New method produces uniform self-assembly

A new method for producing uniform, self-assembled nanocells has been developed by researchers at the US National Institute of Standards and Technology (NIST). The method, for which a patent application has been filed, may have applications as an improved technique for encapsulating drug therapies.

Current bulk methods for producing nanocells called liposomes – a type of artificial cell – produce particles in a wide range of sizes. The sizes must be sorted and filtered before being used for drug delivery, since dosage depends critically on size.

The new NIST method uses micrometer-size channels etched into a device to produce self-assembled liposomes of specific sizes from as large as about 240 nanometers (nm) to as small as 100 nm.

A stream of natural fats (lipids) dissolved in alcohol is directed at an intersection of two channels. A water-based liquid containing medicines or other substances is sent toward the lipid stream from two opposing directions. Rather than mixing with the water, the lipids surround it, forming self-assembled nanocells.

Controlling flow rates in the microchannels is said to produce nanocells of specific sizes. Faster flows produce smaller cells. Medicine-filled liposomes made in nanosizes should allow for more accurate drug delivery. In particular, liposomes have been studied for years as a way to concentrate the effectiveness of cancer chemotherapy while minimising harmful side effects.