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Microneedles (µND) are promising devices that can be used to transport a wide variety of active compounds into the skin. To serve as an effective delivery system, µND must pierce the human stratum corneum (~10–20 µm), without breaking or buckling during penetration. In the current review, we discuss both the anatomical features and biomechanical properties of skin in order to understand the local environment and resistive forces relevant to µNDs insertion. Of particular importance are the factors that affect µND insertion, such as their geometry and material composition, as these can be manipulated in the design and development phase to optimise skin insertion. We review the research relevant to µND and how this interacts with skin properties. We have also reviewed the most commonly used skin drug diffusion modelling used to predict drug behaviour from µNDs, and discussed the current challenges faced by µNDs to enter clinical trials and provide positive clinical outcomes.


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Skin biomechanics: Breaking the dermal barriers with microneedles

Show Author's information Masood Ali1Sarika Namjoshi1Heather A. E. Benson2,3( )Tushar Kumeria4,5( )Yousuf Mohammed1( )
Therapeutics Research Group, The University of Queensland Diamantina Institute, Faculty of Medicine, The University of Queensland, Brisbane, QLD 4102, Australia
Clinical and Health Sciences, University of South Australia, Adelaide, SA 5001, Australia
Curtin Medical School, Curtin University, Perth, WA 6845, Australia
School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
Australian Centre for Nanomedicine, The University of New South Wales, Sydney, NSW 2052, Australia

Abstract

Microneedles (µND) are promising devices that can be used to transport a wide variety of active compounds into the skin. To serve as an effective delivery system, µND must pierce the human stratum corneum (~10–20 µm), without breaking or buckling during penetration. In the current review, we discuss both the anatomical features and biomechanical properties of skin in order to understand the local environment and resistive forces relevant to µNDs insertion. Of particular importance are the factors that affect µND insertion, such as their geometry and material composition, as these can be manipulated in the design and development phase to optimise skin insertion. We review the research relevant to µND and how this interacts with skin properties. We have also reviewed the most commonly used skin drug diffusion modelling used to predict drug behaviour from µNDs, and discussed the current challenges faced by µNDs to enter clinical trials and provide positive clinical outcomes.

Keywords:

skin thickness, skin viscoelasticity, skin layers, microneedles, skin penetration, stratum corneum, viable epidermis and dermis
Received: 05 January 2022 Revised: 29 January 2022 Accepted: 16 February 2022 Published: 26 February 2022 Issue date: March 2022
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Publication history

Received: 05 January 2022
Revised: 29 January 2022
Accepted: 16 February 2022
Published: 26 February 2022
Issue date: March 2022

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© The Author(s) 2022. Nano TransMed published by Tsinghua University Press.

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