Hyaluronic acid (HA) is a glycosaminoglycan that plays many roles in health and disease and is a key biomarker of certain cancers. Therefore, its detection at an early stage, by histochemical methods, is of importance. However, intracellular HA can be masked by other HA-binding macromolecules, rendering its visualization somehow problematic. We show that fluorescent molecularly imprinted polymer nanogels (MIP-NPs), can localize and detect intracellular HA. MIP-NPs were synthesized by solid-phase synthesis on glass beads (GBs). GBs were functionalized with terminal alkyne groups on which an azide derivative of the template molecule glucuronic acid was immobilized via click chemistry. Immobilization via the anomeric carbon left the template’s carboxyl moiety free to enable strong stoichiometric electrostatic interactions with a benzamidine-based functional monomer, to confer selective recognition to the MIP-NPs. Due to the two-point orientation of the template, the resulting MIP-NPs were endowed with improved binding site homogeneity and specificity, reminiscent of monoclonal antibodies. These synthetic antibodies were then applied for probing and staining HA, of which glucuronic acid is a substructure (epitope), on human epidermal cells. Their excellent sensitivity, small size and water compatibility, enabled the MIP-NPs to visualize HA, as evidenced by confocal fluorescence micrographs.
Cancer is one of the leading causes of mortality worldwide, because of the lack of accurate diagnostic tools for the early stages of cancer. Thus, early diagnosis, which provides important information for a timely therapy of cancer, is of great significance for controlling the development of the disease and the proliferation of cancer cells and for improving the survival rates of patients. To achieve the goals of early diagnosis and timely therapy of cancer, DNA nanotechnology may be effective, since it has emerged as a valid technique for the fabrication of various nanoscale structures and devices. The resultant DNA-based nanoscale structures and devices show extraordinary performance in cancer diagnosis, owing to their predictable secondary structures, small sizes, and high biocompatibility and programmability. In particular, the rapid development of DNA nanotechnologies, such as molecular assembly technologies, endows DNA-based nanomaterials with more functionalization and intellectualization. Here, we summarize recent progress made in the development of DNA nanotechnology for the fabrication of functional and intelligent nanomaterials and highlight the prospects of this technology in cancer diagnosis and therapy.
13 February 2019 in ACS Applied Materials & Interfaces
Biosensors are a class of smart devices fabricated for target analyte detection. A biosensor is commonly made of three basic components: a specific bioreceptor, a physicochemical transducer, and a signal processing device. The bioreceptor part features one of the more crucial technologies of a biosensor to perform specific detection of analytes. They commonly make use of various molecular recognition elements, such as enzymes, natural receptors, antibodies, nucleic acid aptamers, and even synthetic receptors. Then, the molecular recognition events of these bioreceptors can be translated into readable signals in various forms like electrochemical, optical, piezo/pyro electric, etc. Finally, these signals are mathematically processed for quantitative analysis. Nowadays, the great advances in biomimetic materials, in particular the synthetic receptors based on molecularly imprinted polymers (MIPs), promote tremendous development of biosensors. Integration of this field with artificial intelligence enables emerging design of advanced biosensors, which has moved from concept to implementation, meanwhile facing new opportunities and challenges. With no doubt, bioreceptor innovation based on molecular imprinting is an emerging driving force for biosensors development. In this review paper, we provide an overview of MIP‐based biosensors, and also their challenges and opportunities moving forward toward wearable devices are discussed.
21 August 2021 in Angewandte Chemie International Edition