Dean Ho had been interested in therapeutic drug delivery for some time before a meeting with Eiji Osawa took his research in a new direction. Ho, an assistant professor in the department of biomedical and mechanical engineering at Northwestern University, had experience with cancer therapies; Osawa, who worked for NanoCarbon Research, a private research institute in Nagano, Japan, was an expert on fullerenes and nanocarbons. Osawa had, in fact, proposed that C60 could be a stable form of carbon in 1970 — 15 years before its discovery was published in Nature. Following their interactions with Osawa, Ho and colleagues realized the potential that nanodiamonds had to advance their own research.

Many drugs show promising effects but cannot be delivered effectively because they are insoluble in water. Nanodiamonds, however, can be readily suspended in water when they are functionalized with carboxyl groups. Moreover, Ho and co-workers showed that nanodiamonds can aid the dispersal in water of water-insoluble drugs, making them viable therapeutic candidates (ACS Nano doi:10.1021/nn900480m; 2009). Three water-insoluble anticancer and anti-inflammatory drugs were shown to physisorb onto nanodiamond surfaces and disperse in water, without a reduction in function. The resulting dispersion showed a small aggregate size, improving the chances of the drug entering cells.

Ho enjoyed witnessing the “clear evolution of each researcher towards an appreciation of the challenges that faced each of their colleagues”. The corresponding challenge was maintaining a tight focus: “a large number of researchers can sometimes result in diverging objectives”. According to Ho, overcoming this obstacle involves both formulating objectives that unify the disciplines involved, and communication that begins at the earliest stages: “recognition from the outset that these challenges can be overcome with interaction and dialogue is key.”