London: Scientists have developed an synthetic spider silk infused with antibiotic that can be used in drug delivery, regenerative medicine and wound healing.
Researchers for the first time showed how 'click-chemistry' can be used to attach molecules, such as antibiotics or fluorescent dyes, to artificially produced
spider silk synthesised by E coli bacteria. The chosen molecules can be 'clicked' into place in soluble silk protein before it has been turned into fibres, or after the fibres have been formed.
This means that the process can be easily controlled and more than one type of molecule can be used to 'decorate' individual silk strands. Researchers at University of Nottingham in the UK developed and diversified this new approach to functionalising 'recombinant' artificial spider silk with a wide range of small molecules.
They have shown that when these 'silk' fibres are 'decorated' with the antibiotic levofloxacin it is slowly released from the silk, retaining its anti-bacterial activity
for at least five days. "Our technique allows the rapid generation of biocompatible, mono or multi-functionalised silk structures for use in a wide range of applications," said Neil Thomas, from University of Nottingham.
"These will be particularly useful in the fields of tissue engineering and biomedicine," Thomas said. Spider silk is strong, biocompatible and biodegradable. It is a protein-based material that does not appear to cause a
strong immune, allergic or inflammatory reaction.
With the recent development of recombinant spider silk, the race has been on to find ways of harnessing its remarkable qualities. The technique can be used to create a biodegradable mesh which can do two jobs at once, researchers said.
It can replace the extra cellular matrix that our own cells generate, to accelerate growth of the new tissue.
It can also be used for the slow release of antibiotics. "There is the possibility of using the silk in advanced dressings for the treatment of slow-healing wounds such as diabetic ulcers," said Thomas. "Using our technique infection could be prevented over weeks or months by the controlled release of antibiotics," he said.
"At the same time tissue regeneration is accelerated by silk fibres functioning as a temporary scaffold before being biodegraded," Thomas said. The medicinal properties of spider silk have been recognised for centuries but not clearly understood. The Greeks and Romans treated wounded soldiers with spider webs to stop bleeding.
It is said that soldiers would use a combination of honey and vinegar to clean deep wounds and then cover the whole thing with balled-up spider webs, researchers said. The research was published in the journal Advanced Materials.
