Nanoshells could solve oncology dual delivery riddle

17-Jul-2012 - Last updated on 18-Jul-2012 at 11:10 GMT

Illustration of the nanolipogel administering its immunotherapy cargo.

Hollow nano shells capable of holding both cancer fighting drugs and immune-system boosters could be the solution to oncology’s greatest delivery riddle, according to Yale University researchers.

Researchers have long recognised that effective cancer treatment requires both drugs to fight tumors and agents that can stimulate the immune response. However, simultaneous delivery of the both types of molecules is tricky because - traditionally - it involves packaging large water-soluble drugs in with tiny, water-phobic inhibitors.

Now a team from Yale University believe they have solved the problem with new “shells” – nanolipogels (nLGs) of biodegradable polymers - which when tested in mice proved successful in encompassing and delivering both growth factor-β inhibitor as well as interleukin-2 (IL-2), a conventional cytokine for metastatic melanoma.

“Simply stated, to attack melanoma with some chance of success, both drugs need to be in place at the same location at the same time, and in a safe dosage. The NLGs appear to be able to accomplish the dual treatment with proper targeting and a sustained release that proved safer for the animals undergoing therapy,” the authors said in a statement.

Speaking to in-PharmaTechnologist.com, lead researcher Tarek Fahmy said, if successful in later stages, the method could revolutionise the way drug delivery vehicles are designed.

“What this implies for the industry is that the ability to facilitate tunable combinatorial delivery needs to be seriously considered in the design of future drug delivery vehicles,” he told us.

However, he stressed the technique is not a cure-all answer, adding: “Unfortunately, for complex disease states such as cancer, there is no simple solution and thus sophisticated solutions may need to be sought. Such vehicles are one possible way towards effective combination drug combinations to the tumor environment.”

How the tech works

The nano-vehicles are able to store both molecules by accommodating their differing physiochemical properties Fahmy told us, explaining that: "The hydrophobic molecules are in a hydrophobic compartment and the hydrophilic proteins are in a hydrophilic compartment."

The nanoscale size of the shells allows them to travel safely through the bloodstream until they reach “leaky” vessels associated with the tumor, where they begin degrading and slowly releasing their payloads.

In terms of industrial applications Fahmy said production processes could be scaled up to make large quantities of the shells very quickly because they are made of off-the-shelf-reagents. “Many are currently used pharmaceutical excipients,” he added.

And though the system has only been on primary melanomas, the researchers believe the implications are much wider.

“Most critically, the spherules are engineered to accommodate a wide range of drug shapes and sizes. Ultimately, such a system could prove powerful not only for melanoma, but for a range of cancers,” a spokesperson for the study, published in Nature Materials, said.