In this study porous gelatin scaffolds were prepared using in-situ gas foaming, and four crosslinking agents were used to determine a biocompatible and effective crosslinker that is suitable for such a method. Crosslinkers used in this study included: hexamethylene diisocyanate (HMDI), poly(ethylene glycol) diglycidyl ether (epoxy), glutaraldehyde (GTA), and genipin. The prepared porous structures were analyzed using Fourier Transform Infrared Spectroscopy (FT-IR), thermal and mechanical analysis as well as water absorption analysis. The microstructures of the prepared samples were analyzed using Scanning Electron Microscopy (SEM). The effects of the crosslinking agents were studied on the cytotoxicity of the porous structure indirectly using MTT analysis. The affinity of L929 mouse fibroblast cells for attachment on the scaffold surfaces was investigated by direct cell seeding and DAPI-staining technique. It was shown that while all of the studied crosslinking agents were capable of stabilizing prepared gelatin scaffolds, there are noticeable differences among physical and mechanical properties of samples based on the crosslinker type. Epoxy-crosslinked scaffolds showed a higher capacity for water absorption and more uniform microstructures than the rest of crosslinked samples, whereas genipin and GTA-crosslinked scaffolds demonstrated higher mechanical strength. Cytotoxicity analysis showed the superior biocompatibility of the naturally occurring genipin in comparison with other synthetic crosslinking agents, in particular relative to GTA-crosslinked samples.

The current study presents an effective and simple strategy to obtain stable porous scaffolds from gelatin via gas foaming method. The technique exploits the intrinsic foaming ability of gelatin in the presence of CO2 to obtain a porous structure stabilised with glutaraldehyde. The produced scaffolds were characterised using physical and mechanical characterisation methods. The results showed that gas foaming may allow the tailoring of the 3-dimensional structure of the scaffolds with an interconnected porous structure. To assess the effectiveness of preparation method in mitigating the potential cytotoxicity risk of using glutaraldehyde as a crosslinker, direct and indirect cytotoxicity assays were performed at different concentrations of glutaraldehyde. The results indicate the potential of the gas foaming method, in the preparation of viable tissue engineering scaffolds.

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In the context of gross anatomy education, novel augmented reality (AR) systems have the potential to serve as complementary pedagogical tools and facilitate interactive, studentcentered learning. However, there is a lack of AR systems that enable multiple students to engage in collaborative, team-based learning environments. This article presents the results of a pilot study in which first-year medical students (n = 16) had the opportunity to work with such a collaborative AR system during a full-day gross anatomy seminar. Student performance in an anatomy knowledge test, conducted after an extensive group learning session, increased significantly compared to a pre-test in both the experimental group working with the collaborative AR system (P < 0.01) and in the control group working with traditional anatomy atlases and three-dimensional (3D) models (P < 0.01). However, no significant differences were found between the test results of both groups. While the experienced mental effort during the collaborative learning session was considered rather high (5.13 ± 2.45 on a seven-point Likert scale), both qualitative and quantitative feedback during a survey as well as the results of a System Usability Scale (SUS) questionnaire (80.00 ± 13.90) outlined the potential of the collaborative AR system for increasing students' 3D understanding of topographic anatomy and its advantages over comparable AR systems for single-user experiences. Overall, these outcomes show that collaborative AR systems such as the one evaluated within this work stimulate interactive, student-centered learning in teams and have the potential to become an integral part of a modern, multimodal anatomy curriculum. Anat Sci Educ 14: 590-604.

mRNA stability is modulated by elements in the mRNA transcript and their cognate RNA binding proteins. Poly(U) binding protein 1 (Pub1) is a cytoplasmic Saccharomyces cerevisiae mRNA binding protein that stabilizes transcripts containing AU-rich elements (AREs) or stabilizer elements (STEs). In a yeast two-hybrid screen, we identified nuclear poly(A) binding protein 2 (Nab2) as being a Pub1-interacting protein. Nab2 is an essential nucleocytoplasmic shuttling mRNA binding protein that regulates poly(A) tail length and mRNA export. The interaction between Pub1 and Nab2 was confirmed by copurification and in vitro binding assays. The interaction is mediated by the Nab2 zinc finger domain. Analysis of the functional link between these proteins reveals that Nab2, like Pub1, can modulate the stability of specific mRNA transcripts. The half-life of the RPS16B transcript, an ARE-like sequence-containing Pub1 target, is decreased in both nab2-1 and nab2-67 mutants. In contrast, GCN4, an STE-containing Pub1 target, is not affected. Similar results were obtained for other ARE-and STE-containing Pub1 target transcripts. Further analysis reveals that the ARE-like sequence is necessary for Nab2-mediated transcript stabilization. These results suggest that Nab2 functions together with Pub1 to modulate mRNA stability and strengthen a model where nuclear events are coupled to the control of mRNA turnover in the cytoplasm.