Bioimaging of Dissolvable Microneedle Arrays: Challenges and Opportunities

Abstract

The emergence of microneedle arrays (MNAs) as a novel, simple, and minimally invasive administration approach largely addresses the challenges of traditional drug delivery. In particular, the dissolvable MNAs act as a promising, multifarious, and well-controlled platform for micro-nanotransport in medical research and cosmetic formulation applications. The effective delivery mostly depends on the behavior of the MNAs penetrated into the body, and accurate assessment is urgently needed. Advanced imaging technologies offer high sensitivity and resolution visualization of cross-scale, multidimensional, and multiparameter information, which can be used as an important aid for the evaluation and development of new MNAs. The combination of MNA technology and imaging can generate considerable new knowledge in a cost-effective manner with regards to the pharmacokinetics and bioavailability of active substances for the treatment of various diseases. In addition, noninvasive imaging techniques allow rapid, receptive assessment of transdermal penetration and drug deposition in various tissues, which could greatly facilitate the translation of experimental MNAs into clinical application. Relying on the recent promising development of bioimaging, this review is aimed at summarizing the current status, challenges, and future perspective on in vivo assessment of MNA drug delivery by various imaging technologies.

Dissolving microneedles for effective and painless intradermal drug delivery in various skin conditions: A systematic review

“…Microneedle patches are capable of penetrating the skin and supply substances in a controlled, efficient and non-to minimally-invasive pain free manner. 7,34 DMN avoid the significant first pass effect which limits the biological availability in enteral administration.…”

Porous Microneedles for Therapy and Diagnosis: Fabrication and Challenges

“…MNs are being researched and used in a variety of fields as a convenient, rapid, and novel transdermal drug delivery system, but there are currently very few commercially available MNs products. The reason for this could be a lack of standardized tests and equipment used to demonstrate the mechanical strength and insertion ability of MNs, leaving researchers to judge the quality of MNs using their own individual criteria, so the establishment of a series of normative standards for controlling MNs quality is essential and urgent to ensure the effectiveness of MNs clinical applications . As a special type of MNs, in addition to the length, tip, base diameter, shape, material, and spacing of the MNs, the pore structure of the porous MNs themselves (e.g., porosity and pore size) can have an impact on the mechanical strength of the MNs, drug loading and release, and ISF extraction.…”

Engineering metastructures for the full control of flexural waves

“…In particular, researchers have studied the wave modulation of pillared metastructures by combining the spring-mass scatterer model and multiple scattering theory, and further characterized the elastic topological vortex modes [22], which provide new ideas for theory-based designing topological vortex modes. The highly localized topological vortex modes enable metastructure functional devices to generate high energy density at the set position and frequency, which can be used to practically design functional devices such as piezoelectric energy harvesting, biosensing [139], bioimaging [140,141] and communication on-chip [142]. The spring scatterer model of the mass-thin-neck configuration can be well described by the multiple scattering theory [22], but the difficulties in the micro/nano miniaturized manufacturing of compact integrated functional devices urge to be solved.…”

“…In the previous chapter, we achieved the functional application of energy harvesting via topological vortex modes [23]. The high energy density resulting from the localization enhancement associated with this topological vortex mode may be used for biosensing [139], bioimaging [140,141] and on-chip communication [142]. The mass-neck spring resonators can be well described with the multiple scattering theory [22,23], however, they can be hardly achieved with micro/nano fabrication methods for compact and integrated devices.…”