02116nas a2200193 4500008004100000245009500041210006900136260001200205520148600217653001901703100001501722700001701737700001401754700002501768700001401793700002001807700001801827856007701845 2017 eng d00aOn the adhesion-cohesion balance and oxygen consumption characteristics of liver organoids0 aadhesioncohesion balance and oxygen consumption characteristics  c03/20173 a

Liver organoids (LOs) are of interest in tissue replacement, hepatotoxicity and pathophysiological studies. However, it is still unclear what triggers LO self-assembly and what the optimal environment is for their culture. Hypothesizing that LO formation occurs as a result of a fine balance between cell-substrate adhesion and cell-cell cohesion, we used 3 cell types (hepatocytes, liver sinusoidal endothelial cells and mesenchymal stem cells) to investigate LO self-assembly on different substrates keeping the culture parameters (e.g. culture media, cell types/number) and substrate stiffness constant. As cellular spheroids may suffer from oxygen depletion in the core, we also sought to identify the optimal culture conditions for LOs in order to guarantee an adequate supply of oxygen during proliferation and differentiation. The oxygen consumption characteristics of LOs were measured using an O2 sensor and used to model the O2 concentration gradient in the organoids. We show that no LO formation occurs on highly adhesive hepatic extra-cellular matrix-based substrates, suggesting that cellular aggregation requires an optimal trade-off between the adhesiveness of a substrate and the cohesive forces between cells and that this balance is modulated by substrate mechanics. Thus, in addition to substrate stiffness, physicochemical properties, which are also critical for cell adhesion, play a role in LO self-assembly.

10aBioengineering1 aMattei, G.1 aMagliaro, C.1 aGiusti, S1 aRamachandran, S., D.1 aHeinz, S.1 aBraspenning, J.1 aAhluwalia, A. uhttp://journals.plos.org/plosone/article?id=10.1371/journal.pone.017320601665nas a2200133 4500008004100000245003200041210003100073260001200104490000600116520132700122653001901449100001801468856004501486 2017 eng d00aAllometric scaling in-vitro0 aAllometric scaling invitro c02/20170 v73 a

About two decades ago, West and coworkers established a model which predicts that metabolic rate follows a three quarter power relationship with the mass of an organism, based on the premise that tissues are supplied nutrients through a fractal distribution network. Quarter power scaling is widely considered a universal law of biology and it is generally accepted that were in-vitro cultures to obey allometric metabolic scaling, they would have more predictive potential and could, for instance, provide a viable substitute for animals in research. This paper outlines a theoretical and computational framework for establishing quarter power scaling in three-dimensional spherical constructs in-vitro, starting where fractal distribution ends. Allometric scaling in non-vascular spherical tissue constructs was assessed using models of Michaelis Menten oxygen consumption and diffusion. The models demonstrate that physiological scaling is maintained when about 5 to 60% of the construct is exposed to oxygen concentrations less than the Michaelis Menten constant, with a significant concentration gradient in the sphere. The results have important implications for the design of downscaled in-vitro systems with physiological relevance.

10aBioengineering1 aAhluwalia, A. uhttp://www.nature.com/articles/srep4211302265nas a2200229 4500008003900000245008800039210006900127260002700196300000700223520152800230653001901758100001801777700001401795700001401809700001801823700001401841700001501855700001401870700001401884700001701898856012001915 2014 d00aAutonomous bioreactor modules for disease models and detection of systemic toxicity0 aAutonomous bioreactor modules for disease models and detection o aPrague, Czech Republic a433 a

Advanced systems based on bioreactors and scaffolds are an essential step towards the development of more predictive and ethical alternatives to animal experiments. Size, modularity, automation, monitoring and essential design are crucial because these elements will ease the transition from old technology and accelerate their acceptance into mainstream research. Based on these requirements, the interconnected transparent sensorised “lego” bioreactors designed in our labs have been used to generate physiologically relevant disease and toxicity models which recapitulate systemic responses impossible to observe in standard cell cultures. The disease model is an interconnected bioreactor circuit with i) adipose tissue in 3D in 3 different concentrations representing normo-weight, over weight and obese body mass indices, ii) human hepatocytes on porous collagen scaffolds and iii) monolayers of human endothelial cells. High adiposity and elevated glucose levels induce systemic and endothelial inflammation in the circuit, as observed in overweight and diabetic humans (Iori et al., 2012). Using similar technology a three-tissue circuit for monitoring the absorption, distribution, metabolism and toxicity of nanoparticles was developed in the context of the EU project InLiveTox (Ucciferri et al., 2014). The results were strikingly similar to those observed in animal experiments demonstrating that the dynamic 3D in-vitro models are ethical, meaningful and economically viable replacements.

10aBioengineering1 aAhluwalia, A.1 aGiusti, S1 aSbrana, T1 aWilkinson, M.1 aMisto, A.1 aLehr, C -M1 aLiley, M.1 aHorst, S.1 aJírová, D. uhttp://95.110.227.16/publications/autonomous-bioreactor-modules-disease-models-and-detection-systemic-toxicity.html00826nas a2200253 4500008004100000022001400041245012100055210006900176300001600245490000700261653001900268100001300287700001500300700001400315700001400329700001300343700001800356700001400374700001500388700001400403700001900417700001900436856011700455 2007 eng d a0953-816X00aAcute retinal ganglion cell injury caused by intraocular pressure spikes is mediated by endogenous extracellular ATP0 aAcute retinal ganglion cell injury caused by intraocular pressur a2741–27540 v2510aBioengineering1 aRESTA, V1 aNOVELLI, E1 aVozzi, G.1 aSCARPA, C1 aCALEO, M1 aAhluwalia, A.1 aSOLINI, A1 aSANTINI, E1 aPARISI, V1 aDI VIRGILIO, F1 aGALLI-RESTA, L uhttp://95.110.227.16/publications/acute-retinal-ganglion-cell-injury-caused-intraocular-pressure-spikes-mediated