Bio-inspired microneedle design for efficient drug/vaccine coating

Abstract

Biomimetics is the interdisciplinary scientific field focused on the study and imitation of biological systems, with the aim of solving complex technological problems. In this paper, we present a new bio-inspired design for microneedles (MNs) and MN arrays, intended for rapidly coating the MNs with drug/vaccine. The biomimetic approach consists in ornamenting the lateral sides of pyramidal MNs with structures inspired by the external scent efferent systems of some European true bugs, which facilitate a directional liquid transport. To realize these MNs, two-photon polymerization (TPP) technique was used. Liquid coating capabilities of structured and non-structured MNs were compared. Moreover, both in-vivo and ex-vivo skin tests were performed to prove that MNs pierce the skin. We show that the arrays of MNs can be accurately replicated using a micro-moulding technique. We believe this design will be beneficial for the process of drug/vaccine loading onto the needles’ surfaces, by making it more efficient and by reducing the drug/vaccine wastage during MN coating process.Electronic supplementary materialThe online version of this article (10.1007/s10544-019-0456-z) contains supplementary material, which is available to authorized users.

Two-Photon Polymerisation 3D Printing of Microneedle Array Templates with Versatile Designs: Application in the Development of Polymeric Drug Delivery Systems

“…In comparison with other techniques, 2PP shows improved geometry control, as well as scalable resolution, reducing equipment, facilities and maintenance costs commonly associated to etching and lithography-based methods. For this reason, researchers have exploited this technique to fabricate solid or hollow MN arrays using modified ceramics (21,22), inorganic-organic hybrid polymers (23,24), acrylate-based polymers (25,26), polyethylene glycol (27), and recently, water-soluble materials (28), with promising results.…”

Fabrication of novel-shaped microneedles to overcome the disadvantages of solid microneedles for the transdermal delivery of insulin

“…Gill and Prausnitz (2008) reported that MN arrays containing 1,000 needles within a pocket could deliver 100 µg of drug into the skin. Bio-inspired, tear-drop structures on pyramidal MNs increased the liquid coating fluorescence intensity as high as 15 times of that seen using the non-structured MN (Plamadeala et al 2020). In addition, the shape of the coated MN must be designed to deliver the coated drug and overcome the insertion forces into the skin.…”

3D Printing—A “Touch-Button” Approach to Manufacture Microneedles for Transdermal Drug Delivery

“…TPP can easily be scaled up for industrial use, there is no need for cleanroom facilities, and it can use various low-cost materials such as ceramics, polymers, and other photosensitive materials. Many research groups have exploited this technique to fabricate solid [ 108 , 109 , 110 ] or hollow MN arrays [ 143 , 144 , 145 ] as well as reusable MN array molds [ 17 , 146 ].…”