Hepatitis B vaccine delivered by microneedle patch: Immunogenicity in mice and rhesus macaques

Microneedle-Enabled Breakthroughs in Nucleic Acid Therapeutics

Nucleic acid therapy demonstrates great potential in cancer treatment, infectious disease prevention, and vaccine development due to its advantages, such as rapid production, long-lasting effects, and high target specificity. Although nucleic acid therapy is considered ideal for the development of novel therapeutic strategies, its clinical application still faces numerous challenges, including the lack of efficient delivery systems, insufficient drug formulation stability, and the limitations imposed by the skin barrier on drug dosage delivery. Microneedles, as an innovative transdermal drug delivery technology, can penetrate the stratum corneum and directly access the skin's microcirculation, enabling the efficient delivery of genes and drugs. This technology offers several advantages, such as ease of operation, minimally invasive and painless application, and high safety. Combining microneedle technology with nucleic acid therapy fully leverages the strengths of both approaches, significantly enhancing therapeutic efficacy and bioavailability while maximizing treatment potential. This review explores the application prospects and advantages of combining microneedle delivery systems with nucleic acid therapy.

Soft Injectable Sutures for Dose-Controlled and Continuous Drug Delivery

Transdermal drug delivery offers a promising alternative to traditional methods such as oral ingestion and hypodermic injection. Hypodermic injections are painful, while oral ingestion requires higher doses due to enzymatic degradation and poor absorption. While microneedles address the pain issue, they are limited to delivering small amounts of drugs and can be impractical due to peeling off with motion and sweat. Herein, this work proposes soft injectables using drug-carrying sutures for painless and localized sustained delivery in the dermis. These sutures can remain in place during delivery and are suitable for all skin types. Surgical sutures can also serve as open capillary microfluidic channels carrying drug from a wearable drug reservoir to enable long-term (weeks to months) transdermal drug delivery. The experiments focus on delivering 5-fluorouracil (5-FU), a cancer drug, and rhodamine B, a drug model. A fixed-length suture of 60 cm delivers 0.43 mg of 5-flurouracil in 15 min. The experiments also demonstrate a continuous drug delivery of rhodamine B for over 8 weeks at a rate of 0.0195 mL h-1 . The results highlight that soft injectable sutures are promising candidates for long-term sustained delivery of varying quantities of drugs over weeks period compared to hypodermic injection, oral ingestion, or microneedles.

Microneedle-Mediated Transdermal Delivery of Genetic Materials, Stem Cells, and Secretome: An Update and Progression

Medical practitioners commonly use oral and parenteral dosage forms to administer drugs to patients. However, these forms have certain drawbacks, particularly concerning patients' comfort and compliance. Transdermal drug delivery presents a promising solution to address these issues. Nevertheless, the stratum corneum, as the outermost skin layer, can impede drug permeation, especially for macromolecules, genetic materials, stem cells, and secretome. Microneedles, a dosage form for transdermal delivery, offer an alternative approach, particularly for biopharmaceutical products. In this review, the authors will examine the latest research on microneedle formulations designed to deliver genetic materials, stem cells, and their derivatives. Numerous studies have explored different types of microneedles and evaluated their ability to deliver these products using preclinical models. Some of these investigations have compared microneedles with conventional dosage forms, demonstrating their significant potential for advancing the development of biotherapeutics in the future.

Microarray patches: scratching the surface of vaccine delivery

INTRODUCTION

Microneedles are emerging as a promising technology for vaccine delivery, with numerous advantages over traditional needle and syringe methods. Preclinical studies have demonstrated the effectiveness of MAPs in inducing robust immune responses over traditional needle and syringe methods, with extensive studies using vaccines targeted against different pathogens in various animal models. Critically, the clinical trials have demonstrated safety, immunogenicity, and patient acceptance for MAP-based vaccines against influenza, measles, rubella, and SARS-CoV-2.

AREAS COVERED

This review provides a comprehensive overview of the different types of microarray patches (MAPs) and analyses of their applications in preclinical and clinical vaccine delivery settings. This review also covers additional considerations for microneedle-based vaccination, including adjuvants that are compatible with MAPs, patient safety and factors for global vaccination campaigns.

EXPERT OPINION

MAP vaccine delivery can potentially be a game-changer for vaccine distribution and coverage in both high-income and low- and middle-income countries. For MAPs to reach this full potential, many critical hurdles must be overcome, such as large-scale production, regulatory compliance, and adoption by global health authorities. However, given the considerable strides made in recent years by MAP developers, it may be possible to see the first MAP-based vaccines in use within the next 5 years.