Indian Institute of Technology Madras researchers have developed a carbon `nanotube’ that can kill cancer cells without damaging any other cells and tissues.
The group discovered that carbon nanotubes measuring less than one micron in length made by rolling graphene sheets can be used in targeted photodynamic therapy where cancer cells are killed by inducing heat without doing any harm to the body.
The treatment involves targeting cancer cells that are attached with the nanotubes only get heated during the process. IITM has been doing the research in collaboration with Nationa University of Singapore.
Graphene, an atomic layer of graphite in the form of sheet, is rolled to make car bon nanotubes. The inner diameters of these tubes were about 20 to 30 nanometre and the outer diameter 50 to 60 nano metres. Their length could be up to 1,000 nanometre.
Professor and head of alternative energy and nanotechnology laboratory at IIT-M, Sundara Ramaprabhu said these carbon nanotubes have excellent thermal conductivity and have a large surface area to support and carry a drug.
In photodynamic therapy, the professor said, these carbon nanotubes are coated with vitamins and injected into the patient. Folate receptors, a protein, then take the vitamin and carbon nanotubes to the nucleus of the cell, including cancerous cells. Therapists pass infrared radiation in pulses at a wavelength of about 800 nanometre.
With carbon nanotubes possessing good thermal conductivity, heat from radiation passes through the nanomaterial in the cells. Once the temperature rises to 42°C, it kills the cancerous cells. The surrounding cells, which have not absorbed the nanotubes, will remain unaffected.
Researches were also done to check toxicity of the nanomaterial by evaluating the tubes’ length, solubility, concentration and purity. They found carbon nanotubes were less toxic in a range of concentrations normally used, but also are ‘ultrapure’, which means it guarantees safe application.
The researchers say deep analysis is needed before applying the process to different cancers.