Biology subjects

REYNAUD, E. G.

Publications and source records attributed to REYNAUD, E. G..

3 recordsLinked to original sources

bioRxiv2023

The Use of Fluid-phase 3D Printing to Pattern Alginate-gelatin Hydrogel Properties to Guide Cell Growth and Behaviour In Vitro

3D (bio)printing technology has boosted the advancement of the biomedical field. However, tissue engineering is in its infancy and (bio)printing biomimetic constructions for tissue formation in vitro is still a default. As a new methodology to improve in vitro studies, we suggest the use of a cross-linkable aqueous support bath to pattern the characteristics of the scaffolds during the 3D printing process. Using fluid-phase, different molecules can be added to specific locations of the substrate promoting cell behaviour guidance and compartmentalization. Moreover, mechanical aspects can be customized by changing the type or concentration of the solution in which the (bio)printing is acquired. In this study, we first assessed different formulations of alginate/gelatin to improve cell colonization in our printings. On formulations with lower gelatin content, the U2OS cells increased 2.83 times the cell growth. In addition, the alginate-gelatin hydrogel presented a good printability in both air and fluid-phase, however the fluid-phase printings showed better printing fidelity as it diminished the collapsing and the spreading of the hydrogel strand. Next, the fluid-phase methodology was used to guide cell colonization in our printings. First, different stiffness were created by crosslinking the hydrogel with different concentrations of CaCl2 during the printing process. As a result, the U2OS cells were compartmentalized on the stiffer parts of the printings. In addition, using fluid-phase to add RGD molecules to specific parts of the hydrogel has also promoted guidance on cell growth. Finally, our results showed that by combining stiffer alginate-gelatin hydrogel with RGD increasing concentrations we can create a synergetic effect and boost cell growth by up to 3.17-fold. This work presents a new printing process for tailoring multiple parameters in hydrogel substrates by using fluid-phase to generate a more faithful replication of the in vivo environment.

bioengineering↗

bioRxiv2023

Rise of the Cybercrabs: how digital cloning in an integrated taxonomic framework can support deep-sea exploration

Taxonomy has been a labour-intensive field of expertise based on hours of manual work and lengthy comments that are mainly bound to books and publications on a two-dimensional world. But every species described is a three-dimensional organism that needs to be seen, manipulated to be fully understood in its native shape. Nowadays, digital technology allows us to transform everyone in an avatar or a digital clone with ease, but collections do not provide many type specimens in a digital format. Here we present a simple approach used to study a specific deep-sea crab Segonzacia mesatlantica and provide online digital taxonomy across four repository sites. This offers the possibility to describe, exchange digitally and analyse specimens in its full 3D, establish their taxonomy and share them widely on online databases as well as physically by additive manufacturing to duplicate them in collections and outreach activities. Using an integrated taxonomic approach that included the use of 3D type specimens and molecular barcoding we provide evidence that the genus Segonzacia may be more diverse than previously understood

zoology↗

bioRxiv2018

Taxonomic revision of Leopold and Rudolf Blaschka Glass Models of Invertebrates 1888 Catalogue, with correction of authorities

The glass models of invertebrates crafted by Leopold and Rudolf Blaschka were made between 1863 and 1889. Production ceased when the glassmakers turned their attention to what is now known as the Ware Collection of Blaschka Glass Models of Plants, created for the Harvard Museum of Natural History. Nearly 130 years have passed since their last published catalogue of species in 1888 and the nomenclature they applied is now a confusing mix that includes many junior synonyms and unavailable names. This is an issue for many museums and universities which owns Blaschka models as uncertain identifications may compromised interpretation of this rediscovered legacy. Nowadays, many museums and universities hold collections of those glass invertebrates but misspelled, mislabelled or simply apply the century old taxonomy of 1888. Here, we provide a valuable resource for curators and enthusiasts alike. We studied and updated the final catalogue 1888 from the Blaschkas Dresden-based workshop. We first focused on major taxonomical changes from taxa to species, as well as on an analysis of the acknowledged authorities. We found that only 35.3% of the models retain their original names, while 3.7% lack any known synonym and their identity remains open to interpretation. Finally, two of the authorities listed in the catalogue, Ernst Haeckel and Philip Henry Gosse, were incorrectly acknowledged for an extensive range of models. This study is the first of its kind on the Blaschka collection, and it will help in the identification and naming of Blaschka models worldwide.

scientific communication and education↗