Mechanobiology is a new branch of biology that combines engineering, physics, and biology. It examines how physical stresses and alterations in cell and tissue mechanical characteristics affect development, cell differentiation, physiology, and disease. Mechanical forces are felt and can be processed by cells to produce biological reactions. Mechanical forces in human tissues include joint movement, compressive pressures on cartilage and bone during exercise, and shear pressure on a blood artery during blood circulation. Understanding mechanotransduction—the molecular mechanisms by which cells receive and respond to mechanical signals—is a fundamental challenge in the science.
While advances in mechanobiology suggest that changes in cell mechanics, extracellular matrix structure, or mechanotransduction may contribute to the development of many diseases, including atherosclerosis, fibrosis, asthma, osteoporosis, heart failure, and cancer, medicine has traditionally looked for the genetic and biochemical basis of disease. Many widespread medical problems, such as lower back pain, foot and posture injuries, deformity, and irritable bowel syndrome, have a strong mechanical base. Mechanical signals such as tension, compression, and shear pressure affect skin fibroblasts, which are important in wound healing and development.
Fibroblasts produce structural proteins, some of which are mechanosensitive and are found in the Extracellular Matrix (ECM), such as collagen types I, III, IV, V, VI, elastin, and lamin, among others. Aside from structural proteins, fibroblasts produce Tumor Necrosis Factor-alpha (TNF-), Transforming Growth Factor-beta (TGF-), and matrix metalloproteases, which are involved in tissue maintenance and re-modelling. Articular cartilage is a lubricated connective tissue that protects the bones of load-bearing joints like the knee and shoulder. In response to compressive strain, it deforms, lowering bone stress. The biphasic structure of articular cartilage, which contains both solid and fluid phases, accounts for its mechanical reactivity. The fluid phase is composed of water (which accounts for 80% of the wet weight) and inorganic ions such as sodium, calcium, and potassium. Porous ECM makes up the solid phase. Negative electrostatic repelling forces interact with proteoglycans and interstitial fluids to provide compressive force to cartilage. Hydrostatic pressure is caused by the ion concentration differential between the extracellular and intracellular ions composition of chondrocytes. The mechanical environment of the joint determines the surface and topology of the joint throughout development.
Adults require moderate mechanical loading to maintain cartilage; joint immobilisation causes proteoglycan loss and cartilage atrophy, while excessive mechanical loading causes joint degeneration. Mechanical signals from the extracellular matrix are communicated through the cytoskeleton through linker of nucleoskeleton and Cytoskeleton (LINC)-associated proteins such KASH and SUN, and the nucleus responds.
The Ataxia Telangiectasia and Rad3-related (ATR) gene is translocated and activated to the nuclear periphery region in response to hyperosmotic stress, whereas cPLA2 is re-localized and activated to the nuclear membrane in response to hypoosmotic challenge and compression. Self-assembly is used to create the embryo, in which cells differentiate into tissues that execute specific activities. Only chemical signals were traditionally thought to provide cues for spatially oriented changes in cell growth, differentiation, and fate switching that drive morphogenetic regulation. This is predicated on the ability of chemical signals to cause biochemical responses in distant cells, such as tissue patterning. Mechanical forces created within cells and tissues, on the other hand, are now understood to give regulatory signals. Cells aggregate and the compactness between cells increases during the division of the fertilised egg, thanks to actomyosin-dependent cytoskeletal traction forces and their application to sticky receptors in nearby cells, resulting in the creation of solid balls known as Morula. Mechanical forces mediated by microtubules and the actin microfilament system determine spindle location within symmetrically and asymmetrically dividing cells in the early embryo.
The expression of genes that give birth to the embryonic developmental process of blastulation is also controlled by local variations in physical forces and mechanical signals such as the stiffness of the ECM. The lack of a transcription factor that regulates stiffness in the trophectoderm, Cdx causes ectopic expression of inner cell mass markers, and the pluripotent transcription factor Oct-4 may be negatively expressed, causing lineage flipping. The mechanosensitive hippo pathway controls cell fate switching. The efficacy of several mechanical therapies currently in clinical use demonstrates the importance of physical forces in physiological control. This point is shown by a number of cases. Premature newborns benefit from pulmonary surfactant, and adjusting the tidal volumes of mechanical ventilators lowers morbidity and mortality in patients with acute lung damage. Coronary artery constriction is physically prevented with expandable stents. Tissue expanders enlarge the amount of skin that can be used for reconstructive surgery. Bone fracture repair, orthodontics, cosmetic breast expansion, and the closure of non-healing wounds all require surgical tension application devices. Improved medical devices, biomaterials, and synthetic tissues for tissue repair and reconstruction may be developed as a result of new insights into the mechanical basis of tissue control. Stretch-activated ion channels, caveolae, integrins, cadherins, growth factor receptors, myosin motors, cytoskeletal filaments, nuclei, extracellular matrix, and countless other signalling molecules are among the known components to cellular mechanotransduction. Endogenous cellgenerated traction forces play a role in these responses by modifying tensional prestress inside cells, tissues, and organs, which governs mechanical stability and signal transmission from the macroscale to the nanoscale.
Citation: Roy S (2021) A Report on Mechanobiology. J Biomed Eng & Med Dev.6:197.
Received: 08-Nov-2021 Accepted: 22-Nov-2021 Published: 29-Nov-2021 , DOI: 10.35248/2475-75126.96.36.199
Copyright: © 2021 Roy S. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.