A cure may be on the way for skin diseases with the creation of the world's first nanoneedle that can deliver healthy genes directly into the affected skin cells and repair them.
The research at City University spells hope for people for whom treatment alleviates the symptoms but does not cure the condition, researchers say.
The needle is made of diamond, the planet's hardest natural material, with a tip just 135 nanometres in diameter, more than 5,000 times thinner than a human hair. Ten million nanometres equals 1cm.
The needle can penetrate a cell membrane without killing the cell, said Dr Chen Xianfeng, an assistant professor in the department of physics and material science who first came up with the idea of nanoneedles in 2011.
"Unlike traditional medical treatment that treats only the symptoms but not the cause, our nanoneedle can be used to fix the diseased skin cells directly by delivering the correct genes to them," Chen said.
The researchers hope to treat psoriasis - which causes dry red patches on the skin and may increase the risk of stroke - and melasma, which refers to dark patches on the face and is common in pregnant women.
In its study, Chen's team arranged up to a million needles on a 1 sq cm plate and used them on a nerve cell known as the neuron.