Research Highlights

• Subject Category:
  • Biotechnology

Published online: 8 July 2009 | doi:10.1038/nchina.2009.139

Nanobiotechnology: 'Penicillin' for the brain

Felix Cheung

Introduction

© (2009) Nature Nanotechnology

Although cases are rare, a handful of bacteria, such as Staphylococcus aureus, can infiltrate across the blood–brain barrier (BBB), which normally safeguards the brain, to cause inflammatory damage. Such infections can lead to hearing loss, learning disability, brain damage — and even death. An international team of researchers led by Lanjuan Li at Zhejiang University in Hangzhou, China, and Yi Yan Yang at the Institute of Bioengineering and Nanotechnology in Singapore¹ has developed a novel class of nanoparticles to combat these BBB infiltrators.

TAT is a short, cationic antimicrobial peptide that is effective against a wide range of bacteria, yeasts and fungi. Although the exact mechanism of killing is unclear, scientists believe that the amino acid composition and cationic charge are two factors that allow TAT to penetrate and disintegrate the cell membrane of these pathogens.

The researchers designed a peptide called CG₃R₆TAT, comprising a cell-penetrating TAT, six arginine residues, three glycine residues and a cholesterol molecule. The arginine residues help boost the cationic charge of the peptide, and the cholesterol helps the peptide self-assemble into a core–shell nanoparticle (see image).

The nanoparticles were effective against S. aureus infection in mice and were more potent than TAT peptides due to the boosted cationic charge. The nanoparticles also crossed the BBB of S. aureus-infected rabbits and suppressed bacterial growth inside the brain.

Based on these findings, the researchers anticipate that their nanoparticles will be effective against brain infections and other infectious diseases.

The authors of this work are from:
Institute of Bioengineering and Nanotechnology, Singapore, Singapore; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China; Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, USA; School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore.

Reference

1. Liu, L. et al. Self-assembled cationic peptide nanoparticles as an efficient antimicrobial agent. Nature Nanotechnol. doi:10.1038/nnano.2009.153 (2009). | Article |