Our latest discoveries in soft lithography and microfluidics allow Creative Biolabs to help clients manipulate small volumes of fluids with remarkable reproducibility, opening up new avenues for the fabrication of emulsions and particles with excellent monodispersity and specific structures.
Emulsions are metastable dispersions of one fluid in another immiscible. Classic emulsification procedures produce polydisperse isotropic emulsion droplets that solidify physically or chemically into spherical particles. Recent advances in microfluidics allow the drop-by-drop in-chip generation of highly uniform monodisperse emulsions, whose size can vary from a few hundred nanometers to several micrometers. Two immiscible phases meet in a specific geometry to form dimensionally stable droplets that are ionically or chemically induced to cross-link after formation and collection, resulting in highly uniformly sized particles.
Fig 1. Microfluidic platform greatly expands the potential of emulsion polymerization. (Kim, et al. 2013)
Through the emulsion polymerization chip development services Creative Biolabs provides, you can customize the structure of the emulsion generation chip, combined with precise flow rate control, allowing you to achieve deep tunability of microgel particle size, shape, compartment distribution, monodispersity and microstructure. Controllability over such aspects allows you to design emulsified particles with advanced functionality on demand.
Two nozzle configurations are mainly used today, a T-junction by impinging two fluid streams, and a flow-focusing junction that forces a coaxial flow through a small orifice. Basic chips designed using these two junctions can be achieved directly from our chip inventory. By choosing different emulsification schemes and liquid configurations, particles with different characteristics and functions can be stably and rapidly processed in droplet generation chips.
Fig 2. Typical design of microfluidic droplet generation chip. (Engl, et al. 2008)
O/W emulsion droplets formed by hydrophobic precursors and hydrophilic channel walls can solidify into particles composed of hydrophobic materials. During the manufacturing process, the oil droplets are stabilized by surfactants to prevent the emulsion from coalescing. O/W droplets form stable dispersions in water and complete the symptomatic and delivery of lipophilic drugs. O/W microparticles can be used in micromechanical systems, diagnostic analysis, drug delivery or toxic substance adsorption and other fields. Almost all polymers soluble in organic solvents can be used to fabricate O/W microparticles, while biocompatible and biodegradable polymers (e.g., PLGA, PCL, PLA) are widely developed.
Hydrophilic monodisperse microparticles can be fabricated by W/O emulsions containing water-soluble precursors. After the addition of oil-soluble surfactants, W/O emulsions exist stably in microfluidic devices with hydrophobic channels and polymerize to form microgels by physical means. Hydrophilic droplets with good biocompatibility can incorporate additional water-soluble components or organisms for effective encapsulation. Microgels made of chitosan, alginate, and poly(acrylamide) are widely used as artificial extracellular matrices for cell growth for single-cell studies or cell behavior research in confined environments. In addition, water-in-water dispersions with similar biological functions can also be processed by fluidic control of microfluidic chips.
Microfluidic emulsification technology can encapsulate products with complete activity in one step and achieve stable control of the properties of the encapsulated objects, which provides a potential way to manufacture monodisperse double emulsion droplets, and encapsulate droplets of different components in the same drop. Double-emulsion droplets are generated by connecting two joints in succession, with specially shaped joints that cause collisions of the immiscible two phases to form uniformly sized particles. These periodically generated droplets are then guided to the downstream junction, so that the outer phase re-wraps a layer of droplets similar to the inner phase, thus forming a monodisperse and continuous O/W/O or W/O/W emulsion. Droplet size, composition and ratio are directly controlled by changing the flow rate.
Fig 3. Schematic of double emulsification or multiple emulsification. (Naresh, et al. 2022)
With the advancement of microfabrication technology and in-depth knowledge of microfluidics, we have developed units with more functions for our chips. These functions can be realized from basic parallel flow generation, monodisperse droplet generation, emulsion dilution and concentration to more complex alternating sequence generation, droplet fusion, multiphase particles, asymmetric droplet breakup, droplet deformation, etc. By combining these functional units with other chemical processes, the shape, size, compartment distribution, and microstructure of particles can be well manipulated at each step of processing. Our optimized manufacturing approaches are used to synthesize new dispersed materials with complex structures and specific functions, and ultimately help your research on drug delivery, cell carriers, nanocapsules, active pigments, and more.
Fig 4. Production of functionalized gel particles by microfluidic chips. (Naresh, et al., 2022)
Emulsion polymerization is a simple but highly operational process, which also means that more complex chip designs often have more and more specialized functions. In order to take full advantage of the benefits of microfluidic emulsion polymerization chips, Creative Biolabs recommends our one-stop emulsion polymerization chip design services while providing basic droplet generation chips to customers. Our well-trained R&D team will provide a reasonable design for your high-end application or bring your personally optimized design to reality. Whether you want to develop microcarriers for your own drugs/cells, or develop new functional particles, we will be your best partner, so don't hesitate to contact us for more information.
For Research Use Only. Not For Clinical Use.