Growth and remodelling of living tissues: perspectives, challenges and opportunities.

One of the most remarkable differences between classical engineering materials and living matter is the ability of the latter to grow and remodel in response to diverse stimuli. The mechanical behaviour of living matter is governed not only by an elastic or viscoelastic response to loading on short time scales up to several minutes, but also by often crucial growth and remodelling responses on time scales from hours to months. Phenomena of growth and remodelling play important roles, for example during morphogenesis in early life as well as in homeostasis and pathogenesis in adult tissues, which often adapt to changes in their chemo-mechanical environment as a result of ageing, diseases, injury or surgical intervention.

Mechano-biological model of glioblastoma cells in response to osmotic stress.

This work investigates the mechano-biological features of cells cultured in monolayers in response to different osmotic conditions. In-vitro experiments have been performed to quantify the long-term effects of prolonged osmotic stresses on the morphology and proliferation capacity of glioblastoma cells. The experimental results highlight that both hypotonic and hypertonic conditions affect the proliferative rate of glioblastoma cells on different cell cycle phases.

Time-dependent traction force microscopy for cancer cells as a measure of invasiveness.

The migration of tumor cells of different degrees of invasivity is studied, on the basis of the traction forces exerted in time on soft substrates (Young modulus∼10 kPa). It is found that the outliers of the traction stresses can be an effective indicator to distinguish cancer cell lines of different invasiveness. Here, we test two different epithelial bladder cancer cell lines, one invasive (T24), and a less invasive one (RT112).

Trends in biomedical engineering: focus on Patient Specific Modeling and Life Support Systems.

Over the last twenty years major advancements have taken place in the design of medical devices and personalized therapies. They have paralleled the impressive evolution of three-dimensional, non invasive, medical imaging techniques and have been continuously fuelled by increasing computing power and the emergence of novel and sophisticated software tools. This paper aims to showcase a number of major contributions to the advancements of modeling of surgical and interventional procedures and to the design of life support systems.

Force transmission in migrating cells.

During cell migration, forces generated by the actin cytoskeleton are transmitted through adhesion complexes to the substrate. To investigate the mechanism of force generation and transmission, we analyzed the relationship between actin network velocity and traction forces at the substrate in a model system of persistently migrating fish epidermal keratocytes. Front and lateral sides of the cell exhibited much stronger coupling between actin motion and traction forces than the trailing cell body.

Cell adhesion mechanisms and stress relaxation in the mechanics of tumours.

Tumour cells usually live in an environment formed by other host cells, extra-cellular matrix and extra-cellular liquid. Cells duplicate, reorganise and deform while binding each other due to adhesion molecules exerting forces of measurable strength. In this paper, a macroscopic mechanical model of solid tumour is investigated which takes such adhesion mechanisms into account.

Modeling the early stages of vascular network assembly.

In vertebrates, networks of capillary vessels supply tissues with nutrients. Capillary patterns are closely mimicked by endothelial cells cultured on basement membrane proteins that allow single randomly dispersed cells to self-organize into vascular networks. Here we provide a model including chemoattraction as the fundamental mechanism for cell-to-cell communication in order to identify key parameters in the complexity of the formation of vascular patterns.