Sheer velocity dating in the dark
Historically, significant effort has focused on strategies for effective DNA and RNA delivery; however, the predominant methods for in vivo (viral) and in vitro (liposomal) transfection are not well-suited to delivery of proteins, small molecules, quantum dots and other nanoparticles of interest in emerging clinical and laboratory applications (e.g., cell reprogramming).
Many small lipophilic molecules spontaneously cross biological membranes.
Delivery of large and structurally complex target molecules into cells is vital to the emerging areas of cellular modification and molecular therapy.
Inadequacy of prevailing in vivo (viral) and in vitro (liposomal) gene transfer methods for delivery of proteins and a growing diversity of synthetic nanomaterials has encouraged development of alternative physical approaches.
An array of micromachined nozzles focuses ultrasonic pressure waves, creating a high-shear environment that promotes transient pore formation in membranes of transmitted cells.
Acoustic Shear Poration (ASP) allows passive cytoplasmic delivery of small to large nongene macromolecules into established and primary cells at greater than 75% efficiency.
Efficacy of injury/diffusion-based delivery via shear mechanoporation is largely insensitive to cell type and target molecule; however, enhanced flexibility is typically accompanied by reduced gene transfer effectiveness.
We detail a method to improve transfection efficiency through coordinated mechanical disruption of the cell membrane and electrophoretic insertion of DNA to the cell interior.
Field-mediated membrane poration has supplanted chemical methods in many delivery applications, particularly those involving nongene target molecules and primary cells.
Converging nozzle-like channels were used to achieve DNA transfection via focused acoustic pressure driven cell mechanoporation. have demonstrated the insensitivity of these methods to cell type and target molecule, providing additional evidence to support their potential as a universal route to in vitro and ex vivo delivery.
Efficiency of these methods is comparable to microinjection due to single-cell scale treatment; however, parallel arrays of flow constrictions in microchannels (2D) or orifice plates (3D) yield much higher throughput.
This is not true of larger macromolecules, which require alternative means to enter the cell interior.
Ideal delivery systems also protect materials from cytoplasmic degradation, convey materials to a target location, and facilitate action on that target.