bims-ecemfi 2025-10-12 papers

Biomaterials. 2025 Oct 04. pii: S0142-9612(25)00682-9. [Epub ahead of print]327 123763

Mineralized bone matrix attenuates breast cancer cell malignancy by altering MSC mechanoregulation.

Nicole Sempertegui, Yiwei Yan, Matthew A Whitman, Garrett F Beeghly, Siyoung Choi, Andrew Miller, Lara A Estroff, Claudia Fischbach.

Bone metastasis, the leading cause of death in breast cancer patients with metastatic disease, initiates by early dissemination of cancer cells to osteogenic niches containing mineralizing collagen matrix and mesenchymal stem cells (MSCs). How collagen mineralization affects MSC phenotype and what consequences these changes have on cancer cells remains unclear. Understanding these links is critical as MSCs regulate cancer cell growth and because decreased bone mineral density increases the risk for bone metastasis. Using biofunctional bone matrix models, we find that mineralization prevents MSC-mediated collagen remodeling by limiting actomyosin contractility while promoting osteogenic differentiation. In the absence of mineral, MSCs develop a profibrotic phenotype that supports breast cancer cell malignancy in vitro and in vivo. These findings highlight that collagen mineralization stimulates MSC osteogenic differentiation by inhibiting profibrotic matrix remodeling rather than by inducing stiffness-dependent mechanosignaling. Collagen mineralization may, therefore, play a key role in regulating whether osteogenic niches provide a favorable or restrictive environment for early stages of metastasis.

Keywords: Biomineralization; Bone metastasis; Mechanosignaling; Mesenchymal stem cells

DOI: https://doi.org/10.1016/j.biomaterials.2025.123763

Biophys J. 2025 Oct 07. pii: S0006-3495(25)00654-X. [Epub ahead of print]

Biphasic curvature-dependence of cell migration: persistent randomness versus directionality.

Xiaoyu Yu, Haiqin Wang, Mingxi Xie, Fangfu Ye, Zhiqi Shen, Xiaochen Wang, Qihui Fan, Xinpeng Xu.

Cell-scale curvature is a key regulator of cell migration, yet its quantitative effects and underlying mechanisms remain elusive. Here, we combine controlled in vitro experiments with a phenomenological theoretical framework to investigate the migration of fibroblasts (NIH3T3) and epithelial cells (MCF10A) on the inner concave surfaces of polydimethylsiloxane (PDMS) microcylinders across a wide range of cell-scale curvatures (∼0.01 per micron). We find that migration persistence positively correlates with mean speed across all curvatures, consistent with the universal speed-persistence coupling relation (UCSP) previously observed for cells migrating on 1D and 2D planar substrates, as well as for cells embedded in 3D environments. Cell migration inside microcylinders is stochastic and anisotropic, as quantified by the nematic order parameter, and exhibits a biphasic dependence on curvature. At small curvatures, cells remain fully adhered to the surface, with anisotropy and speed both increasing while persistence decreases. When curvature exceeds a threshold of approximately 1/75 per micron, cells detach by forming stress fiber chords, leading to reduced anisotropy and speed but increased persistence. This adhered-to-chord (ACT) transition is followed by a shift in preferred orientation: migration initially favors the lateral direction and progressively aligns toward the axis at larger curvatures. These findings demonstrate that cells can actively reorient their stress fibers and migration in response to local cell-scale curvature sensed by the entire cell, even on cylindrical surfaces with constant mean curvature and vanishing Gaussian curvature. A modified persistent random walk model, incorporating persistent randomness and curvature-dependent directionality via bending and adhesion energetics, quantitatively captures these behaviors and predicts the transition threshold in close agreement with experiments. Together, this work establishes a quantitative framework for biphasic, curvature-dependent migration and provides new insight into how local geometry regulates mesenchymal motility.

DOI: https://doi.org/10.1016/j.bpj.2025.10.003

Acta Biomater. 2025 Oct 08. pii: S1742-7061(25)00741-X. [Epub ahead of print]

Rapid Restoration of Cell Phenotype and Matrix Forming Capacity Following Transient Nuclear Softening.

Ryan C Locke, Liane M Miller, Elisabeth A Lemmon, Sereen S Assi, Dakota L Jones, Edward D Bonnevie, Jason A Burdick, Su Jin Heo, Robert L Mauck.

The dense extracellular matrix of connective tissues impedes cell migration and subsequent matrix formation at sites of injury. We recently employed transient histone deacetylase inhibition with trichostatin A (TSA) treatment to increase nuclear deformability (decrease nuclear stiffness) to overcome the stiff nuclear impediments to cell migration through dense tissues and electrospun matrices. Despite these positive findings, the long-term implications of transient nuclear softening on cell transcriptional phenotype and matrix formation capacity are unknown. To address this, we investigated the influence of transient TSA treatment on porcine meniscal cell behavior, beginning with the efficacy and reproducibility of transient TSA treatment on histone acetylation and chromatin remodeling in vitro and cell migration through native meniscus tissue. Within 3 days after cessation of transient TSA treatment, histone acetylation and chromatin remodeling returned to control levels. Following TSA treatment, endogenous cell migration through native meniscus tissue increased greater than 3-fold compared to controls. Importantly, meniscal cells restored their transcriptional phenotype and maintained their capacity to respond transcriptionally and functionally to a secondary pro-matrix stimuli (i.e., transforming growth factor β3) within 7 days after cessation of TSA treatment. We also showed the feasibility of biomaterial-delivered TSA to increase endogenous meniscus cell migration to a wound edge ex vivo. Together, this work defines the feasibility and supports the safety and efficacy of future translational approaches for nuclear softening to treat dense connective tissue injuries. STATEMENT OF SIGNIFICANCE: The dense extracellular matrix of connective tissues impedes cell migration and subsequent matrix formation at sites of injury. We recently employed transient nuclear softening via histone deacetylase inhibition with trichostatin A (TSA) treatment to overcome the stiff nuclear impediments to cell migration through dense tissues and electrospun matrices. Following TSA treatment, endogenous cell migration through native meniscus tissue increased greater than 3-fold compared to controls. Importantly, meniscal cells completely restored their transcriptional phenotype and maintained their capacity to respond transcriptionally and functionally to a secondary pro-matrix stimuli (i.e., transforming growth factor β3) within 7 days after cessation of TSA treatment. Together, this work defines the efficacy, reproducibility, safety, and feasibility of future translational approaches for nuclear softening to treat dense connective tissue injuries.

Keywords: dense connective tissue healing; migration; nuclear stiffness

DOI: https://doi.org/10.1016/j.actbio.2025.10.007

Nat Protoc. 2025 Oct 09.

Manufacturing synthetic viscoelastic antigen-presenting cells for immunotherapy.

Zeyang Liu, Yan-Ruide Li, Youcheng Yang, Enbo Zhu, Haochen Nan, Yue Yan, Bo Zhang, Guorui Chen, Nicolas Pedroncelli, Zibai Lyu, Jason Lin, Jennifer Soto, Lili Yang, Song Li.

This protocol details the preparation and functionalization of viscoelastic synthetic antigen-presenting cells (APCs) for T cell activation, designed to enhance immunotherapeutic efficacy. Using a high-throughput microfluidic system and post-processing, we create cell-sized sodium alginate microbeads with tunable stiffness, viscoelasticity and surface chemistry, enabling them to better mimic the physical and activation properties of natural APCs. The protocol includes fabrication of synthetic cells with defined sizes, crosslinking strategies to achieve desirable mechanical properties, surface functionalization via click chemistry for attaching activation molecules, and characterization methods for mechanical and biochemical properties. Compared with traditional matrices or rigid microbeads, this approach allows precise control over the mechanical and biochemical features of synthetic APCs, ensuring optimal T cell activation. The resulting synthetic cells support robust T cell activation and expansion, enhance the CD8/CD4 T cell ratio, promote T memory stem cell (TMSC) formation and improve chimeric antigen receptor transduction efficiency, leading to superior tumor-killing efficacy in vitro and in vivo. Additionally, these synthetic cells can be efficiently removed from T cells after activation using simple centrifugation or calcium chelation, preserving the activated T cells. The complete protocol, including fabrication, functionalization and quality assessment, requires ~1 week to complete. Users should have experience in microfluidics, biomaterial handling, bioconjugation techniques and basic cell culture. This platform can be adapted for broader applications in immune cell engineering.

DOI: https://doi.org/10.1038/s41596-025-01265-2

J Colloid Interface Sci. 2025 Sep 29. pii: S0021-9797(25)02531-7. [Epub ahead of print]703(Pt 1): 139139

Label-free and real-time synchronized monitoring of extracellular matrix proteolysis using quartz crystal microbalance and nanoplasmonic sensing with morphological validation by atomic force microscopy.

Michal Szczepanczyk, Juan F Gonzalez-Martinez, Tautgirdas Ruzgas, Sebastian Björklund.

AIM: Understanding the interactions between extracellular matrix (ECM) proteins and proteases is essential for elucidating the mechanisms of ECM remodeling in both health and disease. The integration of real-time, label-free, and surface-sensitive techniques based on distinct physical principles enables detailed characterization of protease activity at the ECM substrate-liquid interface. Based on these kinds of techniques, this study focuses on investigating the dynamic interactions between protein adlayers and proteases, offering new insights into complex ECM remodeling processes.
EXPERIMENTS: The adsorption behavior and resulting adlayer properties of collagen and elastin, used as ECM model substrates, and the proteolytic activity of collagenase and elastase, were studied using synchronized quartz crystal microbalance with dissipation monitoring (QCM-D) and localized surface plasmon resonance (LSPR). Changes in adsorbed mass, viscoelastic properties, and near-surface dielectric environment were monitored via shifts in frequency (Δf), energy dissipation (ΔD), and plasmon resonance peak (∆λ), respectively. Atomic force microscopy (AFM) was employed to validate film morphology and mechanical alterations before and after proteolytic digestion.
FINDINGS: While the QCM-D/LSPR signals both detect mass uptake during protein adsorption and mass loss during proteolysis, synchronized measurements, complemented with AFM imaging, reveal more complex responses arising from the differing surface sensitivities of the techniques. Our integrated analysis show substantial differences in adlayer morphology and proteolytic degradation. Collagen forms a vertically heterogeneous adlayer with a dense near-surface layer and a highly viscoelastic outer layer of protruding fibrils (Δf ≈ -100 to -240 Hz, ΔD ≈ 40-70 ppm, and ∆λ ≈ 0.7 nm), whereas elastin adsorbs as a thinner, more rigid film (Δf ≈ -36 to -40 Hz, ΔD ≈ 2-3 ppm, and ∆λ ≈ 0.4 nm). Real-time monitoring reveals that collagenase primarily degrades the protruding collagen fibrils, significantly affecting all QCM-D and LSPR signals-particularly showing a clear overtone dependence in ΔD and Δf shifts-while elastase digestion of elastin occurs without overtone dependence and results in more pronounced changes in Δf and ∆λ, with comparatively low effect on ΔD. Cross-reactivity experiments confirm substrate specificity; however, both proteases show non-specific activity. Inhibition studies demonstrate that QCM-D can detect both true enzymatic inactivity and substrate-inhibitor interactions that mimic inhibition in conventional assays, for example by physically adsorbing to the substrate and thereby shielding it from proteolysis.

Keywords: Atomic force microscopy; Collagen; Collagenase; Elastase; Elastin; Extracellular matrix; Localized surface plasmon resonance; Proteases; Quartz crystal microbalance

DOI: https://doi.org/10.1016/j.jcis.2025.139139

J Mater Chem B. 2025 Oct 06.

Hydrolytic degradation of PEG-based thiol-norbornene hydrogels enables multi-modal controlled release.

Nathan H Dimmitt, Chien-Chi Lin.

Poly(ethylene glycol) (PEG) hydrogels crosslinked by orthogonal thiol-norbornene click chemistry have emerged as an ideal platform for tissue engineering and drug delivery applications due to their rapid crosslinking kinetics and excellent biocompatibility. Norbornene-functionalized PEG (PEGNB) is routinely synthesized through the Steglich esterification of 5-norbornene-2-carboxylic acid with hydroxyl-terminated PEG. When crosslinked with thiol-bearing macromers, PEGNB hydrogels undergo slow hydrolytic degradation due to hydrolysis of ester bonds connecting a PEG backbone and a NB moiety. In prior work, we replaced the pungent and nauseous 5-norbornene-2-carboxylic acid with odorless carbic anhydride (CA) for synthesizing PEG-norbornene-carboxylate (PEGNBCA), a new macromer that could be readily photo-crosslinked into thiol-norbornene hydrogels with faster hydrolytic degradation than the PEGNB counterparts. In this contribution, we employed a modular approach to tune the hydrolytic degradation of PEGNBCA hydrogels over days to months. We first demonstrated the diverse crosslinking of PEGNBCA hydrogels using either photopolymerization or enzymatic crosslinking. We characterized the hydrolytic degradation of these hydrogels under different solution pH values and temperatures. Via adjusting crosslinker functionality and the ratio of fast-degrading PEGNBCA to slow-degrading PEGNB, tunable hydrolytic degradation of PEGNBCA hydrogels was achieved from under 2 days to over 3 months. Finally, we designed the highly tunable PEGNBCA hydrogels with varying mesh sizes, degradation rates, and covalent tethering of degradable linkers to afford long-term controlled release of model drugs.

DOI: https://doi.org/10.1039/d5tb01524c