Promising New Bloodless Test for Malaria Using Microneedle

Highlights

• Rapid diagnostic tests or RTDs usually use a needle prick for diagnosing malaria are time consuming A blood-free microneedle patch test has been developed for detecting malaria that delivers results within just 20 minutes
• The microneedle-based patch extracts the protein present in dermal interstitial fluid in the skin
• This protein is a biomarker for various infectious diseases like malaria and now, even COVID-19

A microneedle patch will help in the rapid diagnosis of malaria without the need for drawing blood. Researchers from Rice University, who developed the microneedle-based patch test, say that malaria testing could now become as simple as applying a bandage. The self-contained tests deliver results in 20 minutes and require the use of no special equipment or medical expertise. Usually, many infectious diseases are tested using time-consuming, laborious, and expensive laboratory-based microscopy and molecular assays that require the help of trained medical professionals and equipment. These methods also pose the risk of infection or accidental disease transmission.

The findings are detailed in the Nature journal Microsystems and Nanoengineering.

For the procedure, proteins that are present in dermal interstitial fluid are extracted. This fluid is a biomarker for various diseases like malaria and can be used for rapid testing.

People usually recognize this fluid as blisters, but this fluid surrounds all of the cells in the skin.

According to Peter Lillehoj of Rice's Brown School of Engineering, the disposable patches could be programmed to detect other diseases, potentially including COVID-19.

"In this paper, we focus on malaria detection because this project was funded by the Bill and Melinda Gates Foundation, and it's a big priority for them," said Lillehoj, who joined Rice in January as an associate professor of mechanical engineering. "But we can adapt this technology to detect other diseases for which biomarkers appear in interstitial fluid."

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The self-contained test was developed by Lillehoj and lead author Xue Jian.

How the Patch Works

The sticky patch is made up of sixteen hollow microneedles in a 4-by-4 array on one side, along with an antibody-based lateral-flow test strip on the other.

The needles are 375 microns wide and 750 microns long enough to reach the fluid in the skin, which is around 800 to 100 microns thick. Needles are sharp enough to penetrate the skin.

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The needles are attracted to water, and this helps the interstitial fluid to flow in through the test strip.

The antibodies react when they sense protein biomarkers for malaria. If the test is positive, two readout lines on the strip's exposed surface turns red, and if the test is negative, only one line turns red.

The device can be removed like any bandage on the completion of the test.

This experiment is the first to combine both microneedles and antibody test strips into a simple, inexpensive package that can be used at the time of need. The test is particularly useful in developing countries where finger-prick blood sampling and the availability of trained medical personnel to diagnose samples may be challenging.

Lastly, the researchers claim to have self-tested the patch and found it to be pain-free, and user-friendly, especially for children. Lillehoj said "We didn't intend for it to look like a bandage. We started with a rectangular shape and then just rounded the edges to make it a little more presentable. We didn't plan for that, but perhaps it makes the patch more relatable to the general public."

Reference:

1. Microneedle-based skin patch for blood-free rapid diagnostic testing - (https://www.nature.com/articles/s41378-020-00206-1)

Source-Medindia