Membranized Coacervate Microdroplets: from Versatile Protocell Models to Cytomimetic Materials

Area of Science:

• Biomimetic materials science
• Protocell engineering
• Soft matter physics

Background:

• Complex coacervate microdroplets are promising for bottom-up protocell construction but lack membranes, limiting sophistication.
• Existing membraneless coacervates hinder the development of advanced artificial cells and cytomimetic materials.

Approach:

• Review of chemical strategies for membranizing preformed coacervate microdroplets.
• Classification of membrane assembly into interfacial self-assembly and droplet-to-vesicle reconfiguration.
• Utilizing diverse surface-active building blocks and assembly processes for membrane formation.

Key Points:

• Coacervate/water interface properties (ultralow tension, broad width) are critical for membranization design.
• Interfacial self-assembly uses amphiphiles or nanoparticles; reconfiguration involves agents or self-membranization.
• Membranized protocells show tunable permeability, metabolic-like reactivity, and signaling.

Conclusions:

• Membranized coacervates enable functional prototissues (e.g., nitric oxide generation) and therapeutic agents (e.g., vasoactive protocells).
• Artificial endocytosis achieved via nanoparticle-caged protocells responding to stimuli or enzymes.
• Highlights limitations and future directions for designing and programming membranized coacervate microdroplets.