Advances in the Formulations of Microneedles for Manifold Biomedical Applications

Abstract

These MN platforms have been intensively explored for transdermal drug delivery in the treatment of both local and systemic diseases. [1c,12] They function as carriers for small molecular drugs, [13] peptides and proteins (e.g., insulin, vaccines, and antibodies), [8a,14] oligonucleotides, [11d] and nanomedicines [10a,b] and deliver them into peripheral tissues like skin, eyes, mouth, vascular wall, vagina etc. [15] Recently, MNs also receive attention from medical diagnosis and health monitoring, as they can easily access skin interstitial fluid (ISF) that is formed by blood transcapillary filtration and contains numerous biomarkers of clinical interest. [16] They can either directly sample ISF for postanalysis, [9e,11b,17] or integrate with sensing components for in situ real-time monitoring. [18] This article summarizes the recent advances in the MN field including the design, fabrication, and biomedical applications (Figure 1). The challenges and future perspectives are also discussed.

Hydrogel-Based Technologies for the Diagnosis of Skin Pathology

“…Moreover, while animal testing typically involves the single disease model, real human diagnosis is often implicated with coexisting diseases and/or widely diverse human behaviors. Skin properties of individual patient can somewhat differ from other patients bearing the same disease [59]. To this end, biofabrication (i.e., 3D bioprinting and electrospinning) of in vitro skin models employing patient-isolated cells provides a better avenue to recapitulate the physio-/pathophysiology of human skin in a personalized manner [161].…”

“…In recent years, hydrogel applications as POC biosensors have risen significantly, including for several pathological skin conditions. Given its swellable property, hydrogels can facilitate extraction of biofluids (e.g., wound exudate and interstitial fluid/ISF) implicated in various pathological skin conditions [59]. Formed as microparticles or dressing patches, hydrogels enable collection and analysis of open wound exudates [60].…”

Smart Microneedles for Therapy and Diagnosis

“…Much progress has been made including the popularization of biocompatible hydrogel microneedles, the improvement of microneedle fabrication strategies, and the exploration in clinical applications of microneedles. In the meanwhile, some reviews summarizing the classification of microneedles, their fabrication techniques, and applications in detection and drug delivery have been presented [ 119 – 121 ]. In recent years, microneedles have been imparted with novel and intriguing features such as skin adhesion, rapid dissolvability, separability, responsive ability, antibacteria, and explosive capacity to meet the complex requirements in actual use.…”

Intradermal delivery of receptor‐binding domain of SARS‐CoV‐2 spike protein with dissolvable microneedles to induce humoral and cellular responses in mice

“…The MN patch was made through micro-molding. 20,21 Firstly, we prepared HA solution with distilled water. There are three types of medical grade HA (i.e., 48, 300, and 1100 K).…”