Exploiting Unique Features of Microneedles to Modulate Immunity

Abstract

Microneedle arrays (MNAs) are small patches containing hundreds of short projections that deliver signals directly to dermal layers without causing pain. These technologies are of special interest for immunotherapy and vaccine delivery because they directly target immune cells concentrated in the skin. The targeting abilities of MNAs result in efficient immune responses—often more protective or therapeutic—compared to conventional needle delivery. MNAs also offer logistical benefits, such as self‐administration and transportation without refrigeration. Thus, numerous preclinical and clinical studies are exploring these technologies. Here we discuss the unique advantages of MNA, as well as critical challenges – such as manufacturing and sterility issues – the field faces to enable widespread deployment. We explain how MNA design parameters can be exploited for controlled release of vaccines and immunotherapies, and the application to preclinical models of infection, cancer, autoimmunity, and allergies. We also discuss specific strategies to reduce off‐target effects compared to conventional vaccine delivery routes, and novel chemical and manufacturing controls that enable cargo stability in MNAs across flexible intervals and temperatures. We then examine clinical research using MNAs. We conclude with drawbacks of MNAs and the implications, and emerging opportunities to exploit MNAs for immune engineering and clinical use.This article is protected by copyright. All rights reserved

Diffusion Idiopathic Skeletal Hyperostosis (DISH), a Link between Gut Microbiota and Spinal Degenerative Diseases<strong> </strong>

“…Immune tolerance refers to the ability of the immune system to recognize and tolerate harmless substances, such as allergens or the body's own tissues, without mounting an unnecessary or harmful immune response. This state of balance is crucial for preventing immune overreactions, allergies, and autoimmune conditions, where the immune system mistakenly attacks the body's own cells and tissues [74,75]. The presence of diverse gut microbes helps educate immune cells, teaching them to differentiate between beneficial microorganisms and potentially harmful invaders.…”

Efficient Loading and Sustained Delivery of Methotrexate Using a Tip-Swellable Microneedle Array Patch for Psoriasis Treatment

“…5 Because subcutaneous tissues are rich in loosely packed fat cells and well-vascularized, MTX is cleared quickly. 6 Similar to oral administration, S.C. injection also leads to inadequate accumulation of MTX in the psoriatic region, which is situated in the upper layers of the subcutaneous tissue, namely, the epidermis and dermis. 7 Therefore, an alternative administration route is highly desirable to improve therapeutic efficacy and minimize the toxic effects of MTX.…”

“…However, S.C. injection is inconvenient and painful and causes needle-phobia, which leads to the poor patient compliance . Because subcutaneous tissues are rich in loosely packed fat cells and well-vascularized, MTX is cleared quickly . Similar to oral administration, S.C. injection also leads to inadequate accumulation of MTX in the psoriatic region, which is situated in the upper layers of the subcutaneous tissue, namely, the epidermis and dermis .…”

Polymeric Microneedles Enhance Transdermal Delivery of Therapeutics

“…The parenteral delivery (subcutaneous injection) of MTX receives poor acceptability, inconvenience, and patient incompatibility, as this route is associated with needle phobia and trained healthcare givers [20]. Subcutaneous tissues, abundant with loosely packed fat cells and well-vascularized, cause MTX to be cleared rapidly [21]. Therefore, subcutaneous injection resulted in insufficient delivery and an accumulation of MTX in the psoriatic lesions [22].…”