Cytoskeleton-functionalized synthetic cells with life-like mechanical features and regulated membrane dynamicity
The cytoskeleton is a crucial determinant of mammalian cell structure and function, providing mechanical resilience, supporting the cell membrane and orchestrating essential processes such as cell division and motility. Because of its fundamental role in living cells, developing a reconstituted or artificial cytoskeleton is of major interest. Here we present an approach to construct an artificial cytoskeleton that imparts mechanical support and regulates membrane dynamics. Our system involves amylose-based coacervates stabilized by a terpolymer membrane, with a cytoskeleton formed from polydiacetylene fibrils. The fibrils bundle due to interactions with the positively charged amylose derivative, forming micrometre-sized structures mimicking a cytoskeleton. Given the intricate interplay between cellular structure and function, the design and integration of this artificial cytoskeleton represent a crucial advancement, paving the way for the development of artificial cell platforms exhibiting enhanced life-like behaviour.
The cytoskeleton of the mammalian cell is one of its key determining components. It not only provides structural resilience by regulating the cell’s mechanical properties and by supporting the cell membrane but also has an important scaffolding function and plays an essential role in cell division and motility1. Due to its essential role in natural cells, the cytoskeleton has gained increasing interest in the field of artificial cell research. This field of science uses a bottom-up self-assembly approach to construct compartments with cell-like features. This is motivated by the rationale that the development of artificial cells will provide us with a better insight on how biological processes are organized in living cells2,3. The focus of the community has been mainly on functional behaviour, such as communication4,5, compartmentalized biosynthesis and metabolism6,7, adaptation8,9 and motility10,11. Recently, more attention has been paid to the mimicry of structural aspects of living cells. For example, coacervates have garnered renewed interest as materials that mimic the crowdedness of the cell’s cytoplasm, which is intrinsically connected to functional behaviour, as crowdedness will affect diffusivity and interactions between encapsulated biomolecules12. Furthermore, artificial organelles have been developed that have been incorporated in artificial cells to achieve hierarchical control over biological processes13,14. Important advances have been reported with regard to the development of an artificial or reconstituted cytoskeleton15,16,17,18. Examples include the observation of membrane deformations of lipid vesicles using a reconstituted actomyosin ring19, irreversible directional cargo transport along DNA filaments20, the mimicry of actomyosin-based contraction with a composite material based on a temperature-responsive polymer (poly(N-isopropylacrylamide)) and F-actin21 and the restructuring of coacervate droplets via the gelation of actin22. In particular, the role of the cytoskeleton in regulating artificial cellular mechanical features remains an interesting field of research23,24,25.
