Proteins from waste human hair could heal wounds
doi:10.1038/nindia.2019.111 Published online 13 August 2019
An ionic liquid can help extract proteins such as keratin and melanin from waste human hair, research reveals1. Keratin could potentially be used for wound healing, drug delivery and tissue engineering, while melanin could be used for bioimaging.
Human hair is usually thrown away as waste. It contains proteins along with lipids, water and a small amount of trace elements that are difficult to dissolve and extract.
To devise an efficient way to extract proteins from hair, scientists from the CSIR-Central Salt & Marine Chemicals Research Institute in Gujarat, India, prepared a biodegradable hydrated ionic liquid using tetrabutyl ammonium hydroxide. They then explored the efficiency of the ionic liquid in extracting proteins from waste human hair.
The team found that the liquid dissolved 25 per cent of the weight of human hair at room temperature within nine hours. It yielded 22 per cent melanin and 38 per cent keratin. The moisture contents of the extracted keratin and melanin were similar to that of standard keratin and melanin.
They also found that the structures of the hair proteins remained unaltered even after dissolution in the ionic liquid. Adding water to the liquid also enhanced the solubility of human hair, showing water’s role in the dissolution process.
The ionic liquid left behind following the extraction of hair proteins contained nitrogen. This could be used to fortify a nitrogen-deficient liquid seaweed plant biostimulant. “It would be potentially useful for agricultural purposes in the form of leaf spray and solid formulations,” says lead researcher Kamalesh Prasad.
1. Singh, N. et al. Multi-tasking hydrated ionic liquids as sustainable media for the processing of waste human hair: a biorefinery approach. Green. Chem.21, 3328-3333 (2019)