Sustainable Development Goals

Abstract/Objectives

This research proposes an innovative strategy that integrates Acoustic Vortex Tweezers (AVT) with on-resonance ultrasound to significantly enhance targeted drug delivery. By using AVT, drug-loaded microbubbles are acoustically manipulated and clustered into controllable aggregates. When these microbubble clusters are stimulated at their resonance frequency (~100 kHz) with low-intensity ultrasound, they undergo pronounced cavitation dynamics that trigger efficient payload release. Experimental results demonstrate that this approach achieves up to ~93 % drug release efficiency, outperforming conventional high-frequency ultrasound and AVT alone. The enhanced release is attributed to synergistic mechanical effects driven by the resonant cavitation of clustered microbubbles, which amplifies local acoustic energy deposition while minimizing thermal exposure. Additionally, the inertial cavitation dose (ICD) correlates strongly with release efficiency, suggesting a robust acoustic parameter for real-time monitoring and control. This technique offers high penetration depth, spatiotemporal precision, and reduced risk of collateral tissue damage. It holds promise for applications in precision therapy for cancer, cardiovascular diseases, and other conditions requiring localized, sustained drug administration. By advancing ultrasound-mediated pharmacological delivery with greater efficacy and safety, this work contributes to the development of sustainable biomedical technologies aligned with precision medicine goals.

Results/Contributions

This study demonstrates a novel ultrasound-mediated platform that significantly improves the efficiency and control of targeted drug delivery by combining Acoustic Vortex Tweezers (AVT) with resonant ultrasound stimulation. The central innovation lies in the acoustic aggregation of drug-loaded microbubbles into dense clusters using AVT under flowing conditions. These clusters act as focal loci for enhanced mechanical interaction when stimulated at their resonance frequency (~100 kHz). Unlike traditional high-frequency ultrasound that primarily induces thermal effects, low-frequency resonant stimulation drives intense cavitation activity around the clustered microbubbles, facilitating efficient payload release while mitigating thermal risks.


Quantitatively, the clustered microbubbles exposed to resonant ultrasound achieved approximately 93 % drug release efficiency, markedly higher than that obtained with either AVT alone or conventional high-frequency ultrasound protocols. This improvement is supported by strong correlation between inertial cavitation dose (ICD) and release performance (R² ≈ 0.78), indicating that cavitation intensity can serve as a reliable physical indicator for optimizing and monitoring therapeutic delivery in real time.

Methodologically, the research deployed synchronized optical and acoustic measurement systems to characterize the dynamics of microbubble aggregation and release behavior under varying acoustic pressures and flow conditions. These measurements elucidated the dependency of release efficiency on cluster size, resonance matching, and acoustic pressure levels. The results show that resonant stimulation not only increases payload release but does so under lower energy conditions, which is critical for reducing off-target effects and ensuring patient safety. The approach also preserved the structural integrity of surrounding media, highlighting its potential for minimally invasive clinical translation.


The contributions of this work extend across scientific, technological, and translational domains:


  1. Enhanced Delivery Efficiency — Demonstrated a significant increase in drug payload release compared to existing ultrasound-based techniques, enabling more effective localized therapy.
  2. Improved Safety Profile — Utilized low-intensity, low-frequency ultrasound that reduces thermal and mechanical damage to adjacent tissues, aligning with clinical safety standards.
  3. Real-Time Monitoring Capability — Identified inertial cavitation dose (ICD) as a predictive parameter for controlled release, enabling acoustic feedback control strategies.
  4. Multidisciplinary Integration — Combined principles from acoustics, microbubble physics, biomedical engineering, and therapeutic delivery, fostering cross-disciplinary innovation.
  5. Clinical Translation Potential — The strategy’s compatibility with existing ultrasound hardware and itsnon-invasive nature support future adaptation for precision therapeutic applications such as oncology, targeted vascular therapies, and site-specific drug administration.


Overall, this research establishes a scalable and controllable platform for sustainable, ultrasound-assisted drug delivery, providing a foundation for future clinical and commercial development in precision medicine.


Keywords

Acoustic Vortex TweezersMicrobubble ClusteringUltrasound-enhanced Drug DeliveryCavitation DynamicsOn-Resonance UltrasoundTargeted TherapeuticsPrecision Medicine

References

Contact Information

葉秩光
ckyeh@mx.nthu.edu.tw