Shaping Giant Membrane Vesicles in 3D‐Printed Protein Hydrogel Cages

Abstract

Giant unilamellar phospholipid vesicles are attractive starting points for constructing minimal living cells from the bottom‐up. Their membranes are compatible with many physiologically functional modules and act as selective barriers, while retaining a high morphological flexibility. However, their spherical shape renders them rather inappropriate to study phenomena that are based on distinct cell shape and polarity, such as cell division. Here, a microscale device based on 3D printed protein hydrogel is introduced to induce pH‐stimulated reversible shape changes in trapped vesicles without compromising their free‐standing membranes. Deformations of spheres to at least twice their aspect ratio, but also toward unusual quadratic or triangular shapes can be accomplished. Mechanical force induced by the cages to phase‐separated membrane vesicles can lead to spontaneous shape deformations, from the recurrent formation of dumbbells with curved necks between domains to full budding of membrane domains as separate vesicles. Moreover, shape‐tunable vesicles are particularly desirable when reconstituting geometry‐sensitive protein networks, such as reaction‐diffusion systems. In particular, vesicle shape changes allow to switch between different modes of self‐organized protein oscillations within, and thus, to influence reaction networks directly by external mechanical cues.

Measuring Gaussian Rigidity Using Curved Substrates

“…3. This recasting again shows that our proposed method is feasible and could be implemented with recent submicrometer 3D printing methods [34,35]. It may also be possible to create an approximation to a catenoid by draping a lipid bilayer over a short pillar with radius r 0 ; the geometry would be approximately catenoidal and our results would be valid up to leading order in the shape.…”

Membrane-coated 3D architectures for bottom-up synthetic biology

“…As more and more photoresins are being developed for 3D printing, materials with improved physical and chemical properties would significantly widen the scope of our biological research. For example, soft materials such as shape-shifting hydrogels 26 and protein-based hydrogels [55][56][57] would allow us to create flexible and deformable structures, potentially enabling us to investigate how cytoskeletal proteins deform membranes. Materials with better optical properties are also crucial.…”

Versatile Phospholipid Assemblies for Functional Synthetic Cells and Artificial Tissues

“…For the former case, the division of GUVs can be induced by cell division proteins (bacterial Min proteins), [ 231 ] protein crowding effect, [ 232 ] mechanical force generated by microfluidic splitter [ 233 ] or the compression of 3D‐printed protein hydrogels, [ 234 ] or the osmotic stimulus. [ 56,202,235 ] Symmetric division can be controlled using a mechanical splitter.…”