This all-aqueous capsule-synthesis approach offer good opportunities to culture cells in membrane-supported liquid compartments. By mixing cells with the emulsion phase, cell-laden microcapsules with uniform size could be generated by electrospray (Fig. ). Human gallbladder cancer cells (SGC-996) were encapsulated in the hybrid microcapsules with a density of 2.5 × 10 5 cells mL -1 and cultured in the complete H-DMEM for 24 days (Fig. ). It can be observed that cells gradually aggregate into clusters and then grew into tumor spheroids. After culture for 24 days, the cell viability in the capsule was examined by a live/dead assay. Relatively large tumor spheroids with diameters ranging from 200 to 300 μm can be found in capsules, suggesting the good permeability and cytocompatibility of the capsules (Fig. ). As a comparative study, GBC cells were encapsulated in the alginate microparticles. With sufficiently long-time of in-vitro culture, the cell spheroids cultured in microparticles are relatively small, with an average size of less than 150 μm (Fig. ). Cell viability test shows that both capsules and particles have a good cytocompatibility. The low permeability of solid hydrogel, in together with the retarded cell-to-cell contact may explain the differences in cell assembly and size of tumor spheroids. Besides, capsules can physically entrap more cells than alginate particles, attributed to the PEGylated fibril cluster that inhibit protein adsorption and cell adhesion.