Figure 8.
3D interaction of various types of cells with incorporated hydrogel. (a) Cells are seeded onto hydrogel, and then migrate in individually. (top) Migration of mouse smooth muscle precursor cells (10T 1/2) into type 1 collagen (2.0 mg/ml, initial pH 9.0), on day 6 co-cultured with hMVECs (right channel). (center) Sheet like migration of mouse breast cancer cells (MTLn3) into type 1 collagen (2.0 mg/ml, initial pH 7.4) in day 3 co-cultured with hMVECs (right channel). (bottom) Migration of human breast cancer cells (MDA-MB-231) into type 1 collagen (2.0 mg/ml, initial pH 7.4) on day 3 under 5 % FBS gradient. (b) Cells formed 3D tissue-like structures on hydrogel. (top) Axonal growth into type 1 collagen (1.0 mg/ml, initial pH 7.4) from primary mouse cortical neurons cultured 2 days under 50 μM Forskolin gradient. (center) Primary hepatocyte cultured on type 1 collagen (2.0 mg/ml, initial pH 7.4) in 7 days under interstitial flow condition. Cells were fixed at day 7 and stained for actin filaments (rhodamine-phalloidin; red), nuclei (DAPI; blue) and SEC fraction (GFP; green). Tight tissue-like hepatocyte structure can be found, without migration. (bottom) Human breast cancer cells (MCF-7) cultured on type 1 collagen (2.0 mg/ml, initial pH 9.0) for 3 days under 5 % FBS gradient formed tight tumor colony without migration. (c) Endothelial cells form intact monolayer on hydrogel, showing capillary morphogenesis into hydrogel. hMVEC cells form complex capillary structure in type 1 collagen (2.0 mg/ml, initial pH 7.4) for 5 days under VEGF gradient and ANG-1 supplement. (d) Floating cells in the media migrate into hydrogel under chemoattractant gradient. T lymphocyte cells (Jurkat) migrating into type 1 collagen (2.0 mg/ml, initial pH 7.4) on day 3 under SDF-1 gradient. (e) Co-culture of neutrophil (HL60) in microfluidic channel covered by hMVEC monolayer cultured 3 days. HL60 migrated through the nMVEC monolayer and then into type 1 collagen (2.0 mg/ml, initial pH 10). Cells were fixed at day 4 and stained for actin filaments (rhodaminephalloidin; red), nuclei (DAPI; blue) and neutrophil (CFDA-SE cell tracker; green). In all other figures not mentioned, actin filaments and nuclei were stained with rhodamine-phalloidin (yellow) and DAPI (blue), respectively. White lines indicate outline of incorporated hydrogel. Scale bars indicate 100 μm.