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
A sceptical guide to AI agents in drug discovery
In conversation with Dr Eric Ma, Senior Principal Data Scientist at Moderna, Dr Raminderpal Singh examines what AI agents are actually good for, where the lock-in hides and why expertise has become more valuable [...]
Study identifies new targets for antiviral drugs against coronaviruses
A study led by researchers at the University of California San Diego School of Medicine and University of California, Riverside (UCR) School of Medicine has identified new targets for antiviral drugs against coronaviruses, including [...]
“Nearly Everybody Had Given Up” – Scientists Finally Solve a 60-Year Chemistry Mystery
After more than six decades of failed attempts, chemists have achieved a breakthrough involving a class of molecules long considered too unstable to isolate. Chemists have succeeded in isolating a group of molecules that [...]
Depression Symptoms Improved in Just 48 Hours After a Single Psychedelic Dose
A single dose of psilocybin produced rapid antidepressant effects in a small Swedish clinical trial, with improvements lasting for weeks. A single dose of psilocybin, the psychedelic compound found in magic mushrooms, produced rapid [...]
GHCE Concept
From the preface of the book Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artificial Intelligence, Edited by Frank Boehm: Since the publication of my first book (Nanomedical Device and Systems [...]
Human Bodies Are Producing Two Billion Tons of CO2 a Year
A new study reveals that the amount of carbon dioxide produced by human metabolism has increased dramatically over three decades. The carbon dioxide produced by human bodies as they convert food into energy increased [...]
A Hidden DNA Mechanism Could Explain How 20% of Human Cancers Develop
Researchers have identified an unexpected molecular vulnerability in cancers carrying BAF mutations. Mutations found in roughly 20% of human cancers may promote tumor growth by changing how DNA is organized inside cells. Researchers have [...]
Ebola kills over 5,300 in fastest-growing outbreak on record
Africa’s latest Ebola outbreak has killed nearly 5,400 people, the vast majority of them in the Democratic Republic of Congo (DRC), according to the continent’s top health agency. Africa Centres for Disease Control and [...]
China makes early progress in using sound waves to stimulate damaged brains
Chinese researchers are testing whether focused ultrasound can help restore consciousness in patients with severe brain injuries, adding to a growing international effort to use sound waves to stimulate deep brain structures without surgery. [...]
Micro-drones fly through the body thanks to ultrasound
At the EPFL, micro-drones have been developed that can be moved without a motor or battery.No motors, no batteries, no electronics on board, just small cavities that convert sound waves into thrust: this is [...]
A Single Enzyme Could Hold the Key to Treating a Devastating Brain Disorder
Blocking an enzyme’s production restored brain growth and healthy behaviors in mice engineered to develop Angelman syndrome, pointing to a possible treatment target. Children with Angelman syndrome begin to show difficulties with thinking and [...]
Scientists Develop a Clever New Way To Kill Cancer Cells From the Inside
Scientists have developed an experimental strategy that exploits a chemical byproduct of cancer cells to produce anticancer drugs directly inside them. Scientists in Japan have developed an experimental method that uses a chemical produced [...]
Our books are available worldwide!
Online Sellers other than Amazon, Routledge, and IOPP Indigo Global Health Care Equivalency in the Age of Nanotechnology, Nanomedicine and Artifcial Intelligence Global Health Care Equivalency In The Age Of Nanotechnology, Nanomedicine And Artificial [...]
After only a short training, people in a coma managed to send targeted signals
Researchers have succeeded in communicating with brain-injured patients who are unconscious. They see enormous potential in this for future treatments. Patients who lie motionless in bed after a severe brain injury and do not [...]
MIT Scientists Reprogram Immune Cells Inside the Body To Destroy Cancer
Natural killer cells reprogrammed inside mice eliminated lymphoma tumors and helped damaged livers heal, though whether this approach could help people with cancer or autoimmune disease remains unknown. To make a cancer treatment from [...]
Melanoma mRNA Vaccine Shows Promise in Preventing Disease Recurrence
Key takeaways: Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence [...]
