A failed experiment that was originally looking to improve the production of optical glass fibers could form the basis of a new technique for rapidly and reproducibly generating uniform, nanoscale drug delivery particles. Researchers at CREOL, the University of Central Florida’s College of Optics & Photonics, were attempting to heat and draw (or stretch) glass fibers on a homemade tapering machine when they found that, rather than just continuing to stretch into a thinner diameter (as they'd hoped), the core material broke apart into multiple spheres, akin to a thin stream of water flowing from a faucet breaking into droplets. This is caused by a phenomenon known as Rayleigh instability.
The researchers had, in fact, unwittingly developed a platform that could be adapted to produce highly ordered, multicomponent micro- and nanospheres comprising a central core that contains the active components, surrounded by a more structural cladding that holds the central core in place (the cladding can be dissolved away once the particles have formed). Moreover, the technique can be used to generate particles with diameters of anything ranging from 2 mm down to 20 nm, and as well as being highly scalable, fine-tuning the starting materials and controlling the heating and cooling stages allows the production of different types of nanoparticles, including composite, structured spherical particles such as core-shell particles, two-compartment ‘Janus’ particles, and multisectioned ‘beach ball’ particles.
Lead researcher Soroush Shabahang, Ph.D., and colleagues describe their technique in a recent issue of Nature, in a paper titled “Structured spheres generated by an in-fibre fluid instability.”