Responsive Microneedles as a New Platform for Precision Immunotherapy

Abstract

Microneedles are a well-known transdermal or transdermal drug delivery system. Different from intramuscular injection, intravenous injection, etc., the microneedle delivery system provides unique characteristics for immunotherapy administration. Microneedles can deliver immunotherapeutic agents to the epidermis and dermis, where immune cells are abundant, unlike conventional vaccine systems. Furthermore, microneedle devices can be designed to respond to certain endogenous or exogenous stimuli including pH, reactive oxygen species (ROS), enzyme, light, temperature, or mechanical force, thereby allowing controlled release of active compounds in the epidermis and dermis. In this way, multifunctional or stimuli-responsive microneedles for immunotherapy could enhance the efficacy of immune responses to prevent or mitigate disease progression and lessen systemic adverse effects on healthy tissues and organs. Since microneedles are a promising drug delivery system for accurate delivery and controlled drug release, this review focuses on the progress of using reactive microneedles for immunotherapy, especially for tumors. Limitations of current microneedle system are summarized, and the controllable administration and targeting of reactive microneedle systems are examined.

Advances in biomedical systems based on microneedles: design, fabrication, and application

“…Numerous reviews have comprehensively outlined microneedles’ various applications and prospects in immunotherapy and vaccines. 230–232 These reviews have consistently affirmed the effectiveness of vaccine delivery platforms based on microneedles. Such platforms exhibit superiority by diminishing dosage requirements, augmenting immunogenicity, enhancing vaccine stability, and improving patient adherence.…”

Biomaterial-Based Sustained-Release Drug Formulations for Localized Cancer Immunotherapy

“…62 These can form dermal drug depots and can be decomposed via enzymatic reactions and/or hydrolysis to achieve drug release in a controlled and sustained manner. 143 Microneedle patches are designed to penetrate subcutaneous barriers to reach deeper target lesions at the local injection site and subsequently implant the drugs packaged within or coated on microneedles of various structural and morphological layouts. The backing layer can also be used as a drug reservoir to boost the loading of drugs that are then transported through microneedle channels for local delivery.…”

“…More importantly, polymers can be used to construct biodegradable microneedle platforms by manipulating their composition and degradation rate . These can form dermal drug depots and can be decomposed via enzymatic reactions and/or hydrolysis to achieve drug release in a controlled and sustained manner . Microneedle patches are designed to penetrate subcutaneous barriers to reach deeper target lesions at the local injection site and subsequently implant the drugs packaged within or coated on microneedles of various structural and morphological layouts.…”

Hydrogel Microneedles with Programmed Mesophase Transitions for Controlled Drug Delivery

“…These MNs can release their payloads in response to endogenous or exogenous stimuli, such as pH, reactive oxygen species, light, temperature, enzymes, and mechanical forces. Such MNs can be used to deliver drugs in a more controllable manner, improve the therapeutic efficacy, reduce potential side effects, and provide a precise dosing. − …”

“…Such MNs can be used to deliver drugs in a more controllable manner, improve the therapeutic efficacy, reduce potential side effects, and provide a precise dosing. 17 − 19 …”