A Malaysian research team has developed a simple, low-cost and environmentally friendly method for producing nanoparticles for use in biomedical applications such as the repair of fractured bone.

Andrew Butko

The team successfully synthesized “aragonite” nanoparticles (ANPs) from the cockle shell, an inexpensive and abundant resource. Aragonite is one of three naturally occurring forms of the mineral calcium carbonate (CaCO3) and has been extensively studied because of its biocompatible properties — it can be integrated with and replaced by bone. Aragonite is also being used to produce advanced drug delivery systems and scaffolds for bone repair and tissue engineering.

Previously, scientists have described two main methods for synthesizing ANPs for biomedical applications: one involving the combination of different pairs of chemicals in an aqueous solution; the other a carbonation process in which carbon dioxide gas is bubbled through an aqueous slurry of calcium hydroxide at a specified temperature in the presence of organic substrates. However, neither method yields pure aragonite nanoparticles of suitable sizes and shapes: the resulting ANPs are often mixed with other forms of calcium carbonate. What’s more, the carbonation process requires stringent temperature control, purified raw materials, and laborious gas bubbling steps, which are complicated and incur additional cost and time.

By contrast, the new production method is a simple, “top-down” approach in which cockle shell powders are mechanically ground in the presence of a non-toxic catalyst called dodecyl dimethyl betaine (BS-12). This method yields ANPs with an average diameter of 20 nm — the smallest so far reported. “The beauty of [our] method is that it does not add any impurities to the final products but still produces very small-sized rod-shaped ANPs in a reproducible fashion, a criterion required for industrial applications,” explain the authors in a recent issue of the journal Powder Technology.

 

For further information, contact:

Md Zuki Bin Abu Bakar

Faculty of Veterinary Medicine

Universiti Putra Malaysia

Email: zuki@vet.upm.edu.my