Microneedle-based ISF Sampling Technique

• PELSA System (Device), also known as PELSA, Hollow Microneedle Sampling System: The PELSA system is a medical device designed to collect dermal interstitial fluid (dISF) using an array of hollow microneedles and controlled subpressure. The procedure involves applying the microneedle array to the skin, followed by extraction and collection of dISF into a capillary tube. Each participant undergoes one sampling session lasting approximately 15 minutes, during which sampling performance, safety, and tolerability are evaluated.

Primary outcomes

• Successful Collection of Dermal Interstitial Fluid [During the sampling session]: Proportion of participants with successful collection of at least 1 µL of dermal interstitial fluid during one PELSA sampling session. The success proportion and its 95% confidence interval will be calculated.

Other outcomes

• Incidence of Device-Related Serious Adverse Events [From device application through 7-day follow-up.]: Number and proportion of participants experiencing device-related serious adverse events during the investigation and follow-up period.
• Participant-Reported Pain During PELSA Sampling [During and immediately after the sampling procedure (Day 1).]: Procedural pain will be assessed using a participant-reported Numerical Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain). Pain scores will be summarized descriptively across participants.
• Local Skin Reactions Following PELSA Sampling [Before and after the sampling procedure (Day 1).]: Standardized photographs of the sampling site will be obtained after the PELSA procedure to document visible skin changes, including erythema, bleeding, or other local reactions. Skin findings will be evaluated descriptively.
• Detectability of Glucose in Collected Dermal Interstitial Fluid [Following dISF collection during the study visit (Day 1).]: The presence of glucose in collected dermal interstitial fluid (dISF) will be assessed using a commercially available glucose measurement system (Contour Next). The proportion of samples yielding a measurable glucose result will be reported descriptively.
• Exploratory Detection of Inflammatory Proteins in Dermal Interstitial Fluid [Samples collected during the study visit (Day 1), with subsequent laboratory analysis.]: A subset of 20 collected dISF samples will undergo exploratory proteomic analysis using the NULISA Inflammatory 250 panel. The analysis will assess the detectability of inflammatory proteins in dISF, including the number and proportion of protein targets detected above the assay-specific detection threshold. Results will be summarized descriptively.

Sex: All, ages: 18 Years to 80 Years, accepts healthy volunteers

Inclusion Criteria:

* Adults aged 18-80 years of age (inclusive) at the time of ICF signature.
* Participant is willing to participate and is capable of giving informed consent.
* Participants must understand and sign the informed consent form, be able to comply with all study procedures and must be available for the duration of the study

Exclusion Criteria:

* Known dermatologic condition at the site of measurement, including active skin injury, lesion, infection or other dermatologic condition
* Pregnant or breastfeeding persons
* The participant has recently taken NSAIDS (within 72 hours of screening), Aspirin (5 days), prescription anticoagulants (e.g. warfarin, 5 days), or P2Y12 antiplatelet therapies (1 week)
* Vulnerable persons
* On persons with an open wound in or near the sampling area.
* On persons with any type of tattoo or piercing anywhere in or near the sampling area.
* On acral skin.

• Markus Magerl, MD, Ph.D., Principal investigator, Charite University, Berlin, Germany