Targeting system for photodynamic antimicrobial drug

Research lead | Licensing opportunity

Attaching a light-activated (photodynamic) antimicrobial drug to a peptide that binds to the bacterium methicillin-resistant Staphylococcus aureus (MRSA), is effective in killing the so-called superbug, claims a team from University College London.

Linda Dekker and colleagues from the UCL Eastman Dental Institute, University College London, have improved the efficiency of photodynamic therapy using tin chlorin e6, which produces free radicals and unstable singlet oxygen when exposed to light of a particular wavelength, by linking it to a RNAIII inhibiting peptide (RIP) that binds to the surface of MRSA.

This improves the effectiveness of treatment and avoids damage to human cells. In total, 99.97 per cent of 10 million MRSA cells were killed using this combination, which was 1,000 times more effective at killing MRSA than commercially available tin chlorin e6 when the same quantity is used.

In addition to being far more effective at killing the bacteria, the new drug has the potential to prevent bacteria from producing tissue-damaging toxins. The mechanism of killing makes it unlikely that bacteria can develop resistance to the treatment.

“The results from laboratory studies are very encouraging and indicate that this technique might be effective at treating topical infections such as wound and burn infections,” said Dekker. “This work will require in vivo trials before it can be used.”