalisafaei.bsky.social · 22/03/2025
2️⃣ What we know: Fibroblasts adjust their behavior in response to mechanical forces. But what happens when those forces are removed?
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Farid Alisafaei @faridalisafaei.bsky.social · 22/03/2025
1️⃣ For a long time, we have known that mechanical stretching influences how cells behave. But in our new PNAS paper @pnas.org, we show that fibroblasts do not just respond to stretch—they remember it. www.pnas.org/doi/abs/10.1...
pnas.org
Cell–matrix feedback controls stretch-induced cellular memory and fibroblast activation | PNAS
Mechanical stretch can activate long-lived changes in fibroblasts, increasing their contractility and initiating phenotypic transformations. This a...
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Reposted by Farid Alisafaei
bioRxivpreprint @biorxivpreprint.bsky.social · 07/03/2025
Tension-Induced Stiffening of Cytoskeletal Components Regulates Cardiomyocyte Contractility www.biorxiv.org/content/10.1101/202…
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(8)📖Curious to learn more? Read our full paper in Acta Biomaterialia for free access until Jan 18, 2025: 🔗 authors.elsevier.com/a/1kB0g6CFjZ...
authors.elsevier.com
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(7)🔍A key prediction: Our model predicts that surgeons stop expanding the graft when the two limits diverge. ✅ We compared these predictions with extensive experimental data from surgeries and validated their accuracy across different meshing ratios and donor skin sizes.
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(6)🚀Our solution: We developed a model that uncovers the mechanisms behind skin graft expansion. It captures two key factors involved in skin graft expansion: 1️⃣ Rotation of incision arms 2️⃣ Stretching of the skin The model provides upper and lower limits for graft expansion.
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(5) This overestimation persists across experience levels. Survey data shows no significant difference between estimates from senior surgeons and residents. A better model is essential to improve accuracy and outcomes. pmc.ncbi.nlm.nih.gov/articles/PMC...
pmc.ncbi.nlm.nih.gov
The real expansion rate of meshers and micrografts: things we should keep in mind
Skin graft expansion techniques (mesh and micrograft) are widely used, but there is ample evidence that skin graft meshers do not provide their claimed expansion rates. Although this finding might not...
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(4) Surgeons widely recognize that actual skin graft expansions often fall short of predictions made by the conventional model. Despite this, they overestimate these ratios by 55%, showing a clear need for a more accurate and practical predictive model. pmc.ncbi.nlm.nih.gov/articles/PMC...
pmc.ncbi.nlm.nih.gov
The real expansion rate of meshers and micrografts: things we should keep in mind
Skin graft expansion techniques (mesh and micrograft) are widely used, but there is ample evidence that skin graft meshers do not provide their claimed expansion rates. Although this finding might not...
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(3) Why is predicting graft expansion important? Accurate predictions help surgeons minimize the skin-harvested area, reducing additional trauma. Yet, the conventional model often fails to predict graft expansion accurately in real surgeries.
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(2) To treat chronic wounds, surgeons often use split-thickness skin grafts. A thin skin layer is harvested, meshed with slits, expanded, and transplanted onto a larger wound area.
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Farid Alisafaei @faridalisafaei.bsky.social · 03/12/2024
(1) How can we better predict how much a meshed skin graft expands? What if surgeons had a practical tool to minimize the harvested skin needed for wound coverage? Our new work in Acta Biomaterialia tackles this challenge: sciencedirect.com/science/arti...
sciencedirect.com
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