A noninvasive method for detecting skin surface proteins

Proteins secreted by skin cells are potential biomarkers for skin conditions. Existing methods for detecting proteins on the skin surface have several drawbacks, such as patient discomfort. Korean scientists have created a small enzyme-linked immunospot array on a patch (ELIPatch) which can be used for directly detecting proteins on the skin, as reported in Biomicrofluidics.

ELIPatch is an adhesive patch 16 millimeters in diameter containing an antibody array. Printing devices are often used to assemble these types of arrays, but in this case the researchers achieved a small patch size with high spatial density by adapting microdisks as the antibody carrier. The microdisks are formed using microfluidics-based optofluidic lithography, and self-assemble into microwells in a novel process known as partipetting.

Before use, the polymer chip is covered with circular adhesive tape; the peeling of this adhesive layer transfers the microdisk array onto the tape for securing onto the subject’s skin. After an hour the ELIPatch was removed and sonicated to release the microdisks that contained the antibody captured proteins. A fluorescent immunoassay was then used to quantify the proteins present.

The researchers were able to quantify a range of cytokines from various regions of human skin. “We demonstrated multipoint detection in a 1-centimeter resolution, which cannot be achieved by conventional methods,” said co-author Dong Yoon Oh. The ELIPatch also detected temporal changes in cytokine levels, which was induced when tape-stripping stimuli was applied to volunteers’ inner forearms.

“We believe that ELIPatch offers an easy way to gather profiles of skin surface proteins,” said Oh. He hopes to improve the reproducibility, durability and sensitivity of ELIPatch for the diagnosis of skin conditions, disease progression and response to treatment.

Source: “ELIPatch, a thumbnail-size patch with immunospot array for multiplexed protein detection from human skin surface,” by Dong Yoon Oh, Hunjong Na, Seo Woo Song, Jinhyun Kim, Hyunsoo In, Amos Chungwon Lee, Yunjin Jeong, Daewon Lee, Jisung Jang, and Sunghoon Kwon, Biomicrofluidics (2018). The article can be accessed at https://doi.org/10.1063/1.5032170 .