Spontaneous and Driven Growth of Multicellular Lipid Compartments to Millimeter Size from Porous Polymer Structures**

This report describes a method to obtain multicellular shaped compartments made by lipids growing from a sponge-like porous structure. Each compartment is several tens of micrometers in diameter and separated by membranes comprised of phospholipid and amphipathic molecules. The multi-compartment structure spontaneously grew to a millimeter scale, driven by an ionic concentration difference between the interior and exterior environments of the sponge. These compartments can also easily incorporate hydrophilic species as a well as smaller materials such as liposomes. Additionally, we showed that mechanical squeezing of the sponge was also effective in producing multicellular bodies. These simple methods to obtain large-scale multicellular compartment of lipid membrane will help future designs and trials of chemical communications on artificial cells.