The researchers say that an ammonium salt in the drug was the main cause of harmful side effects, and that reducing it was just not possible because it would render the drug useless against HIV by disabling the resulting molecule to bind to the virus tightly.
Now, they insist, their study has shown some promise in improving the efficacy of the drug (without in binding the ammonium salt) in binding to HIV by combining it with gold nanoparticles.
The researchers said that they have found the drug-gold nanoparticle combination to be effective enough to prevent HIV from infecting lab-cultured white blood cells.
Their experiments showed that when each nanoparticle was equipped, on average, with 12 drug molecules, the drug appeared to be as effective against HIV as the original version with the side effect-inducing ammonium salt.
"We took a small molecule that isn't active on its own, conjugated it to the gold nanoparticle, and suddenly it's a very good inhibitor of HIV," Discovery News quoted T. Eric Ballard, one of the authors of the study that was recently published online in the Journal of the American Chemical Society, as saying.
He, however, conceded that it would require extensive testing before it could be used on patients.
David Margolis, who jointly authored the study with Ballard, revealed that their team's next effort would be to attach an antiviral drug and a glucose molecule to the nanoparticles, and see if they could be transported across the blood-brain barrier.
He said that creating such a virus-killing drug in the brain is something that has not been possible before.
Hamad-Schifferli, an expert at the Massachusetts Institute of Technology who was not involved in the study, said that the same technique could eventually be put to use in treatments for a variety of diseases.