Abstract Accurate detection of tumor-associated biomarkers from different molecular classes is important for early diagnosis and disease monitoring. However, the development of a single sensing strategy that can be adapted to nucleic acids, proteins, and small molecules remains challenging because of their distinct recognition mechanisms and physicochemical properties. In this work, we developed a modular biosensing strategy based on a hairpin adapter-initiated dual catalytic hairpin assembly (dCHA), for the sensitive and separate detection of representative biomarkers from three molecular classes using a unified signal transduction framework. In this design, target-specific recognition events were converted into a unified intermediate DNA trigger, thereby coupling different recognition modules with a common nucleic acid amplification module. As proof-of-concept targets, miRNA-183 (miR-183), prostate-specific antigen (PSA), and sarcosine were selected to represent nucleic acid, protein, and small-molecule biomarkers, respectively. The proposed system showed sensitive analytical performance, with limits of detection of 0.070 nM for miR-183, 0.48 ng/mL for PSA, and 0.26 nM for sarcosine, which are comparable to or within the range of gold-standard methods. In addition, recovery experiments in spiked human urine samples demonstrated the preliminary applicability of the assay in a complex biological matrix. This study provides a modular signal transduction strategy for detecting representative biomarkers of different molecular types and may offer a useful basis for further development of multiplexed and clinically validated biosensing systems.
Abstract Multi-stimuli-responsive biodegradable polymeric nanoassemblies with high encapsulation ability, micellar stability, and programmed intracellular drug release are highly attractive for efficient cancer therapy. Herein, an amphiphilic diblock copolymer responsive to three endogenous stimuli of a cancer cell is synthesized using temperature-responsive poly(N-vinylcaprolactam) as a macroinitiator for the ring-opening polymerization of chloroalkyl-substituted ε-caprolactone. Phenyl and triazole rings are incorporated in the side chain to link a redox-responsive disulfide group to a hydrophobic block using click chemistry. The diblock copolymer self-assembles in aqueous medium into spherical micelles with an average hydrodynamic diameter of 140–150 nm. High dye encapsulation efficiency and stability are verified by fluorescence resonance energy transfer and isothermal titration calorimetry studies. Copolymer nanoassemblies display ill-defined aggregates at tumor-relevant temperatures (40–43 °C), glutathione-induced swelling, and esterase-mediated complete micellar disassembly. Combined effect of triple stimuli on drug release is observed compared to the release in response to individual stimuli. The diblock copolymer shows excellent biocompatibility with MCF-7 and MDA-MB-231 cancer cells, and DOX-loaded copolymer nanoassemblies show cytotoxicity toward the cancer cells, augmented by low IC50 values (6.37 and 4.58 μg/mL). Cellular uptake and time-dependent drug release in cancer cells are demonstrated.
Abstract Type 2 diabetes mellitus demands coordinated control of fasting and postprandial glycemia, and current clinical rapid-acting insulin aspart (IAsp) suffers from short action duration and hypoglycemia-related risks. We describe a glucose-sensitive insulin delivery system based on rigid amphiphilic methoxy poly(ethylene glycol)-polysalicylate (mPEG-PSA) copolymers synthesized by controlled ring-opening polymerization of salicylic acid O-carboxyanhydride, with a structure substantially different from conventional aliphatic polyesters. The 100–150 nm nanoparticles possessed favorable colloidal stability, ∼85% encapsulation efficiency and ∼20% drug loading, and IAsp bioactivity was well preserved. In vitro release followed glucose-dependent kinetics tuned by PSA hydrophobicity. In streptozotocin-induced diabetic mice, IAsp@mPEG-PSA restored euglycemia within 0.5 h and maintained normoglycemia for up to 10 h without hypoglycemia, outperforming free IAsp and mPEG-PLA formulations in this animal model. The nanosystem realized glucose-activated on-demand insulin release to suppress repeated glucose spikes, accomplishing combined postprandial and basal glycemic regulation in rodents. This study presents mPEG-PSA as a promising polymeric candidate for glucose-responsive insulin delivery.
