Electrohydrodynamic atomization: A two-decade effort to produce and process micro-/nanoparticulate materials

Abstract

Electrohydrodynamic atomization (EHDA), also called electrospray technique, has been studied for more than one century. However, since 1990s it has begun to be used to produce and process micro-/nanostructured materials. Owing to the simplicity and flexibility in EHDA experimental setup, it has been successfully employed to generate particulate materials with controllable compositions, structures, sizes, morphologies, and shapes. EHDA has also been used to deposit micro- and nanoparticulate materials on surfaces in a well-controlled manner. All these attributes make EHDA a fascinating tool for preparing and assembling a wide range of micro- and nanostructured materials which have been exploited for use in pharmaceutics, food, and healthcare to name a few. Our goal is to review this field, which allows scientists and engineers to learn about the EHDA technique and how it might be used to create, process, and assemble micro-/nanoparticulate materials with unique and intriguing properties. We begin with a brief introduction to the mechanism and setup of EHDA technique. We then discuss issues critical to successful application of EHDA technique, including control of composition, size, shape, morphology, structure of particulate materials and their assembly. We also illustrate a few of the many potential applications of particulate materials, especially in the area of drug delivery and regenerative medicine. Next, we review the simulation and modeling of Taylor cone-jet formation for a single and co-axial nozzle. The mathematical modeling of particle transport and deposition is presented to provide a deeper understanding of the effective parameters in the preparation, collection and pattering processes. We conclude this article with a discussion on perspectives and future possibilities in this field.

Electrospray Method: Processing Parameters Influence on Morphology and Size of PCL Particles

“…The degradation of PLGA and PLA is faster than PCL since they have more ester groups in their structure than PCL. Therefore, PLGA and PLA particles were suitable for shorter time drug delivery while PCL particles were effective for longer time system due to the slow degradation of PCL [12,13]. This research investigated the effects of electrosprayed processing parameters such as flow rate, the applied voltage and the collecting distance on the morphology and size of PCL microparticles.…”

Sharpening nature's tools for efficient tuberculosis control: A review of the potential role and development of host-directed therapies and strategies for targeted respiratory delivery

“…This modification along with the production of monodisperse batches leading to less product yield being lost to filters, again like spray drying, is especially important when expensive cargos are used [251]. Lastly, electro spraying can be readily scaled-up by increasing the number of nozzles whereas scale-up is a key restraint of a number of the conventional methods mentioned above, particularly solvent evaporation [249].…”

“…Biological polymers, such as chitosan and alginate, and biologically compatible polymers, such as PCL, PLA, PLGA, coupled with variations in the setup, operation parameters, concentration and polymer chain entanglements can produce particles with a range of different morphologies. These include various shapes of single particles, coated particles, multiple particle layers, nanoparticle encapsulated inside micro particles and multi-compartment with a focus towards the development of multifunctional particles capable of targeted drug delivery [249]. Electrohydrodynamic methods provide a gentler approach than some previously described processes that require high temperatures, such as spray drying, therefore maintaining the integrity and bioactivity of sensitive cargos such as proteins and vitamins [250].…”

Taylor Cone–jet Mode in the Fabrication of Electrosprayed Microspheres

“…Besides, electrospray possesses more advantages to produce drug loaded polymeric microparticles compared to other methods such as emulsion, precipitation and spray drying [1]. In more details, some advantages of electrospray method are the high permeability to small drug molecules, the high drug loading capacity and encapsulation efficiency, the simple one-step process and the controlled ability of drug release through ester linkage degradation.…”