mastodon.xyz is one of the many independent Mastodon servers you can use to participate in the fediverse.
A Mastodon instance, open to everyone, but mainly English and French speaking.

Administered by:

Server stats:

788
active users

#adhesion

0 posts0 participants0 posts today

📰 "Invasive cancer cells soften collagen networks and disrupt stress-stiffening via volume exclusion, contractility and adhesion"
biorxiv.org/content/10.1101/20 #Extracellular #Mechanical #Adhesion

bioRxiv · Invasive cancer cells soften collagen networks and disrupt stress-stiffening via volume exclusion, contractility and adhesionCollagen networks form the structural backbone of the extracellular matrix in both healthy and cancerous tissues, exhibiting nonlinear mechanical properties that crucially regulate tissue mechanics and cell behavior. Here, we investigate how the presence of invasive breast cancer cells (MDA-MB-231) influences the polymerization kinetics and mechanics of collagen networks using bulk shear rheology and rheo-confocal microscopy. We show that embedded cancer cells delay the onset of collagen polymerization due to volume exclusion effects. During polymerization, the cells (at 4% volume fraction) cause an unexpected time-dependent softening of the network. We show that this softening effect arises from active remodeling via adhesion and contractility rather than from proteolytic degradation. At higher cell volume fractions, the dominant effect of the cells shifts to volume exclusion, causing a two-fold reduction of network stiffness. Additionally, we demonstrate that cancer cells suppress the characteristic stress-stiffening response of collagen. This effect (partially) disappears when cell adhesion and contractility are inhibited, and it is absent when the cells are replaced by passive hydrogel particles. These findings provide new insights into how active inclusions modify the mechanics of fibrous networks, contributing to a better understanding of the role of cells in the mechanics of healthy and diseased tissues like invasive tumors. ### Competing Interest Statement The authors have declared no competing interest.

Anti-Icing Polar Bear Fur

Despite spending their lives in and around frigid water, snow, and ice, polar bears are rarely troubled by ice building up on their fur. This natural anti-icing property is one Inuits have long taken advantage of by using polar bear fur in hunting stools and sandals. In a new study, researchers looked at just how “icephobic” polar bear fur is and what properties make it so.

The key to a polar bear’s anti-icing is sebum — a mixture of cholesterol, diacylglycerols, and fatty acids secreted from glands near each hair’s root. When sebum is present on the hair, the researchers found it takes very little force to remove ice; in contrast, fur that had been washed with a surfactant that stripped away the sebum clung to ice.

The researchers are interested in uncovering which specific chemical components of sebum impart its icephobicity. That information could enable a new generation of anti-icing treatments for aircraft and other human-made technologies; right now, many anti-icing treatments use PFAS, also known as “forever chemicals,” that have major disadvantages to human and environmental health. (Image credit: H. Mager; research credit: J. Carolan et al.; via Physics World)

📰 "Focal adhesion in the tumour metastasis: from molecular mechanisms to therapeutic targets"
doi.org/doi:10.1186/s40364-025
pubmed.ncbi.nlm.nih.gov/400453
#Extracellular #Mechanical #Adhesion

BioMed CentralFocal adhesion in the tumour metastasis: from molecular mechanisms to therapeutic targets - Biomarker ResearchThe tumour microenvironment is the “hotbed” of tumour cells, providing abundant extracellular support for growth and metastasis. However, the tumour microenvironment is not static and is constantly remodelled by a variety of cellular components, including tumour cells, through mechanical, biological and chemical means to promote metastasis. Focal adhesion plays an important role in cell-extracellular matrix adhesion. An in-depth exploration of the role of focal adhesion in tumour metastasis, especially their contribution at the biomechanical level, is an important direction of current research. In this review, we first summarize the assembly of focal adhesions and explore their kinetics in tumour cells. Then, we describe in detail the role of focal adhesion in various stages of tumour metastasis, especially its key functions in cell migration, invasion, and matrix remodelling. Finally, we describe the anti-tumour strategies targeting focal adhesion and the current progress in the development of some inhibitors against focal adhesion proteins. In this paper, we summarize for the first time that focal adhesion play a positive feedback role in pro-tumour metastatic matrix remodelling by summarizing the five processes of focal adhesion assembly in a multidimensional way. It is beneficial for researchers to have a deeper understanding of the role of focal adhesion in the biological behaviour of tumour metastasis and the potential of focal adhesion as a therapeutic target, providing new ideas for the prevention and treatment of metastases.

📰 "A highly sensitive, self-adhesive, biocompatible DLP 3D printed organohydrogel for flexible sensors and wearable devices"
arxiv.org/abs/2502.17208 #Cond-Mat.Mtrl-Sci #Physics.App-Ph #Mechanical #Adhesion

arXiv.orgA highly sensitive, self-adhesive, biocompatible DLP 3D printed organohydrogel for flexible sensors and wearable devicesWith the increasing demand for personalized health monitoring, wearable sensors have gained attention in medical diagnostics and physiological tracking. Hydrogels, known for their mechanical properties and similarity to biological tissues, are ideal for flexible sensing. However, conventional hydrogels face challenges in stability, biocompatibility, adhesion, and long-term comfort, especially in dynamic conditions.This study presents a highly sensitive, self-adhesive, and biocompatible organohydrogel fabricated via DLP 3D printing. By integrating an entanglement-dominated crosslinking mechanism with chemical and physical crosslinking, the hydrogel achieves high elasticity, mechanical strength, and durability. Methacrylic anhydride-grafted \k{appa}-carrageenan serves as the primary network, with optimized grafting rates enhancing tensile properties and strain modulation. The copolymer network of MA-kappa-CA and ACMO benefits from steric hindrance effects, improving swelling integrity and long-term stability.Experimental results confirm sustained adhesion and structural integrity under prolonged skin exposure, making it suitable for extended wear. The hydrogel exhibits excellent tensile resilience, flexibility, and strain-sensing capabilities. In vitro studies validate its biocompatibility, supporting its biomedical potential. Furthermore, its integration into wearable smart devices demonstrates promise for cervical spine monitoring and sports rehabilitation. A CNN-based system enables real-time, multi-channel analysis of cervical motion, proving its viability as a high-sensitivity flexible sensor for health monitoring and injury prevention.The proposed DLP 3D-printed hydrogel offers significant applications in flexible electronics, wearable sensors, and biomedical technologies, paving the way for next-generation health-monitoring systems.

📰 "Advanced 3D-Printed Multiphasic Scaffold with Optimal PRP Dosage for Chondrogenesis of BM-MSCs in Osteochondral Tissue Engineering"
arxiv.org/abs/2502.11130 #Mechanical #Q-Bio.To #Adhesion

arXiv.orgAdvanced 3D-Printed Multiphasic Scaffold with Optimal PRP Dosage for Chondrogenesis of BM-MSCs in Osteochondral Tissue EngineeringIn osteochondral tissue engineering (OCTE), simultaneously regenerating subchondral bone and cartilage tissue presents a significant challenge. Multiphasic scaffolds were created and manufactured using 3D printing to address this issue. Excellent interfacial mechanical properties and biocompatibility enhance the growth and chondrogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs). The subchondral bone bottom layer is mimicked by incorporating varying concentrations of graphene oxide (GO) (0%, 1%, and 2% w/v) into a bioink composed of alginate (Alg) and gelatin (Gel). Based on evaluations of mechanical and biocompatibility properties, 1% GO is selected for further studies. Subsequently, the GO concentration is kept constant while varying the platelet-rich plasma (PRP) dosage in the multiphasic scaffolds. Different PRP dosages (0%, 1%, 2%, and 3% w/v) are integrated into the Alg-Gel bioink to simulate cartilage tissues. Results indicate that 3D-printed scaffolds containing 1% or 2% PRP exhibit favorable biomechanical properties, with no significant differences observed. However, BM-MSCs exposed to 2% PRP demonstrate enhanced adhesion, growth, and viability. Additionally, real-time PCR and Alcian blue staining confirm increased chondrogenic expression and glycosaminoglycans (GAGs) synthesis. This work highlights the promising potential of 3D-printed multiphasic frameworks in the development of OCTE.