Guowu Ma

Alzheimer’s disease (AD) early screening requires non-invasive, high-sensitivity detection of low-abundance biomarkers in complex biofluids like saliva. In this study, we present a miniaturized, silicon-based electrochemical sensor for sequential detection of two AD salivary biomarkers, lactoferrin (Lf) and amyloid β-protein 1-42 (Aβ_1-42), on a single reusable electrode. The sensor features a three-electrode system fabricated by sputter-coating a quartz substrate with gold (Au) sensing electrodes, which are further modified with gold nanoparticles (AuNPs) to form 3D dendritic structures that enhance surface area and electron transfer. To improve specificity, immunomagnetic beads (MBs) are employed to selectively capture and isolate target biomarkers from saliva samples. These MB–biomarker complexes are introduced into a polydimethylsiloxane chamber aligned with Au sensing electrodes, where a detachable magnet localizes the complexes onto the electrode surface to amplify redox signals. The AuNPs/MBs sensor achieves detection limits of 2 μg/mL for Lf and 0.1 pg/mL for Aβ_1-42, outperforming commercial ELISA kits (37.5 pg/mL for Aβ_1-42) and covering physiological salivary concentrations. After the MBs capture the biomarkers, the sensor can output the result within one minute. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements confirm enhanced electron transfer kinetics on AuNP-decorated surfaces, while linear correlations (R² > 0.95) validate quantitative accuracy across biomarker ranges. The compact and integrated design eliminates reliance on bulky instrumentation and enables user-friendly operation, establishing a promising platform for portable, cost-effective AD screening and monitoring.

The development of osteogenic biomaterials relies on updates in research methodologies. Establishing reasonable modes is the basis for obtaining reliable experimental conclusions. With the advancement in bone immunology, osteoimmunomodulatory properties have become one of the crucial indexes for evaluating osteogenic biomaterials. Summarizing the current models of bone immunomodulation is beneficial for optimizing experimental protocols and promoting the clinical application of osteogenic biomaterials. In this review, we introduced the crosstalk between the skeletal system and the immune system, in particular, the roles of different immune cells in the process of bone regeneration. Moreover, the mechanisms of osteogenic biomaterials in regulating the osteoimmune microenvironment were analyzed, followed by summarizing the benefits and limitations of current osteoimmunomodulation models in evaluating osteogenic biomaterials. Finally, we discussed the expected future directions of the applications of osteoimmunomodulation models.