Droplet-Based Microfluidics as a Platform to Design Food-Grade Delivery Systems Based on the Entrapped Compound Type

Abstract

Microfluidic technology has emerged as a powerful tool for several applications, including chemistry, physics, biology, and engineering. Due to the laminar regime, droplet-based microfluidics enable the development of diverse delivery systems based on food-grade emulsions, such as multiple emulsions, microgels, microcapsules, solid lipid microparticles, and giant liposomes. Additionally, by precisely manipulating fluids on the low-energy-demand micrometer scale, it becomes possible to control the size, shape, and dispersity of generated droplets, which makes microfluidic emulsification an excellent approach for tailoring delivery system properties based on the nature of the entrapped compounds. Thus, this review points out the most current advances in droplet-based microfluidic processes, which successfully use food-grade emulsions to develop simple and complex delivery systems. In this context, we summarized the principles of droplet-based microfluidics, introducing the most common microdevice geometries, the materials used in the manufacture, and the forces involved in the different droplet-generation processes into the microchannels. Subsequently, the encapsulated compound type, classified as lipophilic or hydrophilic functional compounds, was used as a starting point to present current advances in delivery systems using food-grade emulsions and their assembly using microfluidic technologies. Finally, we discuss the limitations and perspectives of scale-up in droplet-based microfluidic approaches, including the challenges that have limited the transition of microfluidic processes from the lab-scale to the industrial-scale.

Flexible Toolbox of High-Precision Microfluidic Modules for Versatile Droplet-Based Applications

“…The TFP offers flexibility with tubes of varying diameters, increasing the range of possible droplet diameters and volumes that can be achieved [28]. The TFP is faster to produce and easily adaptable, as no new constructions are needed for droplet volume adaptation, as described in flow-focusing solutions using chips [47,48]. The TFP-based droplet generation, as depicted in Figure 3, aligns with numerical studies on chip-based droplet generators, where the droplet volume increases with decreasing flow rate ratios from the continuous to the disperse phase ( .…”

Preparation and Regulation of Natural Amphiphilic Zein Nanoparticles by Microfluidic Technology

“…With the rapid development of nanotechnology, microfluidic technology, as a precision and efficient micro and nano scale processing method, has shown unique advantages in the design and preparation of nanomaterials [ 1 , 2 , 3 , 4 ]. By precisely manipulating the fluid flow, mixing and reaction conditions in microfluidic channels at the micron to nanometer level, microfluidic technology achieves a high degree of control over the morphology, size, surface properties and other microscopic characteristics of nanoparticles, which greatly promotes the wide application of functional nanoparticles in biomedicine, catalysis, sensing and environmental remediation [ 5 , 6 , 7 , 8 ].…”

“…It has been shown that using the microfluidic system, researchers can precisely control the mixing process of zein ethanol soluble solution with anti-solvent or other additives and effectively prepare zein nanoparticles with uniform particle size and good stability through rapid diffusion and solidification at the micro scale [ 8 ]. Against this background, microfluidic technology provides a new strategy to solve the above problems.…”