PEG hydrogels guide self-assembly of ECs into capillary-like networks. (A) Six cell culture conditions were shown to enable endothelial network formation by ECs using 0.5 mM adhesion peptide or less in each hydrogel. Scale bar: 0.5 mm. (B) Condition A showed significant quantifiable effects of sunitinib treatment on total network area, in the form of a low initial network area and the greatest decrease in network area by sunitinib treatment of the tested culture conditions. *p < 0.05 between DMSO and sunitinib treatments, Sidak's multiple comparisons test. Experimental replicates: A, B: DMSO and sunitinib—8. C, E, F: DMSO and sunitinib—6. D: DMSO—3. D: sunitinib—4. DMSO, dimethyl sulfoxide. Color images are available online.