Separation of Different Sized Nanoparticles with Time Using a Rotational Flow

Abstract

In this paper, we describe the development of a microfluidic centrifuge with two inlets and two outlets potentially capable of rapidly separating nanoparticles and nanovesicles. Compared with the microfluidic centrifuge with a single inlet and outlet, the 2 ×2 microfluidic centrifuge gives improved centrifugation performance by increasing momentum flux transfer, angular velocity, and centrifugal acceleration. The center of flow rotation and the symmetry of the horizontal velocity in the microchamber were examined numerically. On the basis of the determined maximum velocity, the angular velocity and centrifugal acceleration were also evaluated. The centrifugation time of three different nanoparticles was examined by calculating the time when the nanoparticles left the microchamber for the first time. For visual observation and quantitative measurement of nanoparticle centrifugation, a 2 ×2 microfluidic centrifuge was fabricated and the experimental results demonstrate similar physical behavior to those of a mechanical centrifuge. On the basis of a comparison of the centrifugation time of two different nanoparticle populations of 300 and 700 nm in diameter, we propose that nanoparticles of different sizes can be physically separated by time under a range of inlet volume flow rates.

Label-Free Isolation of Exosomes Using Microfluidic Technologies

“…By contrast, smaller and less dense particles are less deflected toward the outer wall, thereby remaining near the inner wall (Figure 12A). Using a similar strategy, Kwon et al 304 separated 300 and 700 nm particles based on their velocity and centrifugation time. While centrifugal microfluidic technology has been extensively used for manipulation, sorting, and analysis of biological particles like cells, 303,305−307 the potential of this approach for isolation of EVs has rarely been studied.…”

“…308 Despite the advantages of centrifugal microfluidics, it is noted that this method does not offer continuous separation like other microfluidic methods. 301,[303][304][305]307,308 In addition, these platforms are relatively expensive to apply for nanoscale separation, and several challenges remain, including stable operation in the absence of a density gradient, minimizing wall shear effects, and tuning device geometry and retention times in the microchannels. 301,[303][304][305]307,308 CONCLUSION With significant attention being paid to the potential use of exosomes for clinical applications as diagnostic and therapeutic tools, it is important to understand the nature of exosomes versus other EVs.…”

Advancements in microfluidics for nanoparticle separation

“…72,73 However, it is difficult to choose a suitable gradient chemical and it requires a longer preparation time to apply the gradient. 74 Arosio et al developed a density-free centrifugal microfluidic technique that does not rely on wall interactions like sedimentation field flow fractionation, and requires a shorter time than conventional centrifugation to sort nanoparticles without the need for sample dilution. In addition to the centrifugal force and hydrodynamic drag force, a buoyancy force is also present on the nanoparticles.…”

“…75 Another centrifugal microfluidic technique designed by Kwon et al was able to separate nanoparticles based on the difference in the velocity and duration of centrifugation between 300 nm and 700 nm particles using 2 × 2 inlets and outlets. 74,76 However, the requirement of for centrifugation equipment makes centrifugal microfluidics relatively expensive to apply for nanoparticle separation and it cannot perform continuous separation like other microfluidic techniques.…”

Continuous Interfacial Centrifugal Separation and Recovery of Silver Nanoparticles

“…Since the accelerating/decelerating time for centrifuges is significant, scaling up a batch operation results in unwanted downtime. The efforts for continuous‐flow centrifugal separation have been restricted to microfluidics methods . Due to the small radii of curvatures in these setups, the centrifugal forces generated are weak and thus separation is suitable for several hundred nanometers to micrometer‐sized particles.…”