Determining the three-dimensional structure of two demosponges for bioprinting purposes

Details

Supervisors

Rees, Jean-François

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en chimie et bioindustries, à finalité spécialisée

Abstract

The overall aim of the project is to develop precise, reproducible bioprinting methods for marine sponge tissues. This would enable their potential to be exploited as a source of pharmaceutical compounds and tissue reconstruction materials, as current production methods are not suitable for industrial use. This master thesis investigates the determination of the three-dimensional structure of two species of marine demosponges, Haliclona simulans and Hymeniacidon perlevis, using two advanced imaging techniques, X-ray computed tomography (microCT) and confocal microscopy (CLSM). MicroCT was used to obtain a three-dimensional representation of the sponge's various constituents with a resolution down to a few micrometers. This technique has revealed the network of aquifer canals, the interconnection between the skeleton and soft tissues, the porosity, and the sediment accumulation on the surface and within the sponge. Furthermore, it has also quantified the volume of several components. Specific protocols have been established to optimize the quality of the results obtained. However, further research is needed to further improve this process and obtain more representative data. The findings obtained through these techniques have revealed significant differences in the three-dimensional structure between the two species. H. simulans exhibited a higher ratio of void space to the total volume of the sponge due to its thicker canals, while H. perlevis had a higher ratio of tissues to the total volume. Confocal microscopy using primary and secondary antibodies allowed for the labeling of choanocyte flagella with anti-acetylated alpha tubulin and cell nuclei with DAPI. This method revealed choanocyte chambers, essential for water filtering and sponge nutrition. These structures were observed in the central part of H. simulans, and emergent chambers were observed in primmorphs of the same species. However, a more in-depth analysis of the overall organization of the various chambers remains to be carried out in order to determine their precise arrangement and interaction. Furthermore, an analysis to be conducted involves bioprinting sponge tissues with void spaces to investigate the spontaneous formation of choanocyte chambers. Further development of skills in cell culture is necessary to establish continuous cell lines, which will enable the bioprinting of sponge tissue. Additionally, the formulation of bioinks and the exploration of different cell types are essential for successful bioprinting. Finally, it is crucial to find a balance between the accuracy of the model and resource constraints, such as computational power and the capabilities of the bioprinter.