3D Printing of Biodegradable Polymeric Microneedles for Transdermal Drug Delivery Applications

Abstract

Microneedle (MN) technology is an optimal choice for the delivery of drugs via the transdermal route, with a minimally invasive procedure. MN applications are varied from drug delivery, cosmetics, tissue engineering, vaccine delivery, and disease diagnostics. The MN is a biomedical device that offers many advantages including but not limited to a painless experience, being time-effective, and real-time sensing. This research implements additive manufacturing (AM) technology to fabricate MN arrays for advanced therapeutic applications. Stereolithography (SLA) was used to fabricate six MN designs with three aspect ratios. The MN array included conical-shaped 100 needles (10 × 10 needle) in each array. The microneedles were characterized using optical and scanning electron microscopy to evaluate the dimensional accuracy. Further, mechanical and insertion tests were performed to analyze the mechanical strength and skin penetration capabilities of the polymeric MN. MNs with higher aspect ratios had higher deformation characteristics suitable for penetration to deeper levels beyond the stratum corneum. MNs with both 0.3 mm and 0.4 mm base diameters displayed consistent force–displacement behavior during a skin-equivalent penetration test. This research establishes guidelines for fabricating polymeric MN for high-accuracy and low-cost 3D printing.

Microneedles Based on a Biodegradable Polymer—Hyaluronic Acid

“…Among the additive manufacturing methods, the SLA technique was used to produce microneedles based on biodegradable polymers, resulting in MNs with high quality and strength. This study showed that it is possible to prepare microneedles from biodegradable polymers using the SLA technique and opened up new possibilities for the design and production of modern MNs [102].…”

Determination of vat-photopolymerization parameters for microneedles fabrication and characterization of HPMC/PVP K90 dissolving microneedles utilizing 3D-printed mold

“…However, SLA can be used to construct solid MN with the desired height, diameter and shape, and those of 3D-printed solid MNs can be utilized to fabricate MN mold. Nowadays, vat photopolymerization had been reported for printing pyramidal and cone shape microneedles 7 – 10 by adjusting printing angle 7 , 9 , needle height 7 and needle to needle spacing 9 , 11 . However, there are three essential parameters, such as curing time 12 , printing angle 9 , 13 and anti-aliasing 14 that impacted needles appearance because these three vital parameters influence the size 12 , 15 , sharpness 13 , shape and smoothness of the needles 16 .…”