Starpharma has been on the Australian biotech scene for some time now and is progressing very nicely indeed with its wide portfolio of applications for the company's dendrimer-based nanotechnology.

In the last year, it has announced deals with some big names in the biotech and pharma world, including SSL, manufacturer of the world's leading condom brand, Durex; EMD Biosciences, which is part of Merck KgaA.; Unilever, and Stiefel Laboratories, the world's largest independent specialist in dermatological pharmaceuticals.

All of those deals are for distinct, seemingly unrelated applications - one for a coating on condoms, one for a siRNA transfection kit and the other for drug delivery purposes - but all are based on the company's dendrimer technology.

It is also in Phase II expanded safety trials for its microbicide VivaGel, under development for the prevention of transmission of HIV and HSV-2 (genital herpes), and there are potential applications in human papillomavirus (HPV) in the future.

The compound has also been shown in animal models to be an effective contraceptive.

Dr Jackie Fairley, the company's CEO since 2006, describes dendrimers as highly defined large molecules or nano-particles.

"They are much larger than a typical drug and are more similar in size to something like a protein in the body, like albumin," she says. "They are a highly defined synthetic macro-molecule, very versatile in their potential applications."

Dendrimers can be used as drugs themselves, as in VivaGel, but also as drug delivery agents, she says. "They can act as a scaffold to carry other drugs, such as small molecule drugs or protein drugs, and they also can be used in diagnostics and the delivery of siRNA and non-pharmaceutical and non-life science applications.

"If you think of them as a class, an analogy might be something like when the class of silicons were discovered -they had very broad applications in a whole lot of areas."

The technology was first developed some years ago by the now defunct Biomolecular Research Institute and forms the platform technology of Starpharma, which was set up by founding scientist Professor Peter Colman and founding CEO John Raff. It also includes the work of US based Dendritic Nanotechnologies, a company acquired by Starpharma two years ago.

The company constructs dendrimers by taking a small core molecule and then repeatedly adding a lysine branching unit until a spherical nano-particle is created.

SPL7013 is its lead candidate and forms the active ingredient in VivaGel, a topical vaginal microbicide which Starpharma believes is the only microbicide in clinical development for the prevention of transmission of HIV and genital herpes.

"It is a topical gel not dissimilar to something like a lubricant gel," Fairley says. "It is a water-based, colourless, tasteless and odourless gel and it contains one of these dendrimers, which is an antiviral agent. It is delivered using an applicator, 3.5 grams of gel delivered prior to intercourse and the antiviral component of the gel interacts with viral particles which the woman is exposed to, inactivating those particles to prevent them from invading the human cells."

VivaGel has some high level backing, with the US FDA giving it Fast Track status and the US National Institutes for Health granting Starpharma US$20 million for the HIV aspect and further funding for genital herpes.

It is the only genital herpes microbicide trial with funding from the NIH. While the market in the developed world for a topical microbicide is obvious, it is the potential in the developing world that has raised a great deal of interest.

"Condom use, whether it is in developing or developed countries, is extraordinarily low, even though they are a well-established, effective means of preventing the spread of diseases like HIV," Fairley says. "But you would find in areas like Africa where HIV is a huge problem condom usage is quite low.

"Vaccine strategies for HIV and genital herpes have proven to be unsuccessful. None of them have been shown to have acceptable results in trials so as a result of that microbicides offer the only option for prevention apart from abstinence or condoms.

"So there is obvious application in developing countries but this product is a very attractive concept in the developed world as well because women want to have control over their own health outcomes.

"Market research tells us very strongly that women are far more concerned about sexually transmitted diseases than men are and rightly they should be because it is much easier to become infected as a woman. So it's the ability to have control over your own health and protect yourself, independent of whatever happens later in the evening and whether or not a condom is used."