Investigation of cellular morpho-mechanical alteration as a novel diagnostic tool in nanomedicine

For several decades, the relationship between biomechanics and medicine has been the subject of considerable attention from the scientific community, in order to establish a connection between cellular structure, biological function, mechanical properties, and health/disease status [1][2]. Currently, mechanobiology is one of the emerging fields of basic research, focusing firstly on understanding the role played by physical forces play in the signaling of stimuli and the correspondent regulation of cellular functions; secondly on the involvement of such forces in more complex processes, such as tissue and organ development, and ultimately on the origin and progression of the disease [3]. Cells constitute the fundamental units of all living organisms; and their architecture varies according to the biological function they perform. The fulfilment of physiological functions is regulated by a series of intra- and extracellular events, many of which involve mechanical phenomena. Cells are indeed living mechanical entities that exist in a constant dynamic equilibrium of forces: inner forces, generated by the pulling capacity of the actin cytoskeleton; resisting forces, counterbalancing the inner forces in the extracellular matrix (ECM). Vice versa, changes in stiffness or organization of the ECM impose cells to respond by restructuring their cytoskeleton and inner tension until a new equilibrium is achieved (Fig. 1). Cells are continually subjected to mechanical stimuli, such as shear forces (due to the flow of air or blood), compression forces (due to cell movement through tissues), and tension (transmitted from adherent cells or the ECM) [4] [5]. Cells respond to these forces by adjusting their shape, internal organization, and behavior, through the activation of biochemical pathways which induces downstream responses, including alterations in the activity of the transmembrane proteins (channel proteins) and up- or down-regulation of the specific gene expression [6][7]. Any unbalance of this response equilibrium reflects a deviation from normal tissue architecture and is indeed a common feature of the disease.