Research Highlights

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  • Biotechnology

Published online: 31 January 2007 | doi:10.1038/nchina.2007.070131-1

Practical pharmacology: Getting under the skin

Kaspar Mossman

Introduction

Many diabetics have no option but to control their metabolism with regular, painful injections of insulin. Insulin cannot be taken orally because it is degraded by stomach enzymes. However, Yongping Chen and co-workers¹ at the University of Science and Technology of China in Hefei have identified a short peptide that increases the skin's permeability and may allow the production of insulin in ointment form.

The researchers used a technique known as 'phage display'. Phages are viruses whose coats consist of thousands of copies of a single protein. Fusing this protein with candidate peptides, Chen and co-workers generated a large library of phages, each 'displaying' one peptide. They applied these phages to the bellies of mice and assayed their blood. All the phages that penetrated the skin displayed the same peptide, TD-1.

Treatment of skin with pure TD-1 enhanced the penetration of phages not expressing TD-1. This suggested that TD-1 might assist the transfer of large molecules across the skin. Indeed, when insulin (to which skin is impermeable) and TD-1 were rubbed on at the same time, blood sugar levels in the mice increased abruptly to levels similar to those induced by injected insulin. The researchers demonstrated similar results when human growth hormone was administered with TD-1.

References

1. Chen, Y. et al. Transdermal protein delivery by a coadministered peptide identified via phage display. Nature Biotech. 24, 455–460 (2006). | Article |