A Microfluidic System of Gene Transfer by Ultrasound

Abstract

Ultrasonic gene transfer has advantages beyond other cell transfer techniques because ultrasound does not directly act on cells, but rather pushes the gene fragments around the cells into cells through an acoustic hole effect. Most examples reported were carried out in macro volumes with conventional ultrasonic equipment. In the present study, a MEMS focused ultrasonic transducer based on piezoelectric thin film with flexible substrate was integrated with microchannels to form a microfluidic system of gene transfer. The core part of the system is a bowl-shaped curved piezoelectric film structure that functions to focus ultrasonic waves automatically. Therefore, the low input voltage and power can obtain the sound pressure exceeding the cavitation threshold in the local area of the microchannel in order to reduce the damage to cells. The feasibility of the system is demonstrated by finite element simulation and an integrated system of MEMS ultrasonic devices and microchannels are developed to successfully carry out the ultrasonic gene transfection experiments for HeLa cells. The results show that having more ultrasonic transducers leads a higher transfection rate. The system is of great significance to the development of single-cell biochip platforms for early cancer diagnosis and assessment of cancer treatment.

Activation and Switching of Supramolecular Chemical Signals in Multi-Output Microfluidic Devices

“…Convection-diffusion reaction equations for reacting polyelectrolyte-surfactant flows were solved using Matlab 2021a software with Partial Differential Equations Toolbox. Diffusion coefficients of SDS ions were obtained from [ 48 ]. For simulations, the value of the polyelectrolyte-surfactant association rate constant was set to 10 4 L·mol −1 ·s −1 .…”

“…It is a potent strategy for on-demand generation of various supramolecular chemical signals in microchips. In addition, the application focus of microfluidic soft matter systems is biomedicine [ 20 , 38 , 41 , 45 , 46 , 47 , 48 ] that matches the application trends of microfluidic chemical signal and logic gate circuits.…”

Tuning Properties of Polyelectrolyte-Surfactant Associates in Two-Phase Microfluidic Flows

“…Microfluidics provides new options by which to control synthesis [15,16] and properties [17,18] of polyelectrolyte-surfactant complexes, as compared with macroscopic conditions. Microfluidic confinement in the range of dozens or hundreds of micrometers creates a non-equilibrium environment inside microchannels [19], which allows bottom-up engineering of soft matter in ordered diffusion-controlled reactive flows [20][21][22][23] or emulsion droplets [24][25][26]. Microfluidic synthesis produces nanoparticles with a broader size range and less dispersity than in macroscopic conditions [18,21,23,26].…”

“…Microfluidic synthesis produces nanoparticles with a broader size range and less dispersity than in macroscopic conditions [18,21,23,26]. Microfluidic devices expand synthesis and application horizons of functional polyelectrolyte systems, especially for diagnostics [27,28] and drug delivery medicine [22,25,29].…”