Evaluation of continuous flow nanosphere formation by controlled microfluidic transport

Microfluidics for the Production of Nanomedicines: Considerations for Polymer and Lipid-based Systems

BACKGROUND

Microfluidics is becoming increasingly of interest as a superior technique for the synthesis of nanoparticles, particularly for their use in nanomedicine. In microfluidics, small volumes of liquid reagents are rapidly mixed in a microchannel in a highly controlled manner to form nanoparticles with tunable and reproducible structure that can be tailored for drug delivery. Both polymer and lipid-based nanoparticles are utilized in nanomedicine and both are amenable to preparation by microfluidic approaches.

AIM

Therefore, the purpose of this review is to collect the current state of knowledge on the microfluidic preparation of polymeric and lipid nanoparticles for pharmaceutical applications, including descriptions of the main synthesis modalities. Of special interest are the mechanisms involved in nanoparticle formation and the options for surface functionalisation to enhance cellular interactions.

CONCLUSION

The review will conclude with the identification of key considerations for the production of polymeric and lipid nanoparticles using microfluidic approaches.

Laser-assisted photothermal heating of a plasmonic nanoparticle-suspended droplet in a microchannel

The present article reports the numerical and experimental investigations on the laser-assisted photothermal heating of a nanoliter-sized droplet in a microchannel when plasmonic particles are suspended in the droplet.

reliable Synthesis of Monodisperse Microparticles: Prevention of Oxygen Diffusion and Organic Solvents Using Conformal Polymeric Coating onto Poly(dimethylsiloxane) Micromold

An effective polymeric thin film deposited by initiated chemical vapor deposition (iCVD) process was presented and its application as a barrier film on the PDMS micromold blocking the penetration of oxygen and organic solvents was investigated. With this barrier film, we were able to synthesize monodisperse polymeric particles of sizes down to 3 μm, which has been reported to be extremely challenging with bare PDMS micromold. The polymeric barrier film on the PDMS micromold enabled this successful synthesis of microparticles by effectively blocking the diffusion of oxygen, which is a well-known radical quencher in radical polymerization, through the PDMS micromold. Furthermore, the iCVD barrier film substantially decreased the penetration of various organic solvents such as acetone, tert-butanol, PDMS oil, and decane as well as organic substances including fluorescent molecules like rhodamine B and fluorescein isothiocyanate (FITC). Therefore, the polymeric barrier film coated on PDMS micromold via iCVD process will broaden the application of PDMS to microfluidic area for the synthesis of smaller microparticles with various organic substances.

Analysis of a laminar-flow diffusional mixer for directed self-assembly of liposomes

The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-μm(2) cross-section. Use of the device produces liposomes in the size range of 100-300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein.

The Glass Menagerie: diatoms for novel applications in nanotechnology

Diatoms are unicellular, eukaryotic, photosynthetic algae that are found in aquatic environments. Diatoms have enormous ecological importance on this planet and display a diversity of patterns and structures at the nano- to millimetre scale. Diatom nanotechnology, a new interdisciplinary area, has spawned collaborations in biology, biochemistry, biotechnology, physics, chemistry, material science and engineering. We survey diatom nanotechnology since 2005, emphasizing recent advances in diatom biomineralization, biophotonics, photoluminescence, microfluidics, compustat domestication, multiscale porosity, silica sequestering of proteins, detection of trace gases, controlled drug delivery and computer design. Diatoms might become the first organisms for which the gap in our knowledge of the relationship between genotype and phenotype is closed.