Yao Lu

Drug carriers hold significant promise for precision medicine but face persistent challenges in balancing high encapsulation efficiency with structural preservation during active loading. In this study, we present a microelectromechanical system (MEMS)-driven platform that can generate gigahertz (GHz)-frequency acoustic streaming (1.55 GHz) to enable nondestructive, power-tunable drug encapsulation in lipid vesicles. Utilizing DSPE-PEG-modified bilayers with hydrodynamic shear forces, our method achieves transient membrane permeability that preserves membrane integrity while permitting controlled doxorubicin (DOX) influx. We developed the GHz acoustic MEMS platform and applied it to systematically investigate two drug loading strategies: (1) loading DOX into giant unilamellar vesicles (GUVs, >10 μm in diameter) prior to extrusion into small unilamellar vesicles (SUVs, 100 nm) versus (2) direct acoustic loading into pre-formed SUVs. The GUV-first approach demonstrated better performance, achieving 60.04% ± 1.55% encapsulation efficiency (EE%) at 250 mW acoustic power—a 5.93% enhancement over direct SUV loading (54.11% ± 0.72%). Structural analysis via TEM confirmed intact SUV morphology post-loading, while power-dependent EE% analysis showed a linear trend. This work bridges gaps in nanocarrier engineering by optimizing drug loading strategies, aiming to offer a potential drug carrier platform for drug delivery in biomedical treatment in future.

The development of advanced intracellular delivery systems is essential for biopharmaceutical progress, particularly in drug delivery systems, genetic engineering, and cellular therapeutics. While nanovesicles show significant therapeutic potential, challenges remain due to cell membrane barriers and the limitations of endocytosis-mediated pathways. In this study, we introduce an efficient acoustofluidic delivery system that utilizes a gigahertz (GHz)-range bulk acoustic wave (BAW) resonator to generate spatiotemporally controlled acoustic streaming vortices. This system enables rapid (within 10 min) and highly efficient direct cytosolic delivery of nanovesicles by bypassing conventional endosomal entrapment pathways. It effectively delivers both synthetic drug carriers (doxorubicin-loaded small unilamellar vesicles, Dox-SUVs) and biologically active exosomes through GHz-driven hydrodynamic shear forces that induce transient membrane permeability while maintaining cellular viability (>91.5% at 300 mW). Key performances demonstrate 86.5% drug delivery efficiency for Dox-SUVs with near-complete nuclear accumulation, while exosome-mediated delivery exhibits 2.4-fold accelerated migration and 3-fold proliferation enhancement within 24 h. The system's capacity to modulate fluidic shear stresses via BAW power tuning (100-500 mW) allows precise control over membrane permeabilization kinetics and cargo flux. By overcoming endolysosomal sequestration through a noninvasive, physics-driven mechanism, this acoustofluidic approach expands opportunities for next-generation therapeutics, including macromolecular biologic delivery, genome editing, and exosome-mediated intercellular communication.

Rapid protein detection is crucial for medical diagnosis, clinical trials, and drug development but often faces challenges in balancing sensitivity with multiplex detection, low reagent consumption, and a short detection time. In this work, we developed an automated and sensitive electroosmotic digital optofluidics (e-DOF) platform for rapid and label-free protein biomarker quantification in microliter blood samples. The hyperspectral computation reveals nanoscale morphology changes caused by target protein capture, eliminating multifarious enzyme-linked labeling. Electroosmosis-driven molecular circulation accelerates the immuno-hybridization, enhancing sensitivity (with a detection limit of 0.21 nM) and reducing the detection time to 15 min, compared to 2-3 h for a traditional enzyme-linked immunosorbent assay. In multiplex detection of hepatitis A and E IgM in 17 clinical samples, the results were completely consistent with clinical trial outcomes. This e-DOF system presents an automated, rapid, and label-free platform for multiplex detection in microliter samples, highlighting potential applications in clinical diagnosis and immunoassay research.

Facilitated by microelectromechanical systems (MEMS) technology, MEMS speakers or microspeakers have been rapidly developed during the past decade to meet the requirements of the flourishing audio market. With advantages of a small footprint, low cost, and easy assembly, MEMS speakers are drawing extensive attention for potential applications in hearing instruments, portable electronics, and the Internet of Things (IoT). MEMS speakers based on different transduction mechanisms, including piezoelectric, electrodynamic, electrostatic, and thermoacoustic actuation, have been developed and significant progresses have been made in commercialization in the last few years. In this article, the principle and modeling of each MEMS speaker type is briefly introduced first. Then, the development of MEMS speakers is reviewed with key specifications of state-of-the-art MEMS speakers summarized. The advantages and challenges of all four types of MEMS speakers are compared and discussed. New approaches to improve sound pressure levels (SPLs) of MEMS speakers are also proposed. Finally, the remaining challenges and outlook of MEMS speakers are given.