Dissolvable polymer microneedles for drug delivery and diagnostics.

Dissolvable transdermal microneedles (µND) are promising micro-devices used to transport a wide selection of active compounds into the skin. To provide an effective therapeutic outcome, µNDs must pierce the human stratum corneum (~10 to 20 µm), without rupturing or bending during penetration, then release their cargo at the predetermined area and time. The ability of dissolvable µND arrays/patches to sufficiently pierce the skin is a crucial requirement, which depends on the material composition, µND geometry and fabrication techniques. This comprehensive review not only provides contemporary knowledge on the µND design approaches, but also the materials science facilitating these delivery systems and the opportunities these advanced materials can provide to enhance clinical outcomes.

Transdermal drug delivery systems for fighting common viral infectious diseases.

Transdermal drug delivery systems (TDDS) have many advantages and represent an excellent alternative to oral delivery and hypodermic injections. TDDS are more convenient and less invasive tools for disease and viral infection treatment, prevention, detection, and surveillance. The emerging development of microneedles for TDDS has facilitated improved skin barrier penetration for the delivery of macromolecules or hydrophilic drugs. Microneedle TDDS patches can be fabricated to deliver virus vaccines and potentially provide a viable alternative vaccine modality that offers improved immunogenicity, thermostability, simplicity, safety, and compliance as well as sharp-waste reduction, increased cost-effectiveness, and the capacity for self-administration, which could improve vaccine distribution. These advantages make TDDS-based vaccine delivery an especially well-suited option for treatment of widespread viral infectious diseases including pandemics. Because microneedle-based bioassays employ transdermal extraction of interstitial fluid or blood, they can be used as a minimally invasive approach for surveying disease markers and providing point-of-care (POC) diagnostics. For cutaneous viral infections, TDDS can provide localized treatment with high specificity and less systemic toxicity. In summary, TDDS, especially those that employ microneedles, possess special attributes that can be leveraged to reduce morbidity and mortality from viral infectious diseases. In this regard, they may have considerable positive impact as a modality for improving global health. In this article, we introduce the possible role and summarize the current literature regarding TDDS applications for fighting common cutaneous or systemic viral infectious diseases, including herpes simplex, varicella or herpes zoster, warts, influenza, measles, and COVID-19.