Extended Data Fig. 1: High throughput fabrication of micro-liter disks.
From: Instant assembly of collagen for tissue engineering and bioprinting
(a) Video recording showing high-throughput micro-liter collagen disk fabrication. Red boxes mark the same location where a 5 μL collagen droplet was deposited at t = 0. Scale bar, 2 mm. (b) Reflectance confocal microscopy reveals pore sizes from the surface to a 49 μm depth of collagen gels assembled via MMC vs. regular conditions (n = 42509, 35998, 18880, 15958, and 14807 pore measurements for five Z-sections of N = 1 crowded gel; n = 2134, 2291, 2158, 2156, 2260 pore measurements for five Z-sections of N = 1 regular gel). Dotted lines in the plots indicate the pore size of 2 μm. Scale bars, 10 μm. Box plot whiskers, boxes, and lines represent minimum, maximum, 25th–75th percentiles, and median. Comparisons were determined by one way ANOVA with a Tukey’s test. (c) Disk area versus collagen precursor droplet volume shows robust, tunable fabrication, with a linear regression passing through the origin. Data represent independent droplets from two independent experiments. (d) Confocal images showing the fluorescent intensity of crowded disks and regularly gelled collagen domes made of GFP-labeled collagen with varied collagen concentration. Scale bar: 500 μm. The fluorescent intensity measurements of the gels normalized against the mean intensity of the 2 mg/mL regular collagen gels. (For the crowding method, n = 22, 18, 21, 19, and 29 disks for 2, 4, 6, 8, and 10 mg/mL concentrations respectively; for the regular method, n = 14, 17, 20, and 17 disks for 2, 4, 6, and 8 mg/mL concentrations respectively. Disks were pooled from two independent replicates.) Data are presented as mean ± s.d. Comparisons were determined by two-way ANOVA with a Tukey’s test. P values indicate the significance of the comparisons between methods for the same collagen concentrations. Comparisons between other conditions are listed in the source data. (e) Collagen microparticle fabrication via pressurized spraying into the MMC bath. The fluorescent images show the 3D morphology of collagen microparticles fabricated with acidic 10 mg/mL collagen solution. Scale bars, 50 μm (left); 10 μm (right).
