Colloidal Systems in Microencapsulation Techniques

Colloidal systems in microencapsulation techniques integrate dispersed‐phase particles and interfaces to form protective microenvironments around active cargo. Such techniques harness colloidal particles to stabilise emulsions or assemble into shells, enabling the production of core–shell structures, colloidosomes and multi-layered microcapsules with tunable permeability, mechanical robustness and stimuli-responsive behaviour. Particle-stabilised emulsions, often referred to as Pickering emulsions, serve as templates where colloidal particles adsorb irreversibly at liquid–liquid interfaces, preventing coalescence and guiding capsule formation. Advances in self-assembly, interfacial engineering and microfluidic templating have expanded the design space, allowing precise control over capsule size, shell porosity and functionalisation. These developments have broadened applications across drug delivery, food science, cosmetics, catalysis and environmental remediation by improving cargo protection, controlled release and targeted delivery. Recent trends focus on anisotropic and hierarchical assembly of colloidal building blocks, bioinspired materials such as sporopollenin-based shells, and dual-shell architectures that combine organic and inorganic layers for enhanced barrier properties.

Research from Nature Portfolio

Recent studies have demonstrated the hierarchical assembly of crystalline diblock copolymer micelles into mechanically robust colloidosomes possessing tuneable membrane textures and active growth capabilities. By exploiting crystallisation-driven self-assembly, cylindrical micelles act as anisotropic building blocks, enabling post-assembly epitaxial elongation to produce hair-like outgrowths on capsule surfaces, enhancing functionalisation and cargo loading. Another key development utilises transient double emulsions to achieve designer liquid–liquid interfaces with controlled surface coverage and composition. This approach allows multilayered particulate shells to be assembled on emulsion droplets, even with particles of contrasting adsorption characteristics, offering unprecedented freedom to tailor shell heterogeneity and build composite microcapsules for complex multiphase systems.

Research from all publishers

A novel method introduces intact pollen grains during mechanical emulsification to yield monodisperse Pickering emulsions and “yolk–shell” microcapsules. The robust exine of pollen or sporopollenin exine capsules constitutes a resilient inner shell, while sol–gel interfacial engineering generates a uniform outer silica network, minimising cargo leakage and ensuring high structural integrity. In another advance, epoxy-functional diblock copolymer nanoparticles stabilise sub-micron water-in-oil emulsions which, upon ring-opening crosslinking, form silica-reinforced colloidosomes with adjustable shell thickness, offering long-term stability against Ostwald ripening and tuneable small-molecule release profiles. Additionally, a versatile self-assembly strategy embeds cargo within liquid scaffolds that promote the growth and fusion of satellite particles into porous cages; by controlling fusion parameters, the pore architecture of caged colloids can be tailored for applications in targeted delivery and transmembrane transport studies.

Colloidal Systems in Microencapsulation Techniques publication trend

The graph below shows the total number of articles in colloidal systems in microencapsulation techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Colloidosome: A hollow microcapsule whose shell comprises densely packed colloidal particles stabilising an emulsion template.

Pickering emulsion: An emulsion stabilised by solid particles adsorbed at the interface between two immiscible liquids.

Microencapsulation: The process of enclosing active agents within a coated micro-sized carrier to protect and control release.

Core–shell structure: A capsule design featuring a central core of active material surrounded by one or more protective shell layers.

Ostwald ripening: The thermodynamically driven growth of larger droplets at the expense of smaller ones in an emulsion.

Sporopollenin exine capsule (SEC): A resilient, naturally derived microcapsule shell obtained from pollen grain exine used for bioinspired encapsulation.

References

1. Harnessing the Power of Nature: Monodisperse Pickering Emulsion Droplets and Yolk‐Shell Microcapsules Utilizing Bee Pollen Particles. Advanced Functional Materials (2024).
2. Sub-micron colloidosomes with tuneable cargo release prepared using epoxy-functional diblock copolymer nanoparticles. Journal of Colloid and Interface Science (2024).
3. Caged Colloids. Chemistry of Materials (2023).
4. Higher-order assembly of crystalline cylindrical micelles into membrane-extendable colloidosomes. Nature Communications (2017).
5. Designer liquid-liquid interfaces made from transient double emulsions. Nature Communications (2018).