Nanoparticle Synthesis Process Facilitates Chiral Separations

Researchers at the Institute of Bioengineering and Nanotechnology (IBN, Nanos, Singapore, www.ibn.a-star.edu.sg) have developed a fluorocarbon-mediated synthesis technique to control the size and shape of nanoparticles for use in pharmaceutical synthesis and chiral separation applications.

The particles, called "IBN-1" and IBN-5," are made with a wet-chemical technique that incorporates two types of surfactants: One is used as a pattern to create a mesoporous structure and the other limits the particle growth to the nanometer scale. According to IBN, the technique produces 50-200-nm nanometer particles with tunable pore sizes ranging from 5 to 30 nm. Says Yu Han, IBN research fellow, "No general method for creating porous nanoparticles has been reported prior to this work." Previous attempts to produce nanometer-scale particles with nanometer-sized pores were limited in the type of structure, degree of structural ordering, and range of pore size.

One application for the porous nanoparticles is for the production of pure chiral drugs. Typically, liquid catalysts are used to selectively synthesize the preferred chiral molecule, but they are difficult to separate and reuse. The IBN technique can make the catalysts in a solid form, thus enabling them to be filtered out with simple filtering and centrifuging techniques. "Using IBN's porous nanoparticles, the pharmaceutical synthesis can be made much more efficient, while retaining the enantiomeric purity of the products," notes Han. "Compared with traditional catalysts, porous nanoparticles would provide greater pore accessibility and facilitate molecular diffusion, which are very important for improving the catalytic activity of the process."

Additional applications for the nanoparticles include carriers for drugs, genes, and proteins for biomedical applications. "IBN's porous nanoparticles can act as the host matrix for the synthesis of quantum dots and magnetic nanoparticles in functional materials and bioimaging applications," says Han.

IBN is in talks with several pharmaceutical companies to commercialize the technology, and hopes it will be on the market within the next two years. A US patent application has been filed.

-–Kaylynn Chiarello