Melanoma nanosensor

Scientists from the Monell Chemical Senses Center (Philadelphia, USA) have developed a nano‑technology sensor for the detection of melanoma.¹ Melanoma arises when melanocytes, pigment-producing cells that give skin its colour, transform to become tumours. The disease is estimated to be responsible for 75% of skin cancer deaths, according to a press release from the center. Detection is largely dependent on self‑examination, and subsequent visual diagnosis by a clinician.

A need for a non-invasive method for the detection of melanoma led the group to consider the volatile organic compounds (VOCs) released by the skin. Based on previous studies, they hypothesized that the VOC profile of melanoma and melanocytes could differ.

Solid-phase micro-extraction (SPME) was performed followed by gas chromatography–mass spectrometry (GC–MS) to determine variations between the VOC profiles of melanocytes and melanoma. Levels of isoamyl alcohol were found to be higher in melanoma cells than melanocytes, and isolvaleric acid lower in melanoma cells. Melanoma cells produced dimethyldi- and trisulphide compounds, not detected from non-melanoma cells.

Recognizing the need for a portable method that could be transferred into a clinical setting, the scientists developed a single-stranded DNA-coated nanotube (DNACNT) sensor to examine VOCs from melanoma and normal cells. The sensor consisted of nano-sized carbon tubes coated with DNA that could be bioengineered to recognize different VOCs associated with other diseases.

The authors concluded that the monitoring of melanoma VOCs has potential in screening methods. A.T. Charlie Johnson (Univeristy of Pennsylvannia), who led the development of the sensor, commented: “We are excited to see that the DNA-carbon nanotube vapour sensor concept has potential for use as a diagnostic. Our plan is to move forward with research into skin cancer and other diseases.”

Reference

1. Jae Kwak et al, Journal of Chromatography B, 931, 90–96 (2013).

This story originally appeared in The Column. Click here to view that issue.