Enhancement of acoustic cavitation using chitosan nanoparticle-shelled composites

Ultrasound cavitation finds diverse applications across biomedical engineering, chemical processes, and industrial systems. Its effects significantly influence the performance of ultrasound imaging and targeted drug delivery. Although microbubbles have been found to enhance cavitation activity, their effect is practically insufficient. To enhance cavitation activity, we introduce a composite structure utilizing chitosan nanoparticles as a stabilizing shell. The relationship between chitosan nanoparticle size and the initial concentrations of chitosan and sodium tripolyphosphate linker is systematically analyzed. The cavitation effect associated with these chitosan nanoparticle-shelled composites is assessed using iodide dosimetry under ultrasonic irradiation at 20 kHz. Composites encapsulated by a positively charged chitosan nanoparticle shell, measuring 23 nm in size, demonstrate significant improvements in hydroxyl radical generation compared to untreated samples, indicating enhanced acoustic cavitation. These findings highlight the potential of combining chitosan nanoparticles with microbubbles for versatile applications ranging from ultrasound imaging to drug delivery.