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Modelling the electrical activity of a cardiac pacemaker cell
Contributed by Stefano SeveriThe sinoatrial node (SAN) is the normal pacemaker of the mammalian heart. Over several decades, a large amount of data on the ionic mechanisms underlying the spontaneous electrical activity of SAN pacemaker cells has been obtained, mostly in experiments on single cells isolated from rabbit SAN. This allowed the development of comprehensive mathematical models of the electrical activity of ...
Proper mechanical loadings prime a specific tissue differentiation
Contributed by Joseph LovecchioDuring bone regeneration, intermediate tissues - such as fibrous connective tissue, cartilage and woven bone - precede final bone formation, providing initial mechanical stability and a scaffold for tissue differentiation. The mechanical loading affects the regeneration process, with different stress distribution favouring, or inhibiting, differentiation of specific tissue phenotypes. High ...
A 3D multiphase stem cell-based construct
Contributed by Giovanna Della PortaSchematic illustration of a 3D multiphase stem cell-based construct. The scaffold is formed by fibrin hydrogel coating a hyaluronate braided band to embed a) human-bone marrow mesenchimal stem cells (hBMSCs – yellow baby octopuses) and b) poly-lactide-co-glycolide (PLGA) microcarriers (green marbles) loaded with human-growth differentiation factor 5 (hGDF-5) into a multiphase deformable ...
Mammalian synthetic biology
Contributed by Francesca CeroniMammalian cells are important tools for bioprocessing applications and for investigating the mechanisms of cancer development. Although a close relation has been observed in these systems between cellular growth and the production of intracellular resources needed for transcription and translation, quantitative empirical relations are still lacking. Investigating the links among cell ...
Phenotypic variability in synthetic biology applications
Contributed by Emanuele GiordanoThe stochasticity due to the infrequent collisions among low copy-number molecules within the crowded cellular compartment is a feature of living systems. Single cell variability in gene expression within an isogenic population (i.e. biological noise) is usually described as the sum of two independent components: intrinsic and extrinsic stochasticity. Intrinsic stochasticity arises from the ...
Mathematical models predict the behavior of modular synthetic gene circuits
Contributed by Emanuele GiordanoMost of synthetic circuits developed have been designed by an ad hoc approach, using a small number of components (i.e. LacI, TetR) and a trial and error strategy. We are at the point where an increasing number of modular, inter-changeable and well-characterized components is needed to expand the construction of synthetic devices and to allow a rational approach to the design. The use of ...
Synthetic post-transcriptional control of gene expression
Contributed by Emanuele GiordanoPost-transcriptional regulation allows a faster control of gene expression, which might result relevant in the design of synthetic gene circuits. However, synthetic biologists are warned to give the proper consideration to functional modularity of biological parts and the need for a case-to-case characterization of their function, raising concern about the use of a overconfident bottom-up ...
Automatic quantification of (cancer) cell invasiveness
Contributed by Marilisa CortesiQuantification of (cancer) cell invasiveness can be obtained through the "scratch wound healing assay", a simple experimental framework evaluating the rate at which the tested cells are able to fill a gap expressly produced in a confluent culture. Despite its being widely used, the approaches used to analyse this in-vitro assay lack standardization and do not allow for an accurate and objective ...
Quantification of fluorescent protein markers in single bacterial cell
Contributed by Marilisa CortesiThe evaluation of phenotypic variability within an isogenic population of bacterial cells, requires the quantification of gene expression at single cell level. Flow cytometers and microscopy set-ups equipped with microfluidic devices and incubation chambers are instruments capable of evaluating the level of specific proteins in individual cells. However they are expensive and generally ...