VATIS UPDATE Article

A team of researchers at Fudan University, China, have discovered that a traditional plant-based Chinese ink called Hu-Kaiwen ink contains distinctive molecular properties that aren’t just suited to inscribing messages on paper – they’re also ideal for killing cancer cells. Researchers began looking into Hu-Kaiwen ink (aka Hu-ink) after noticing its similarities to artificial nanomaterials used in an emerging cancer treatment called photothermal therapy (PTT).

PTT involves injecting substances containing these nanomaterials into tumours in the body, which are then targeted by a laser. Once the laser hits the nanomaterial package deployed in the cancer cells, the cells heat up and die. A number of artificial nanomaterials have been investigated by researchers looking into PTT – including engineered carbon nanotubes and graphene – but have been found to be either toxic, expensive to produce, or difficult to make.

But the slick, black consistency of Hu-Kaiwen ink looked like it might tick all the boxes scientists are looking for in a PTT candidate: the right colour for absorbing light and heat, stable in water, not prohibitively expensive or complex, and – importantly – not toxic to the body. For testing, the researchers analysed the ink in an aqueous dispersion and found it consisted of aggregates of small carbon nanoparticles, which could heat up to 55 °C (131 °F) after just 5 minutes of near-infrared irradiation – greater thermal absorption than most artificial PTT materials.