The application of microneedle-based biosensors in the diagnosis and monitoring of chronic diseases: progress of materials and design

The chronic diseases have become widespread and their detrimental influence on healthcare system is a global concern. Chronic diseases which are considered as noncommunicable diseases (NCDs) include various conditions including cardiovascular diseases, diabetes, cancer, and respiratory disorders [۱]. Enormous amount of psychological pressure is imposed on patients who are diagnosed with chronic diseases in addition to substantial financial burden. Consequently, the early diagnosis and continuous monitoring of disease with precise treatment procedure is of great importance for improving patients' lives and preventing disease progression [۲] The real-time monitoring for in vivo analytes including biomarkers and drugs by sensors is of great importance for disease diagnosis and management, as well as in personalized medicine [۳, ۴]. The term "microneedle-based biosensor" is described as a medical analytical tool with a thin and sharp tip that can be used for detecting and reporting the desired analyte in biofluids available under the human skin. The microneedle-based biosensor is applied to insert the needle which is composed of a sensing function through the outermost layer of the skin to reach a biofluid available under out skin [۵-۸]. Minimally or noninvasively accessible bodily fluids, including interstitial fluid (ISF), urine, and saliva, are being investigated. Among them, ISF has a rich biomarker profile and analytes which is of great importance clinically [۹].Microneedles(MNS) are usually designed to have a length within the range of ۵۰۰ μm to ۲۰۰۰ μm, for having an adequate amount of access to the ISF of the skin [۱۰, ۱۱]. The detection of biomarkers are done by different methods including fluorescence, optical and electrochemical techniques that are integrated into the MN system [۹]. Specifically, electrochemical technique depends on the oxidation/reduction reaction of the desired chemical into an electrical signal which provides quantitative analysis [۱۲].A rapid response and sufficient stability could be achieved by this method which makes it suitable for the employment in MN sensing systems [۱۳]. Microneedles are generally classified into four categories which includes solid and coated, hollow and dissolving MNs. Solid MNs are mainly fabricated from materials like silicon, ceramic and metals including gold, nickel, titanium and non-degradable polymers which have high resilience to physically make pores through the skin and subsequently improving the drug permeability at the site of application [۱۴]. For the fabrication of dissolving MNs, the encapsulated drug-loaded biodegradable materials, including polyesters, polyvinyl and carbohydrates, are used [۱۴]. The hypodermic delivery of high molecular weight compounds including nucleic acids, antibodies, and proteins in large quantities could be done by the Hollow MNs. The size of Hollow MNs could be altered for managing the release rate and pressure of the compounds. Hollow MNs are fabricated from metals including gold, titanium, stainless steel, ceramic, and other non-degradable polymers [۱۴, ۱۵]. The geometry and mechanical properties of MNs-based biosensors are of great importance. The sharpness and length of needles and the stiffness and viscoelasticity should be considered, respectively. Recently, significant attention has been given to the development of Microneedle-based biosensor for the real-time monitoring of chronic diseases including cancer, diabetes, and cystic fibrosis by penetrating through the epithelial tissue for capturing and analysing the vital biomarkers [۱۶]. The main aim of this review is to describe different types of microneedles, materials and design criteria and most importantly, their integration with electrochemical biosensors. Moreover, the potential application of the Microneedle-based biosensors in the diagnosis and monitoring of chronic diseases is highlighted. Finally, it should be noted that despite the huge advancements in the development of MNs-based biosensors several challenges still remain for the use in clinical settings.

کلیدواژه ها:

Biosensors ، Chronic diseases ، Diagnosis and monitoring ، Microneedles