Journal: Microsystems & Nanoengineering
Article Title: High-fidelity bioassembly of organoids and spheroids using inertial droplet microfluidics for precision oncology and tumor microenvironment modeling
doi: 10.1038/s41378-026-01244-x
Figure Lengend Snippet: OsciSphere operates in a deterministic regime to produce uniform µMCTs that recapitulate key physiological tumor features. a Scaffold-free ULA culture (Day 4) yields a multimodal population, with a single large central spheroid and numerous highly variable satellite aggregates. b Conventional Matrigel dome culture (Day 3) exhibits significant spatial heterogeneity driven by diffusion gradients, with smaller spheroids in the nutrient-poor center and larger ones at the periphery. c OsciSphere-generated µMCTs (~600 cells/droplet, Day 3) exhibit structural isotropy and consistency. d Quantification of spheroid diameters confirms the superior monodispersity of µMCTs ( n = 100, CV = 4.2%) compared to the high variability of ULA ( n = 244) and dome ( n = 237) cultures (mean ± SD, **** p < 0.0001). e Bright-field time-lapse shows rapid self-assembly of compact HCT116 spheroids by Day 1. f Live/Dead staining at 72 h confirms high cell viability. g Histological analysis (H&E) reveals a dense 3D tissue architecture, with immunohistochemistry for Ki67 confirming robust proliferative activity within the spheroid. h Optimization of formation efficiency reveals a critical density threshold at 600–900 cells per microsphere, achieving 99.6% successful formation by Day 2 ( n = 10, mea n ± SD, red star indicates the optimal 600-cell condition). i Immunofluorescence (IF) of 2D HCT116 cultures shows basal expression of Vimentin and N-cadherin. Scale bar, 10 µm. j µMCTs display pronounced, organized expression of mesenchymal markers (Vimentin, N-cadherin), indicative of EMT. Scale bar, 50 µm. k This invasive phenotype is validated by RT-qPCR, showing significant upregulation of key EMT-associated genes ( N-cadherin , Snail , Slug ) and cancer stem cell-associated genes ( Sox2 , Oct4 ) in µMCTs ( n = 3, mea n ± SD, **** p < 0.0001). l µMCTs exhibit a physiologically relevant reduced proliferation rate compared to 2D cultures, mimicking in vivo tumor kinetics ( n = 5, mean ± SEM, **** p < 0.0001). m Flow cytometry analysis reveals elevated intracellular ROS levels in µMCTs (51.2%) versus 2D cultures (30.2%), consistent with the establishment of metabolic gradients and a hypoxic tumor microenvironment. Statistical significance was analyzed by using one-way analysis of variance (ANOVA)
Article Snippet: Growth and morphology were monitored via time-lapse phase-contrast imaging (Incucyte S3, Sartorius, Göttingen, Germany).
Techniques: Diffusion-based Assay, Generated, Staining, Immunohistochemistry, Activity Assay, Immunofluorescence, Expressing, Quantitative RT-PCR, In Vivo, Flow Cytometry