Presentation Information
[2I06]Fabrication and evaluation of colloidal tips for elastic modulus measurements of corneocyte using AFM
*Sota Takahashi1, Keisuke Miyazawa1,2, Kenta Sawada1, Amina Miyauchi1, Haruna Hayase3, Junko Kamimoto-Kuroki3, Hiromasa Ikeda3, Keita Adachi3, Takeshi Fukuma1,2 (1. Division of Frontier Engineering, Kanazawa University, 2. Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, 3. KOSE Corporation)
Human skin is composed of corneocytes playing essential roles in protection and moisture retention. While previous studies focused on epidermal investigations, there are few reports on single-corneocyte research. Thus, we have previously developed AFM technique for single-corneocyte measurements. We used colloidal tip with diameter of (D) 8 μm and investigated human corneocytes. However, D=8 μm tip enables only ~20 nm tip indentation length (ZL) with 1.0 μN interaction force, allowing only near-surface measurements. To increase ZL, we reduced contact area between tip and corneocyte by using a smaller tip (D=2 μm). As a result, ZL increased to 60 nm, enabling us to obtain elastic modulus that reflect inside corneocyte. We optimized D suitable for single-corneocyte measurement. We have been using D=2 μm tip to investigate elastic modulus of single-corneocyte in response to humidity variations and cosmetics applications, contributing to understandings of various functions of human skin.