Over the years, researchers have tried hard to comprehend topographic signals that promote cell mechanical sensitive responses. The extracellular matrix (ECM) provides a complex cellular microenvironment that controls cellular behavior. Nevertheless, only a few functions of these factors are understood, and most remain obscure.
An article published in Advanced Sciences presented a convenient method to demonstrate the curved structure of the ECM network that regulates stem cell mechanotransduction. Here, an ECM-mimicking nanofiber network was prepared using electrospinning technology.
Figure 1. Fabrication and characterization of the curved and straight nanofiber network. a) The Representative images of masson staining of the periodontal tissues. b) The SEM (left) image of the decellularized periodontal ligament tissues and the representative fluorescence image of the collagen I and II (right) in periodontal tissues. c) Scheme of the curved and straight nanofiber network fabrication. The curved and straight fiber network require 0 °C and 25 °C electrospinning temperature, respectively. d) The representative SEM images of the curved and straight fibers (three technical replicates). e) The diameter of the ECM fibers in the periodontal tissues and the artificial fibers (n = 100, two technical replicates). f) Young’s modulus of the curved and straight nanofiber network as detected by Nanoindenter (n = 20, two technical replicates). g) Specific surface area of the curved and straight surfaces as detached by the fluorescent intensity of the adsorbed FITC-BSA at 562 nm (n = 12, two technical replicates). h) The average curvature of the ECM fibers in the periodontal tissues and the artificial fibers (n = 160, two technical replicates). i) The orientation angles (n = 100, two technical replicates) of the curved and straight fibers.
The curved nanofiber promoted cell bridge formation due to cytoskeleton tension. Moreover, the myosin-II-based intracellular force generated by the actomyosin filaments inclined the cell lineage towards osteogenic differentiation. Thus, the present study has provided a better understanding of the effects of topographic signals on cell behavior, thereby aiding the development of new biomaterials.
Effect of Nanofibers on the Functioning of Stem Cells
According to recent studies, the physiological and behavioral functions of cells are influenced by biochemical and physical factors. Novel biomaterials that mimic ECM’s stiffness, degradation, ligand diffusion, stress relaxation, and other physical properties, in addition to the usual chemical effects, have been created.
Nanomaterials, such as nanofibers, are mostly fabricated through electrospinning. In this process, a strong electric field is used to transform solution-based polymers into continuous nanometer-sized fibers.
Various nanofibers differ in their properties, including surface-to-volume ratio and morphology. These characteristics can be altered based on the polymer and intended application. The electrospinning parameters, solution parameters, and ambient characteristics affect the properties of the nanofibers.
Stem cells can develop into various cell types and construct any tissue in the body. However, stem cells have low vitality and are challenging to multiply, which limits their application for a wider range of prospective therapeutic benefits.
Stem cells and electrospun nanofibers have two key advantages. First, by changing the chemical characteristics of the nanofibers to enhance their interactions with stem cells, they can operate as advantageous scaffolds for maintaining stem cells. Second, stem cells can be delivered using nanofibers to particular tissues or organs for tissue engineering and wound repair.
Previous reports have suggested that cancer cells unbend the curled collagen fibers in the ECM during tumor growth. Although curved structures in the fibrous connective tissue, known as the periodontal ligament, were previously known, their function at the cellular level remains unclear. Moreover, studies in this area have been restricted by the absence of techniques for creating curved nanofibers.
Curved Nanofibers to Promote Stem Cell Mechanotransduction
Despite previous reports on electrospinning technology to fabricate biomaterials that mimic the ECM, only a few reports have described the fabrication of curved nanofibers. On the other hand, other studies that carried out low-temperature electrospinning have focused on the porosity of the matrix rather than the topology of nanofibers.
In this study, cryogenic electrospinning technology was utilized to fabricate ECM-mimicking curved nanofibers as a tool to study cell response when exposed to curved structures. Interestingly, curved nanofibers influenced the behavior of stem cells, altering their adhesive nature compared to straight nanofibers.
While cells adhered along straight nanofibers, they crossed curved nanofibers to form cell bridges, indicating that the cell bodies overhung instead of attaching to the nanofibers.
The formation of cell bridges rearranged the distribution of the actomyosin cytoskeleton and imparted extra intracellular force, enhancing stem cell mechanotransduction and promoting osteogenic differentiation. The new findings of this study helped obtain a better understanding of the crucial role of biomechanical principles in promoting the development of tissue engineering.
Thus, the present investigation of cell mechanosensing revealed that, while the cell boundary was frequently parallel to the surrounding straight nanofibers, it invariably traversed multiple curved nanofibers as bridges. The cells on the curved nanofibers had a significant percentage of unbound borders that formed large radial arcs that bowed inwards.
Figure 3. Immunofluorescence staining displays widely distributed cell bridges in the periodontal ligament. a) The representative fluorescence images of nuclei (blue), F-actin (green), and collagen I (red) staining of the mouse periodontal ligament. b) Canny edge test image of the yellow box area in (a). The magenta and green represent the collagen I and F-actin, respectively. c) The average curvature of the cell edges (n = 50, two technical replicates) of the cells in periodontal ligament and cultured on the artificial fibers.
Conclusion
In summary, a simple electrospinning technology that operates at a low speed and temperature to fabricate ECM-mimicking curved nanofiber structures was developed. While the curved nanofibers promoted discrete adhesion in stem cells, straight networks induced the formation of continuous adhesion by stem cells along with the fiber structure.
The curved nanofibers stimulated stem cell mechanotransduction by forming a cell bridge, thereby promoting osteogenic differentiation and proliferation of stem cells. Inducing mechanotransduction and mechanosensing signaling pathways via the formation of nonadhesive bridges caused actomyosin to aggregate and contract.
Thus, the present study demonstrated that the knowledge of cell mechanosensing and tissue development could be improved by using this curved matrix to enhance the database of biomaterials that mimic the ECM.

News
Does Space-Time Really Exist?
Is time something that flows — or just an illusion? Exploring space-time as either a fixed “block universe” or a dynamic fabric reveals deeper mysteries about existence, change, and the very nature of reality. [...]
Unlocking hidden soil microbes for new antibiotics
Most bacteria cannot be cultured in the lab-and that's been bad news for medicine. Many of our frontline antibiotics originated from microbes, yet as antibiotic resistance spreads and drug pipelines run dry, the soil [...]
By working together, cells can extend their senses beyond their direct environment
The story of the princess and the pea evokes an image of a highly sensitive young royal woman so refined, she can sense a pea under a stack of mattresses. When it comes to [...]
Overworked Brain Cells May Hold the Key to Parkinson’s
Scientists at Gladstone Institutes uncovered a surprising reason why dopamine-producing neurons, crucial for smooth body movements, die in Parkinson’s disease. In mice, when these neurons were kept overactive for weeks, they began to falter, [...]
Old tires find new life: Rubber particles strengthen superhydrophobic coatings against corrosion
Development of highly robust superhydrophobic anti-corrosion coating using recycled tire rubber particles. Superhydrophobic materials offer a strategy for developing marine anti-corrosion materials due to their low solid-liquid contact area and low surface energy. However, [...]
This implant could soon allow you to read minds
Mind reading: Long a science fiction fantasy, today an increasingly concrete scientific goal. Researchers at Stanford University have succeeded in decoding internal language in real time thanks to a brain implant and artificial intelligence. [...]
A New Weapon Against Cancer: Cold Plasma Destroys Hidden Tumor Cells
Cold plasma penetrates deep into tumors and attacks cancer cells. Short-lived molecules were identified as key drivers. Scientists at the Leibniz Institute for Plasma Science and Technology (INP), working with colleagues from Greifswald University Hospital and [...]
This Common Sleep Aid May Also Protect Your Brain From Alzheimer’s
Lemborexant and similar sleep medications show potential for treating tau-related disorders, including Alzheimer’s disease. New research from Washington University School of Medicine in St. Louis shows that a commonly used sleep medication can restore normal sleep patterns and [...]
Sugar-Coated Nanoparticles Boost Cancer Drug Efficacy
A team of researchers at the University of Mississippi has discovered that coating cancer treatment carrying nanoparticles in a sugar-like material increases their treatment efficacy. They reported their findings in Advanced Healthcare Materials. Over a tenth of breast [...]
Nanoparticle-Based Vaccine Shows Promise in Fighting Cancer
In a study published in OncoImmunology, researchers from the German Cancer Research Center and Heidelberg University have created a therapeutic vaccine that mobilizes the immune system to target cancer cells. The researchers demonstrated that virus peptides combined [...]
Quantitative imaging method reveals how cells rapidly sort and transport lipids
Lipids are difficult to detect with light microscopy. Using a new chemical labeling strategy, a Dresden-based team led by André Nadler at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) and [...]
Ancient DNA reveals cause of world’s first recorded pandemic
Scientists have confirmed that the Justinian Plague, the world’s first recorded pandemic, was caused by Yersinia pestis, the same bacterium behind the Black Death. Dating back some 1,500 years and long described in historical texts but [...]
“AI Is Not Intelligent at All” – Expert Warns of Worldwide Threat to Human Dignity
Opaque AI systems risk undermining human rights and dignity. Global cooperation is needed to ensure protection. The rise of artificial intelligence (AI) has changed how people interact, but it also poses a global risk to human [...]
Nanomotors: Where Are They Now?
First introduced in 2004, nanomotors have steadily advanced from a scientific curiosity to a practical technology with wide-ranging applications. This article explores the key developments, recent innovations, and major uses of nanomotors today. A [...]
Study Finds 95% of Tested Beers Contain Toxic “Forever Chemicals”
Researchers found PFAS in 95% of tested beers, with the highest levels linked to contaminated local water sources. Per- and polyfluoroalkyl substances (PFAS), better known as forever chemicals, are gaining notoriety for their ability [...]
Long COVID Symptoms Are Closer To A Stroke Or Parkinson’s Disease Than Fatigue
When most people get sick with COVID-19 today, they think of it as a brief illness, similar to a cold. However, for a large number of people, the illness doesn't end there. The World [...]