Microneedles: A New Generation Vaccine Delivery System

Abstract

Transdermal vaccination route using biodegradable microneedles is a rapidly progressing field of research and applications. The fear of painful needles is one of the primary reasons most people avoid getting vaccinated. Therefore, developing an alternative pain-free method of vaccination using microneedles has been a significant research area. Microneedles comprise arrays of micron-sized needles that offer a pain-free method of delivering actives across the skin. Apart from being pain-free, microneedles provide various advantages over conventional vaccination routes such as intramuscular and subcutaneous. Microneedle vaccines induce a robust immune response as the needles ranging from 50 to 900 mm in length can efficiently deliver the vaccine to the epidermis and the dermis region, which contains many Langerhans and dendritic cells. The microneedle array looks like band-aid patches and offers the advantages of avoiding cold-chain storage and self-administration flexibility. The slow release of vaccine antigens is an important advantage of using microneedles. The vaccine antigens in the microneedles can be in solution or suspension form, encapsulated in nano or microparticles, and nucleic acid-based. The use of microneedles to deliver particle-based vaccines is gaining importance because of the combined advantages of particulate vaccine and pain-free immunization. The future of microneedle-based vaccines looks promising however, addressing some limitations such as dosing inadequacy, stability and sterility will lead to successful use of microneedles for vaccine delivery. This review illustrates the recent research in the field of microneedle-based vaccination.

Recent Advances in Polymer Microneedles for Drug Transdermal Delivery: Design Strategies and Applications

“…Hollow MNs are also used for vaccination. [ 161 ] Du et al. [ 166 ] used hollow polymer MNs to deliver nanoparticle vaccines.…”

“…And several companies are developing microneedle-based vaccination (Table 7). [161] Dissolving MNs are composed of polymers with good biocompatibility and biodegradability, and often used for vaccine delivery. [161] Arya et al [162] used dissolving MNs to administrate rabies DNA vaccine to dogs.…”

“…[161] Dissolving MNs are composed of polymers with good biocompatibility and biodegradability, and often used for vaccine delivery. [161] Arya et al [162] used dissolving MNs to administrate rabies DNA vaccine to dogs. The MNs were well tolerated in the skin and no systemic adverse events occurred.…”

Integrating plant molecular farming and materials research for next-generation vaccines

“…Microneedles do not puncture deep enough to activate the nociceptors within the skin and are therefore considered painless. Microneedles can achieve greater immunological responses, compared with traditional routes of administration, such as intramuscular or subcutaneous injection, owing to the abundant immune cell population in the upper layers of the skin, including the Langerhans cells in the epidermis and the dendritic cells in the dermis 135 , 136 . They can also be fabricated to deliver a range of biological vaccines, including inactivated and live attenuated viruses, VLPs and VNPs, protein subunits and DNA 137 .…”

3D Printing for Medical Applications: Current State of the Art and Perspectives during the COVID-19 Crisis

“…Vaccines and therapeutic treatments are currently in development, with several COVID-19 vaccines being widely distributed and administered with haste. This global endeavor is limited by several factors, including supply shortages, critical requirement of cold storage, distribution challenges, and some population aversion to needles or vaccines [54][55][56]. Microneedles are one area of study in addressing these concerns that has been in development since the early 2000s [57].…”