title: Evaluation of geometrical effects of microneedles on skin penetration by CT scan and finite element analysis.
abstract: Computerized tomography scan (CT scan) imaging and finite element analysis were employed to investigate how the geometric composition of microneedles affects their mechanical strength and penetration characteristics. Simulations of microneedle arrays, comprising triangular, square and hexagonal microneedle base, revealed a linear dependence of the mechanical strength to the number of vertices in the polygon base. A laser-enabled, micromoulding technique was then used to fabricate 3×3 microneedle arrays, each individual microneedle having triangular, square or hexagonal base geometries. Their penetration characteristics into ex-vivo porcine skin, were investigated for the first time by CT scan imaging. This revealed greater penetration depths for the triangular and square-based microneedles, demonstrating CT scan as a powerful and reliable technique for studying microneedle skin penetration.
authors.affiliation: School of Pharmacy, Cardiff University, CF10 3NB, United Kingdom; School of Science and Technology, Middlesex University, NW4 4BT, United Kingdom. Electronic address: e.loizidou@mdx.ac.uk.
authors.forename: Eriketi Z
authors.initials: EZ
authors.lastname: Loizidou
authors.affiliation: School of Engineering, Cardiff University, CF24 3AA, United Kingdom.
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Inoue
authors.affiliation: School of Pharmacy, Cardiff University, CF10 3NB, United Kingdom.
authors.forename: Johnny
authors.initials: J
authors.lastname: Ashton-Barnett
authors.affiliation: School of Engineering, Cardiff University, CF24 3AA, United Kingdom. Electronic address: Barrow@cardiff.ac.uk.
authors.forename: David A
authors.initials: DA
authors.lastname: Barrow
authors.affiliation: School of Pharmacy, Cardiff University, CF10 3NB, United Kingdom. Electronic address: allendercj@cardiff.ac.uk.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Allender
mesh_terms: D000818:Animals; D020342:Finite Element Analysis; D009339:Needles; D012867:Skin / Q000378:metabolism*; D013552:Swine; D014057:Tomography, X-Ray Computed
keywords: COMSOL; Computerized tomography; Laser ablation; Microfabrication; Microneedles; Skin penetration; Structural mechanics simulations