Microneedles: A novel clinical technology for evaluating skin characteristics

Abstract

Background: Current methods for evaluating efficacy of cosmetics have limitations because they cannot accurately measure changes in the dermis. Skin sampling using microneedles allows identification of skin-type biomarkers, monitoring treatment for skin inflammatory diseases, and evaluating efficacy of anti-aging and anti-pigmentation products.

Materials and methods: Two studies were conducted: First, 20 participants received anti-aging treatment; second, 20 participants received anti-pigmentation treatment. Non-invasive devices measured skin aging (using high-resolution 3D-imaging in the anti-aging study) or pigmentation (using spectrophotometry in the anti-pigmentation study) at weeks 0 and 4, and adverse skin reactions were monitored. Skin samples were collected with biocompatible microneedle patches. Changes in expression of biomarkers for skin aging and pigmentation were analyzed using qRT-PCR.

Results: No adverse events were reported. In the anti-aging study, after 4 weeks, skin roughness significantly improved in 17 out of 20 participants. qRT-PCR showed significantly increased expression of skin-aging related biomarkers: PINK1 in 16/20 participants, COL1A1 in 17/20 participants, and MSN in 16/20 participants. In the anti-pigmentation study, after 4 weeks, skin lightness significantly improved in 16/20 participants. qRT-PCR showed significantly increased expression of skin-pigmentation-related biomarkers: SOD1 in 15/20 participants and Vitamin D Receptor (VDR) in 15/20 participants. No significant change in TFAP2A was observed.

Conclusion: Skin sampling and mRNA analysis for biomarkers provides a novel, objective, quantitative method for measuring changes in the dermis and evaluating the efficacy of cosmetics. This approach complements existing evaluation methods and has potential application in assessing the effectiveness of medical devices, medications, cosmeceuticals, healthy foods, and beauty devices.

Keywords: in vivo efficacy test; skin aging; skin biomarkers; skin pigmentation.

FIGURE 1

Non‐invasive measurement of skin roughness using PRIMOS. Representative images of crow's feet (A) before and (B) after 4 weeks of using the anti‐aging product. (C) Comparison of average roughness (Ra) values before and after 4 weeks of product use for all participants. Results are displayed as mean ± standard error of the mean of experiments. ^* p < 0.05.

FIGURE 2

Changes in gene expression of skin aging‐related biomarkers detected by qRT‐PCR. The ΔC_T values of (A) PINK1, (B) COL1A1, and (C) MSN before and after 4 weeks of using the test product. Results are displayed as mean ± standard error of the mean of experiments. ^* p < 0.05. ΔC _T, Delta cycle threshold; COL1A1, Collagen type 1 alpha 1 chain; MSN, Moesin; PINK1, PTEN‐induced kinase 1; qRT‐PCR, quantitative real‐time polymerase chain reaction.

FIGURE 3

Non‐invasive measurement of skin lightness using spectrophotometer. Comparison of average lightness (L*) values before and after 4 weeks of use for all participants. Results are displayed as mean ± standard error of the mean of experiments. ^* p < 0.05.

FIGURE 4

Changes in gene expression of skin pigmentation‐related biomarkers detected by qRT‐PCR. The ΔC _T values of (A) TFAP2A, (B) SOD1, and (C) VDR before and after 4 weeks of using the test product. Results are displayed as mean ± standard error of the mean of experiments. ^* p < 0.05. ΔC _T, Delta cycle threshold; qRT‐PCR, quantitative real‐time polymerase chain reaction; SOD1, superoxide dismutase 1; TFAP2A, Transcription Factor AP‐2 Alpha; VDR, Vitamin D receptor.