Could a tampon prevent HIV? Silk fibres which dissolve in the body before sex 'will protect women from the virus faster'

A dissolvable tampon could soon offer women faster protection against HIV, scientists say.

Those deemed to be at high risk of contracting HIV in the U.S. are currently prescribed daily drugs, taken orally, to protect against the virus.

But a range of new topical protection methods, including gels and films which can be inserted into the vagina before sex, are currently in development.

A team of researchers at the University of Washington noted the new products were not performing well in clinical trials because they are difficult to use.
And so they have created dissolving fibres, which could be spun and inserted into an applicator, similar to those used to insert tampons.

Bio-engineers believe the tampon could deliver a topical drug, known to protect women from contracting the virus, faster.

Their method spins the drug into silk-like fibres, which quickly dissolve when they come into contact with moisture.

It means higher doses of the drug could be administered than is possible when using gels or creams.
Lead study author Cameron Ball, said: 'This could offer women a potentially more effective, discreet way to protect themselves from HIV infection by inserting the drug-loaded materials into the vagina before sex.'

The findings build on previous research by the team, which found electrically spun cloth could be dissolved to release drugs.

The latest study shows the fibre materials can hold 10 times the concentration of medicine as anti-HIV gels currently in development.

Oral pills are available in the U.S. for people who are considered at risk for HIV infection.

Meanwhile a host of topical medications in the form of gels and films are starting to be developed.

They are placed inside the vagina before sexual intercourse, allowing the drug to dissolve and diffuse into the surrounding issue.
Called microbicides, the drugs must be given as a large dose to be effective minutes before sex.

But to date the topical drugs have not performed well in clinical trials, partly because they were not easy to use.

Drugs in film form take at least 15 minutes to fully dissolve in the body, while the volume of gels must be large enough to deliver a full dose but small enough to prevent leaking.

'The effectiveness of an anti-HIV topical drug depends partially on high-enough dosages and quick release,' Ball said.

'We have achieved higher drug loading in our material such that you wouldn’t need to insert a large amount of these fibres to deliver enough of the drug to be helpful.'

The research team says the soft, dissolving fibres could be rolled into a cardboard tampon applicator for insertion or built into the shape of a vaginal ring, similar to those used for contraception.

The material can accommodate different anti-HIV drugs and the team is testing several others for effectiveness.

Assistant professor Kim Woodrow, who led the research, said: 'We think the fibre platform technology has the capability of being developed into multifunctional medical fabrics that address simultaneously challenges related to biological efficacy and user preferences.'
Source : Daily Mail