Dissolving Microneedles Can Painlessly Sample Skin for Gene Analysis and Identify Skin Type Biomarkers | Research

The takeaway

Hyaluronate microneedles can painlessly collect skin specimens for gene expression analysis, identifying specific biomarkers — including peptides like cathelicidin and IGF-1 — for different skin types.

33 subjects, 5 skin types profiled with painless microneedles
Full transcriptome analysis from minimally invasive sampling identified specific gene biomarkers including peptides (cathelicidin, IGF-1) for each skin type

What the researchers found

Biocompatible microneedles made of sodium hyaluronate successfully collected skin specimens from 33 subjects for full transcriptome analysis. The researchers identified specific gene biomarkers correlating with five skin conditions: COL1A1, FN1, and PINK1 for skin aging; FLG, KLF4, and LOR for hydration; GPNMB, MLANA, and TYR for pigmentation; IGF1, MPZL3, and AQP3 for oily skin; and PGF, CYR61, RBP4, TAC1, CAMP (cathelicidin antimicrobial peptide), MMP9, MMP3, MMP12, and CCR1 for sensitive skin. The biomarkers correlated with age, device measurements, lactic acid stinging test scores, and visual assessments.

Why it matters

Getting accurate genetic information from skin normally requires a biopsy — an invasive procedure that leaves a wound. This study demonstrates that dissolving microneedles can collect enough RNA for comprehensive gene analysis, opening the door to painless, office-based skin diagnostics. The peptide connection is notable: cathelicidin (CAMP/LL-37), an antimicrobial peptide, emerged as a biomarker for sensitive skin, and IGF-1 (a peptide growth factor) was linked to oily skin.

The numbers in context

n=33 subjects · 5 skin types assessed · Hyaluronate microneedles · Full microarray transcriptome · Multiple biomarkers per skin type

How the study worked

33 subjects with varying skin conditions (aging, dryness, pigmentation, oiliness, sensitivity) were recruited. Skin types were classified using age, non-invasive measurement devices, a 10% lactic acid stinging test, and visual acne assessment. Skin specimens were collected from the face using biocompatible sodium hyaluronate microneedles. Total RNA was extracted and analyzed using microarray-based transcriptome profiling. Correlations between gene expression biomarkers and skin condition parameters were calculated.

Who was studied

33 subjects with different skin conditions (aging, dry, pigmented, oily, sensitive skin)

What this study cannot tell us

Small sample of 33 subjects limits statistical power and generalizability across diverse skin types and ethnicities. The microneedle sampling depth may differ from deeper skin biopsies, potentially missing dermal biomarkers. No comparison to traditional biopsy was included to validate equivalence. The identified biomarkers need replication in larger cohorts.

How to read the evidence

Small proof-of-concept study with 33 subjects. Demonstrates feasibility of microneedle sampling for transcriptomics but requires replication in larger, more diverse cohorts before clinical application.

When this study was published

Published in 2022 in Skin Research and Technology. Microneedle diagnostics is a rapidly advancing field, and this study represents an early demonstration of the sampling-for-analysis approach.

The bigger picture

Microneedle technology is rapidly evolving beyond drug delivery into diagnostics. This study shows microneedles can extract biological information from skin, not just push substances into it. The identification of peptide biomarkers like cathelicidin for sensitive skin connects microneedle diagnostics to the broader field of peptide biology. If validated at scale, this approach could enable precision dermatology — tailoring treatments based on each patient's actual gene expression rather than visual appearance alone.

Questions still open

Can microneedle skin sampling replace traditional biopsies for dermatological gene expression studies?
Does cathelicidin (LL-37) elevation actively contribute to skin sensitivity, or is it merely a marker of inflammation?
Could this technique be used to monitor treatment response in real-time with repeat painless sampling?

Common questions

How do microneedles collect skin samples without pain?

The microneedles used in this study are made of sodium hyaluronate (a naturally occurring skin component) and are tiny enough to penetrate just the surface layers of skin without reaching pain-sensing nerve endings. As they dissolve, they capture cells and RNA that can be analyzed in the lab — no cutting or bleeding required.

What do peptide biomarkers like cathelicidin tell us about skin type?

Cathelicidin (also known as LL-37) is an antimicrobial peptide your skin produces as part of its immune defense. This study found it's elevated in sensitive skin, along with inflammation markers like MMPs. This suggests sensitive skin may involve an overactive innate immune response, with peptides like cathelicidin playing a central role.

Read the original research

Minimally invasive skin sampling and transcriptome analysis using microneedles for skin type biomarker research.

Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging (ISSI), 28(2), 322-335

View on PubMed ↗Publisher’s paper ↗

Citation

Kim, Seo Hyeong; Kim, Ji Hye; Lee, Sung Jae; Jung, Min Sook; Jeong, Do Hyeon; Lee, Kwang Hoon. (2022). Minimally invasive skin sampling and transcriptome analysis using microneedles for skin type biomarker research.. Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging (ISSI), 28(2), 322-335. https://doi.org/10.1111/srt.13135