Controlled Synthesis of 3D Multi‐Compartmental Particles with Centrifuge‐Based Microdroplet Formation from a Multi‐Barrelled Capillary

Abstract

Controlled synthesis of micro multi-compartmental particles using a centrifuge droplet shooting device (CDSD) is reported. Sodium alginate solutions introduced in a multi-barreled capillary form droplets at the capillary orifice under ultrahigh gravity and gelify in a CaCl(2) solution. The size, shape, and compartmentalization of the particles are controlled. Co-encapsulation of Jurkat cells and magnetic colloids into Janus particles is demonstrated. The Janus particles present sensitive reaction toward magnetic fields, while the viability of the encapsulated cells is 91%.

Observation and Manipulation of a Capillary Jet in a Centrifuge-Based Droplet Shooting Device

“…Thus, in the range of Bo addressed in the present study, if surface tension and density are the same, a liquid jet of fluid with higher viscosity would tend to approach the dripping regime, compared to that of less viscous fluid released from a capillary orifice of the same diameter. As we previously reported in the dripping regime, we have the correlation d p 9 d c 1/3 [9]. Therefore, introduction of a capillary with a thin orifice and a high centrifugal gravity that produces the jetting regime could miniaturize particles more than that of the dripping regime.…”

“…The particles obtained by the jetting regime in the present study is relatively polydispersed (coefficient of variation (CV): 15.0% for those in Figure 4a), compared to those obtained by the dripping regime in the CDSD (CV: 2.0% [1]). This polydispersity could be due to the unsteady fluid dynamic process of the droplet formation in the jetting regime, in contrast to the that of the dripping regime; the instability of the capillary jet that causes droplet formation in the jetting regime should be largely fluctuated by external disturbances, such as the subtle mechanical vibration of the centrifuge, whereas in the dripping regime droplet size can be determined by a quasi-steady balance between the surface tension and the gravitational force acting on the pendant drop at the capillary orifice [9]. Since other devices utilizing hydrodynamic instability to produce particles, including T-junction and flow-focusing, produce monodispersed particles [8,20], we could enhance the uniformity of the particle size obtained the jetting regime in the CDSD by improving the precision of the device setup to suppress the disturbances.…”

“…Recently, we have reported a centrifuge-based droplet shooting device (CDSD), a capillary-based fluidic device for the synthesis of microparticles in a centrifugal tube [9]. In the CDSD, the flow of a sodium alginate solution is ejected from a glass capillary nozzle by centrifugal gravity and forms droplets.…”

Microfluidic generation of Buddha beads-like microcarriers for cell culture

“…Among them, microcarriers have emerged as novel biomimetic platforms, which offer 3D biomaterial scaffolds for cell encapsulation and aggregate formation [10][11][12][13][14][15]. Several approaches have been proposed for fabricating microcarriers, such as photolithography, micromolding, electrojetting and microfluidics [16][17][18][19][20][21][22][23][24]. In comparison with other approaches, microfluidic microcarriers are a promising technique for cell encapsulation because of their advantages of excellent monodispersity, precise size control, high throughput, and better microenvironmental control [21][22][23][24][25][26][27][28].…”

Microfluidic production of single micrometer-sized hydrogel beads utilizing droplet dissolution in a polar solvent

“…However, there exist very few techniques for preparing monodisperse hydrogel beads with sizes as small as single mammalian cells ($10 lm). 12,[25][26][27] One of the reasons can be attributed to the difficulty in generating small droplets of viscous precursor solutions using microfabricated nozzles or microfluidic channels. In addition, controlling the morphologies of such small hydrogel beads so as to obtain non-spherical beads remains a challenge.…”