Josep Samitier, Ph.D.
Professor, Department of Electronics and Biomedical Engineeering,
University of Barcelona
jsamitier@ibecbarcelona.eu
Biography：
Background in Physics (M.S. Degree in Physics, University of Barcelona and Ph.D. in Physics, University of Barcelona). Director of the Institute for Bioengineering of Catalonia (IBEC), Barcelona Institute for Science and Technology (BIST and Full Professor of Electronics and Biomedical Engineering. Engineering Department. University of Barcelona (UB). Group leader of the Nanobioengineering Group at IBEC. His main research areas are Biosensors, Microfluidics and Organ-on-chip. Prof. Samitier also has been member of the EIT Health Supervisory Board, coordinator of the Spanish Nanomedicine Platform (NanomedSpain), spanish delegate in the Working Party on Biotecnology (OECD) and president of the Catalan Association of Research Centres (Associació Catalana d'Entitats de Recerca - ACER).
Topic title：How control the architecture of 3D cellular tissues?
Abstract：Cell adhesion onto bioengineered surfaces is affected by several variables, including the former substrate derivatization process. The information arising from this environmental sensing is integrated into the cell machinery through receptor proteins located at the cell membrane. We have studied the correlation between cell adhesion and cell–adhesive ligand surface gradient concentration. To analyze in detail the nanoclustering effects in the cell adhesion and differentiation process, we have created large-scale uneven nanopatterns of arginine-glycine-aspartic acid (RGD)-functionalized dendrimers that permit the nanoscale control of local RGD surface density changing the initial dendrimer concentration. We have used this model to study the first steps of 3D chondrogenesis differentiation of mesenchymal stem cells (MSCs).
New biocompatible materials have enabled the direct 3D printing of complexes functional living tissues. However, it is difficult to obtain a single hydrogel that meets all desirable properties. Cell responsive bioinks are a critical component in bioprinting technology. Hydrogel-based bioinks encapsulating living cells and bioactive components are commonly used for bioprinting and a library of composite biomaterials to obtain versatile, lasting and mechanically tunable scaffolds are very suitable for cell co-culture and tissue modelling. In addition, these materials in combination with compartmentalized microfluidic culture systems, and human induced Pluripotent Stem Cells (hiPSCs) can be used to mimic complex physiological systems on health or in disease. We have used this model to study the maturation of 3D skeletal muscle tissue and the neuromuscular junction circuit
However, artificial hydrogels are far to reproduce completely all the stimulus of the physiological cell niche. A complementary approach is to engineer controlled three-dimensional (3D) matrices for the study of physiopathological processes in vitro using a confluent culture of “sacrificial” fibroblasts to deposit a complex network of fibrils, glycosaminoglycans and cytokines, which closely resembled the native stroma. These cells were seeded on top of microfabricated guiding templates to induce the 3D growth with controlled isotropic or anisotropic architectures. The resulting engineered matrices recapitulated the structure typically found in the native scenario, as well as the phenotypes and morphodynamics of numerous cell types.
We have used both approach to mimic 3D neuroblastoma tumors that is one of the most common solid cancers in childhood. Malignant neuroblastic cells are highly sensitive to the biomechanical properties of their microenvironment and that a stiff ECM can be generated and associated with aggressive neuroblastic tumors. The use of 3D cell culture with different stiffness could help us to better understand the effects of ECM on malignant cell behavior, as well as providing a way to simulate and better understand the biomechanical properties found in tumor tissues.
Acknowledgement
The Nanobioengineering group has support from the Commission for Universities and Research of the Department of Innovation, Universities, and Enterprise of the Generalitat de Catalunya (2017 SGR 1079) and is is part of the CERCA Programme / Generalitat de Catalunya. This work was partially supported by Project (RTI2018-097038-B-C21), funded by the Spanish Ministry of of Economy and Competitiveness under the National Program of R&D.
References
[1] Lagunas A. et al., Nanomedicine: Nanotechnology, Biology and Medicine Volume 9, Issue 5, Pages 694-701, July 2013.
[2] Lagunas, A. et al. Nano Res. 7: 399. (2014)
[3] Lagunas A et al. Nano Res. 10: 1959. (2017)
[4] Caballero D. et al. Advanced Functional Materials https://doi.org/10.1002/adfm.201702322 (2017)
[5] Caballero D. et al. Physical Biology, 10.1088/1478-3975/ab4549, 16, 6, (066009), (2019)
