Journal: Nature Communications

Article Title: Molecularly cleavable bioinks facilitate high-performance digital light processing-based bioprinting of functional volumetric soft tissues

doi: 10.1038/s41467-022-31002-2

Figure Lengend Snippet: a Schematic of the DLP-based 3D bioprinting with conventional, pure GelMA bioinks, where bioprinting would fail because of the insufficient mechanical properties when the bioinks are used at low concentrations. b Schematic of the DLP-based 3D bioprinting showing high-fidelity fabrication using the GelMA bioinks homogeneously mixed with HAMA. c Enzymatic digestion procedure of the GelMA/HAMA-bioprinted constructs with elevated Hase concentration and treatment duration, enabling increased cleavage of HA, reducing matrix stiffness, and promoting cell spreading and functions. d Tissue-mimics bioprinted with the GelMA/HAMA bioinks could be obtained by precisely controlling the post-bioprinting digestion of the HAMA component to achieve target tissue-matching mechanical properties across a wide range.

Article Snippet: Custom software was developed in MATLAB (v2020, MathWorks, USA) to control the DLP bioprinting processes.

Techniques: Construct, Concentration Assay

Journal: Nature Communications

Article Title: Molecularly cleavable bioinks facilitate high-performance digital light processing-based bioprinting of functional volumetric soft tissues

doi: 10.1038/s41467-022-31002-2

Figure Lengend Snippet: a Timeline of 3D bioprinting of SNaPs and their subsequent culture protocols. The bioink was GelMA/HAMA (2.5%/1.5%), followed by 500 or 1000 U mL −1 of Hase digestion for 24 h post-bioprinting. b Fluorescence micrographs of SNaPs cultured in GM and GH constructs without or with Hase digestion (500 or 1000 U mL −1 , 24 h), stained for NESTIN (red), Ki67 (green), and nuclei counterstaining (blue) at days 1, 2, and 3 after digestion. c Corresponding quantitative analyses of the percentages of Ki67 + nuclei in the four groups. d Quantitative analyses of the percentages of live/dead cells obtained from live/dead staining images. e Gene expression clusters for SNaPs after 4 weeks of differentiation (31 days after digestion) in GM and Hase-1000 digested constructs. f PCA of gene expression values derived from whole-transcriptome sequencing data for SNaPs after 4 weeks of differentiation in GM and Hase-1000 digested constructs. g Total gene numbers of upregulation and downregulation for SNaPs after 4 weeks of differentiation in GM and Hase-1000 digested constructs. h Volcano plot of transcriptional landscape comparing SNaPs after 4 weeks of differentiation in GM and Hase-1000 digested constructs. i K-means clusters of genes of the KEGG enrichment analyses for SNaPs after 4 weeks of differentiation in GM and Hase-1000 digested constructs. b and c , and d n = 3; one-way ANOVA; * p < 0.05, ** p < 0.01(compared with the group of GM), # p < 0.05, ## p < 0.01, ### p < 0.001 (compared with the corresponding results of day 1 in the same group). Data are presented as mean values ± SDs. GM indicates the hydrogel made of 10% GelMA. GH is composed of GelMA/HAMA (2.5%/1.5% for brain-like tissue), and Hase-500 and Hase-1000 are the groups of GelMA/HAMA treated with Hase (500 and 1000 U mL −1 , respectively) for 24 h. Source data are provided as a Source Data file.

Article Snippet: Custom software was developed in MATLAB (v2020, MathWorks, USA) to control the DLP bioprinting processes.

Techniques: Fluorescence, Cell Culture, Construct, Staining, Gene Expression, Derivative Assay, Sequencing

Journal: Nature Communications

Article Title: Molecularly cleavable bioinks facilitate high-performance digital light processing-based bioprinting of functional volumetric soft tissues

doi: 10.1038/s41467-022-31002-2

Figure Lengend Snippet: a , b Confocal fluorescence micrographs showing immunostaining results of ( a ) protein markers representing neurons (SNaPs, green), astrocytes (GFAP, magenta), and neural progenitor cells (NESTIN, red) after 4 weeks of differentiation; and b neuronal markers including neurites (TUJ1, green) and synaptic vesicle proteins (synaptophysin, red). In all cases, the bioink was GelMA/HAMA (2.5%/1.5%), followed by 1000 U mL −1 of Hase digestion for 24 h post-bioprinting. c Optical image showing the 4-week differentiated mini-brain placed on top of the MEA, with maintenance of the overall bioprinted brain shape similar to that shown in Fig. . d High-magnification fluorescence micrographs showing SNaPs after 4 weeks of differentiation directly in contact with the MEA surface and representative heatmaps of active electrodes. e Electrophysiological properties of SNaP-derived neurons in the bioprinted mini-brains with 10% GelMA and GelMA/HAMA (2.5%/1.5%), followed by 1000 U mL −1 of Hase digestion for 24 h post-bioprinting at 1–4 weeks after differentiation: the percentages of active MEA electrode plateaus; the mean firing rates; the numbers of bursts; and the network burst frequencies. n = 4; one-way ANOVA; * p < 0.05, ** p < 0.01, *** p < 0.001 (compared with the group of GM). Data are presented as mean values ± SDs. f , g Electrophysiological property changes of SNaP-derived neurons in the bioprinted mini-brains post-enzymatic digestion, without or with treatment of ( f ) AMPA receptor-antagonist NBQX (10 µM) or ( g ) NMDA receptor-antagonist D-APV (50 µM) at 4 weeks after culturing in the MEA plates. n = 4; two-tailed student’s t -test; * p < 0.05, ** p < 0.01, *** p < 0.001 (compared with the group of DMSO). Data are presented as mean values ± SDs. GM indicates the hydrogel made of 10% GelMA. Hase-1000 indicates the groups of GelMA/HAMA treated with Hase (1000 U mL −1 ) for 24 h. Source data are provided as a Source Data file.

Article Snippet: Custom software was developed in MATLAB (v2020, MathWorks, USA) to control the DLP bioprinting processes.

Techniques: Fluorescence, Immunostaining, Derivative Assay, Two Tailed Test