Fig. 2: Rheological properties of MAGIC matrices including low stiffness and stress relaxation drive gold-standard morphogenesis.
From: Stress-relaxing granular bioprinting materials enable complex and uniform organoid self-organization
a, At 4 °C, oscillatory amplitude sweeps at 1 Hz reveal that various MAGIC matrix compositions behave as yield-stress materials, indicated by G′ and G″ cross-over. b, MAGIC matrices behave as Herschel–Bulkley fluids at 4 °C with yield-stresses calculated using a power-law model. c, Storage and loss moduli at 1 Hz and 1% strain of MAGIC matrices at 37 °C prepared from 1 wt% or 0.5 wt% AMGs. d, Storage and loss moduli at 1 Hz and 1% strain of MAGIC matrices at 37 °C prepared using different volume ratios of 0.5 wt% AMGs:Matrigel. e, Mouse intestinal organoids grown in pure Matrigel (top row) and MAGIC matrices of several compositions (lower rows) 5 days after seeding. Scale bars, 200 µm. f, Quantification of organoid crypt width as a function of matrix composition. g, Quantification of crypt length as a function of matrix composition. h, Normalized stress-relaxation curves for undiluted 0.5 wt% AMG slurry at 10% strain or Matrigel over 1 h at 1%, 10% or 100% strain. i, Bright-field images and segmented cartoons simulating organoid growth over time in Matrigel. Scale bar, 100 µm. j, Measurement of material strain at the organoid–ECM interface over time quantified using segmented organoid perimeters. The dashed line at 10% strain represents the strain value used for most stress-relaxation measurements. k, Normalized stress-relaxation curves for Matrigel or MAGIC matrices over 1 h at 1% strain. l, Normalized stress-relaxation curves for Matrigel or MAGIC matrices over 10 s at 10% strain. m, Normalized stress-relaxation curves for Matrigel or MAGIC matrices over 1 h at 10% strain (left) and quantification of average relaxation time for each matrix using a stretched exponential model (right). n, Organoid array bioprinting experiments demonstrating similar impacts on crypt morphogenesis when MAGIC matrix compositions are used as bioprinting support baths. Scale bars, 500 µm. For all rheological experiments, data shown are mean ± s.d. from n = 3 independently prepared replicates. For crypt length and width measurements, data shown are mean ± s.d. on the median n = 15 crypts from ≥10 organoids per matrix condition. For ECM strain during organoid growth, data shown are mean ± s.d. of n = 9 organoids. Statistical significance was determined by one-way ANOVA with Tukey’s multiple comparisons (b,c,m) or Dunnett’s multiple comparison (f,g); values shown for P determined by one-way ANOVA (b) or by multiple comparisons (c,m,f,g) < 0.05; NS, not significant.
