Yuhang Fu

Paclitaxel loaded human serum albumin nanoparticles stabilized with intermolecular disulfide bonds

We prepared paclitaxel-loaded disulfide-crosslinked human serum albumin nanoparticles (PTX-HSA-NPs) in a microfluidic platform. The entire process includes four steps, i.e., a pretreatment step to partially reduce albumin, a mixing and co-precipitation step, a reaction step, and a dialysis step. Two important factors dominate the successful preparation of stable PTX-HSA-NPs: one is the choice of the anti-solvent in the co-precipitation step, and the other is the reaction time in the reaction step. We demonstrated that the drug-loaded nanoparticles are stable against dilution by the inter-albumin disulfide bonds, but still have a quick drug release profile in the intracellular-mimicking reduction environment. Through cell studies, we showed that the albumin nanoparticle carriers are safe and characterized the cell toxicity of the paclitaxel-loaded nanoparticles with cell lines of human breast cancer cells (MCF-7).

Theoretical analysis and simulation of obstructed breakup of micro-droplet in T-junction under an asymmetric pressure difference

Asymmetric droplet breakup under a pressure difference at two outlets of a T-junction is investigated theoretically and numerically in this study. An accurate analysis of the evolution of droplet dynamics during the obstructed breakup process has been conducted. Meanwhile, the lattice Boltzmann method based on color gradient model is employed to simulate the system with the verification of the theoretical results. It is demonstrated that the Zou-He boundary setting at each outlet is advantageous for modifying the pressure drop of the two branches of T-junction. The results reveal that asymmetric breakup of the unequally sized droplets follows two steps, namely, the filling stage and the breakup stage. Then a universal parameter is proposed to describe the asymmetric condition of droplet breakup in T-junction, which plays a key role to characterize the temporal evolution of volume ratio and the droplet length of formed smaller droplets.

Ionic liquid-based suzuki coupling reaction: From batch to continuous microflow system

Transformed from heterogeneous to homogeneous state, an ionic liquid (IL)-based Suzuki coupling reaction was successfully implemented in a continuous microflow system. Triethylamine (Et3N) was introduced as the base, and N-methylpyrrolidinone (NMP) was used as the solvent of boronic acid, which brought about the first improvement on the reaction performance. Then, the implementation of this reaction in a continuous microflow system brought about further improvement on the reaction yield and selectivity due to better mixing condition. The combination of IL as the reaction medium and the continuous microflow system as the reactor in this work exhibited great potential for efficient Suzuki coupling reactions.

Modeling mass transfer and reaction of dilute solutes in a ternary phase system by the lattice Boltzmann method

In this work, we propose a general approach for modeling mass transfer and reaction of dilute solute(s) in incompressible three-phase flows by introducing a collision operator in lattice Boltzmann (LB) method. An LB equation was used to simulate the solute dynamics among three different fluids, in which the newly expanded collision operator was used to depict the interface behavior of dilute solute(s). The multiscale analysis showed that the presented model can recover the macroscopic transport equations derived from the Maxwell-Stefan equation for dilute solutes in three-phase systems. Compared with the analytical equation of state of solute and dynamic behavior, these results are proven to constitute a generalized framework to simulate solute distributions in three-phase flows, including compound soluble in one phase, compound adsorbed on single-interface, compound in two phases, and solute soluble in three phases. Moreover, numerical simulations of benchmark cases, such as phase decomposition, multilayered planar interfaces, and liquid lens, were performed to test the stability and efficiency of the model. Finally, the multiphase mass transfer and reaction in Janus droplet transport in a straight microchannel were well reproduced.

Simulation of single-phase reacting flows in micro-channel reactors by Lattice Boltzmann method

Fluid dynamics and mixing characteristics directly influence the progress of complex reactions in micro-channel reactors. When a parallel competing reaction takes place in micro-channels, it is crucial that the time scales of mixing and reaction match with each other to reach a high selectivity. In this work, “Villermaux/Dushmann” reaction is incorporated into the modeling scheme of Lattice Boltzmann method (LBM). Using this novel model, the characteristics of mixing and reaction process are simulated in micro-channels with different geometries. The results illustrate the significant impact of the mixing performance on the reaction selectivity. The established LBM model provides a theoretical approach to understanding the interplay of mixing and reactions in micro-channel reactors, which can be applied as a tool to optimize the design of micro-channel devices.