A new method to extract dermal interstitial fluid (ISF) for analysis has been reported. ISF contains a large number of biomarkers which can be used for diagnosis.
The minimally invasive process uses an array of almost invisibly small needles, approximately one quarter of a millimetre long. These were pressed to the skin and suction applied. Care needed to be taken so that the needles did not poke into microcapillaries in the skin and thus contaminate the sample with blood.
Blood is often used for testing, comprising some 6% of the human body’s fluids, but some 10 000 compounds are found in ISF and 12% of the chemicals are not found in the blood. With the technique, the researchers were also able to measure the effects of glucose and caffeine, which are dynamically active. Traditional methods used to extract are quite invasive; using a needle to withdraw ISF from a vacuum-induced blister, or surgically inserting tubes underneath the skin.
Although the procedure is still time consuming, taking some 20 minutes per patient, it compares to the ~40 minutes required to form a vacuum blister in some ISF sampling protocols. The small needle injuries healed within a day, and there was minimal irritation.
This form of testing could have many applications, such as skin toxicological studies and monitoring glucose levels.
The journal article has been published in Science Translational Medicine.
Source: News-Medical.Net
