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PhD Discussions: Marc Azagra and Inês Sousa
Divendres, juliol 15, 2022 @ 10:00 am–12:00 pm
Novel Nuclear Magnetic Resonance (NMR) applications in the clinical field
Marc Azagra, Molecular Imaging for Precision Medicine Group
When nuclear magnetic resonance (NMR) was described more than half a century ago it appeared to be a curiosity of the quantum world. Since then NMR spectroscopy has become an essential tool not only for chemists, but also for biochemists, molecular biologists and even clinicians. Today we are going to explain what is Hyperpolarization NMR, main differences with thermal NMR acquisitions and two of the projects I am involved with: a new NMR application in clinical diagnosis stage for Liver disease and the first experiment ever performed with High-throughput Hyperpolarized Magnetic Resonance Imaging experiment with a multiwell microfluidic chips using Chemical Shift Imaging (CSI) pulse sequence.
Versatile gelatine-based biomaterials compatible with neuronal differentiation: Applications in different systems for brain modelling
Inês Sousa Pereira, Nanobioengineering Group
Tissue engineering has been focused on recreating the tissue environment of many organs, such as the brain, for modelling and for therapeutic approaches during the last years. Recently, 3D brain in vitro models have been explored as they resemble more accurately physiological conditions of this organ. However, neuronal cultures are challenging due to the high sensitivity of these cells to changes in their surroundings.
We present a hydrogel composed of methacrylated gelatine (GeIMA), alginate (AlgMA) and hyaluronic acid (HA) for neural progenitor cell culture in this work. Our goal was to assess the compatibility of GelMA and AlgMA composites with neuronal culture as these two materials are common in tissue engineering applications. HA was added to better mimic the stiffness of the brain tissue. Neuroprogenitor mouse cell line C17.2 was embedded in the gelatine-based formulations and cultured as 3D scaffold in a drop shape or inserted in a microfluidic device. They were also used as bioinks for extrusion bioprinting. We performed the physical characterization of both formulations, viability studies, immunostainings to assess the differentiation process and calcium imaging to validate the activity of the cells.
Results show that hydrogels with and without hyaluronic acid have good porosity, allowing nutrient and oxygen diffusion. They also present low Young Modulus, especially for hyaluronic acid formulation, rendering values similar to the brain tissue., the viability of the cells as well as the cell differentiation and connectivity were high after 28 days in culture In the assays with the formulations as scaffolds. The activity of the cells was assessed at day 8 and increased by day 15 for both formulations, showing that cells were differentiating, and the neuronal network was maturating. In the bioprinting assays, the formulations presented high cell viability up to 15 days after printing and day 15 immunostaining showed the expression of neuroprogenitor marker nestin and early neuron marker β-III tubulin. On 3D-brain on the chip assays, the both formulations had high cell viability up until day 15 of culture, increasing expression of β-III tubulin as well as cell activity.
In conclusion, our formulations allow long-term cell culture, including high expression of neuronal markers, cell connectivity and activity and the presence of HA gave the hydrogel physical characteristics closer to brain tissue while permitting a high cell viability and allowing the differentiation of C17.2 cells. These biomaterials are also suitable as bioinks for extrusion in a bioprinter as proven by the good viability of the cells and the compatibility with the differentiation process. The formulations were also tested in a microfluidic system, maintaining the viability, differentiation, and activity capacities of the cells. Overall, these results make these hydrogels a promising scaffold for brain modelling, applicable to 3D long-term culture and differentiation of cells, such as iPSC-derived neurons.
This PhD Discussion session will be held at Tower I, 11th floor Baobab room, at 10:00am.
