Hydrogel Microneedles Extracting Exosomes for Early Detection of Colorectal Cancer

Nanocomposite hydrogel microneedles: a theranostic toolbox for personalized medicine

Due to the severity and high prevalence of cancer, as well as its complex pathological condition, new strategies for cancer treatment and diagnostics are required. As such, it is important to design a toolbox that integrates multiple functions on a single smart platform. Theranostic hydrogels offer an innovative and personalized method to tackle cancer while also considering patient comfort, thereby facilitating future implementation and translation to the clinic. In terms of theranostic systems used in cancer therapy, nanoparticles are widely used as diagnostic and therapeutic tools. Nanoparticles can achieve systemic circulation, evade host defenses, and deliver drugs and signaling agents at the targeted site, to diagnose and treat the disease at a cellular and molecular level. In this context, hydrogel microneedles have a high potential for multifunctional operation in medical devices, while avoiding the complications associated with the systemic delivery of therapeutics. Compared with oral administration and subcutaneous injection, microneedles offer advantages such as better patient compliance, faster onset of action, and improved permeability and efficacy. In addition, they comprise highly biocompatible polymers with excellent degradability and tunable properties. Nanoparticles and microneedles thus offer the possibility to expand the theranostic potential through combined synergistic use of their respective features. We review herein recent advances concerning processing methods and material requirements within the realm of hydrogel microneedles as theranostic platforms, various approaches toward cancer therapy, and the incorporation of nanoparticles for added functionality.

Hydrogel-based technologies in liquid biopsy for the detection of circulating clinical markers: challenges and prospects

Liquid biopsy, which promises noninvasive detection of tumor-derived material, has recently been highlighted because of its potential to lead us to an era of precision medicine. However, its development has encountered challenges owing to the extremely low frequency and low purity of circulating tumor markers, such as circulating tumor cells (CTCs), circulating exosomes, and circulating tumor nucleic acids (ctNAs). Much effort has been made to overcome this limitation over the last decade, and an increasing number of studies have shown interest in the special characteristics of hydrogels. This hydrophilic and biocompatible polymeric network, which absorbs a large amount of water, can aid in the isolation, protection, and analysis of these low-abundance and short-lived circulating biomarkers. The role of hydrogels in liquid biopsy is extensive and ranges from enrichment to encapsulation. This review provides an overview of hydrogel-based technologies to pave the way in liquid biopsy.

A swellable hydrogel microneedle based on cerium-metal organic frame composite nanozyme for detection of biomarkers

Skin interstitial fluid (ISF) has been an alternative source in the field of biomarkers analysis. This work developed swellable hydrogel microneedles (MNs) composed of polyvinyl alcohol and sodium alginate by chemical crosslinking (PVA/SA). Here, PVA/SA was firstly used to fabricate hydrogel MNs, achieving a swellable ratio of 150 % and a rapid extraction of 6.4 mg ISF in 15 min. To replace expensive and non-reusable test kits, hydrogel MNs based on composite nanozyme with high oxidase-like activity were successfully developed to recover and detect biomarkers. The nanozyme was composed of MnO2-modified mixed valence cerium-metal organic frame (MCM). MCM was characterized by multiple techniques to further confirm its composition and structure. MCM combined with the reduction reaction of glutathione (GSH) with oxidized substrate to achieve a colorimetric GSH detection, which had a detection limit (LOD, 0.36 μM) of GSH. The hydrogel MNs based on MCM (MCM-MNs) were firstly applied to the rapid detection of GSH in ISF. All in all, this method combines the advantages of nanozyme and hydrogel MNs to achieve a timely and minimally invasive analysis, which provides a new dimension for the in vivo detection of GSH by skin ISF and holds great implications in biomedical and bioanalysis fields.

Microneedle systems: cell, exosome, and nucleic acid based strategies

Cells, exosomes, and nucleic acids play crucial roles in biomedical engineering, holding substantial clinical potential. However, their utility is often hindered by various drawbacks, including cellular immunogenicity, and instability of exosomes and nucleic acids. In recent years, microneedle (MN) technology has revolutionized drug delivery by offering minimal invasiveness and remarkable versatility. MN has emerged as an ideal platform for the extraction, storage, and delivery of these biological components. This review presents a comprehensive overview of the historical progression and recent advances in the field of MN. Specifically, it highlights the current applications of cell-, exosome-, and nucleic acid-based MN systems, while presenting prevailing research challenges. Additionally, the review provides insights into the prospects of MN in this area, aiming to provide new ideas for researchers and facilitate the clinical translation of MN technology.

The Progress in the Application of Dissolving Microneedles in Biomedicine

In recent years, microneedle technology has been widely used for the transdermal delivery of substances, showing improvements in drug delivery effects with the advantages of minimally invasive, painless, and convenient operation. With the development of nano- and electrochemical technology, different types of microneedles are increasingly being used in other biomedical fields. Recent research progress shows that dissolving microneedles have achieved remarkable results in the fields of dermatological treatment, disease diagnosis and monitoring, and vaccine delivery, and they have a wide range of application prospects in various biomedical fields, showing their great potential as a form of clinical treatment. This review mainly focuses on dissolving microneedles, summarizing the latest research progress in various biomedical fields, providing inspiration for the subsequent intelligent and commercial development of dissolving microneedles, and providing better solutions for clinical treatment.