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|Author(s):||Catherine T. Lo; Andreas Jahn; Wyatt N. Vreeland; Laurie E. Locascio;|
|Title:||A rapid, low-cost preparation of monodisperse niosomes in a microfluidic platform|
|Published:||June 01, 2010|
|Abstract:||Niosomes are synthetic membrane vesicles made of self-assembled non-ionic surfactants (i.e. amphiphilic organic compounds). They bear the same properties as liposomes, namely having an aqueous interior that is separated from the exterior aqueous environment by a bilayer, allowing them to be used in drug delivery applications. However, bulk production of niosomes is often plagued by the inconsistency of vesicle size, which in term can affect the accuracy of drug dosage. The polydispersity of niosome population is caused by the uncontrolled bulk mixing of two liquid phases typically associated with niosome preparation: the organic phase (containing the non-ionic surfactant) and the aqueous phase. In this study, we utilize the advantages available at microscale to control precisely the fluid flow and mixing of fluids, to produce monodisperse niosomes. A surfactant/alcohol stream was hydrodynamically focused by two streams of phosphate buffered saline, to direct the formation of niosomes in a silicon microfluidic channel. The laminar flow in the microchannel enabled controlled diffusive mixing at the two liquid interfaces, where the surfactant assembled into vesicles. We observed that niosome size was tunable by adjusting the flow rate ratio between the two liquid phases and was also correlated to microchannel dimensions. Compared to conventional bulk methods, our microfluidic method produced smaller niosomes with ~50% narrower size distribution and was also less-time consuming on per batch basis. In line with our low-cost theme, we also fabricated a poly(dimethylsiloxane) device using dry-film resist and microwave bonding (without the need for a cleanroom), and demonstrated successfully that hydrodynamic|
|Pages:||pp. 8559 - 8566|
|Keywords:||hydrodynamic focusing, niosomes, PDMS, dry-film resist, microwave bonding|
|DOI:||http://dx.doi.org/10.1021/la904616s (Note: May link to a non-U.S. Government webpage)|
|PDF version:||Click here to retrieve PDF version of paper (5MB)|