Microarray patches for managing infections at a global scale.

Since the first patent for micro array patches (MAPs) was filed in the 1970s, research on utilising MAPs as a drug delivery system has progressed significantly, evidenced by the transition from the simple 'poke and patch' of solid MAPs to the development of bio responsive systems such as hydrogel-forming and dissolving MAPs. In addition to the extensive research on MAPs for improving transdermal drug delivery, there is a growing interest in using these devices to manage infectious diseases. This is due to the minimally invasive nature of this drug delivery platform which enable patients to self-administer therapeutics without the aid of healthcare professionals. This review aims to provide a critical analysis on the potential utility of MAPs in managing infectious diseases which are still endemic at a global scale. The range of diseases covered in this review include tuberculosis, skin infections, malaria, methicillin-resistant Staphylococcus aureus infections and Covid-19. These diseases exert a considerable socioeconomic burden at a global scale with their impact magnified in low- and middle-income countries (LMICs). Due to the painless and minimally invasive nature of MAPs application, this technology also provides an efficient solution not only for the delivery of therapeutics but also for the administration of vaccine and prophylactic agents that could be used in preventing the spread and outbreak of emerging infections. Furthermore, the ability of MAPs to sample and collect dermal interstitial fluid that is rich in disease-related biomarkers could also open the avenue for MAPs to be utilised as a minimally invasive biosensor for the diagnosis of infectious diseases. The efficacy of MAPs along with the current limitations of such strategies to prevent and treat these infections will be discussed. Lastly, the clinical and translational hurdles associated with MAP technologies will also be critically discussed.

Formulation of antiretroviral nanocrystals and development into a microneedle delivery system for potential treatment of HIV-associated neurocognitive disorder (HAND).

HIV/AIDS remains a major global public health issue. While antiretroviral therapy is effective at reducing the viral load in the blood, up to 50% of those with HIV suffer from some degree of HIV-associated neurocognitive disorder, due to the presence of the blood-brain barrier restricting drugs from crossing into the central nervous system and treating the viral reservoir there. One way to circumvent this is the nose-to-brain pathway. This pathway can also be accessed via a facial intradermal injection. Certain parameters can increase delivery via this route, including using nanoparticles with a positive zeta potential and an effective diameter of 200 nm or less. Microneedle arrays offer a minimally invasive, pain-free alternative to traditional hypodermic injections. This study shows the formulation of nanocrystals of both rilpivirine (RPV) and cabotegravir, followed by incorporation into separate microneedle delivery systems for application to either side of the face. Following an in vivo study in rats, delivery to the brain was seen for both drugs. For RPV, a Cmax was seen at 21 days of 619.17 ± 73.32 ng/g, above that of recognised plasma IC90 levels, and potentially therapeutically relevant levels were maintained for 28 days. For CAB, a Cmax was seen at 28 days of 478.31 ± 320.86 ng/g, and while below recognised 4IC90 levels, does indicate that therapeutically relevant levels could be achieved by manipulating final microaaray patch size in humans.