Preservation of Complex Multiphase Architectures in Polymer-Based Artificial Cells by Photo-Crosslinking.

Nature utilizes phase separation to create biomolecular condensates which spatially organize cellular components. In artificial cells, however, mimicking the structure of cellular multiphase systems is challenging. While transient or dynamically induced structures can be created, their lifetime is often very limited. Here, a strategy is presented for stabilizing these structures via photo-crosslinking. Specifically, methacrylate groups are incorporated in one of the scaffold polymers of this coacervate-based artificial cell. UV light is applied directly after the formation of the transient structure, allowing for dynamic formation but at the same time extending the structure's lifetime by at least 5-10 times. Interestingly, this strategy is effective on single and multiphase condensates. Additionally, spatio-temporal control over irradiation can create samples in which condensates and parts of condensates have different structures, achieving programmable asymmetry which is rarely observed in artificial systems. It is expected that creating long-lived intricately structured condensates will contribute to performing increasingly complex functions and develop more advanced artificial cells.