Sonodynamic therapy exciting the herbal nanocomposite with spider-web-like effect to combat otitis media.

Otitis media, mainly caused by bacteria, is prevalent in young children and can cause hearing loss and growth retardation. Antibiotics are the most widely utilized treatment for otitis media, however, they can cause drug resistance and harmful side effects. In this study, we reported an antibacterial nanocomposite in combination with sonodynamic therapy that consists of herbal antibacterial agents such as Curcumin (CUR) and Tanshinone IIA (TSIIA), as well as Chitosan (CS), for the treatment of acute otitis media. CUR/TSIIA/CS nanocomposite (NC) with ultrasonic irradiation demonstrated that it could eliminate Staphylococcus aureus. In vivo experiments revealed that NC-mediated sonodynamic therapy had excellent antibacterial and anti-inflammatory activity, displaying a consistent performance comparable to ofloxacin. The therapeutic efficiency was attributed to capturing bacteria through spider-web-like effect and destroying bacteria through the reactive oxygen species generated under ultrasonic irradiation. Significantly, NC did not induce bacterial resistance and showed good biocompatibility. This study provides a novel strategy to develop an ultrasound-assisted nanocomposite with an enhanced antibacterial effect. Further, it unlocks new doors for the substitute of antibiotics to combat otitis media by establishing efficient therapeutic systems.

Self temperature regulation of photothermal therapy by laser-shared photoacoustic feedback.

This article describes a laser-shared photothermal system that achieves tight temperature regulation by frequency-domain photoacoustic (FD-PA) feedback. To this end, a continuous-wave laser system was designed with arbitrarily modulatable laser intensity. And, by fast alternating in the time domain between a constant laser intensity for photothermal heating and a modulated laser intensity for FD-PA temperature measurement, photothermal temperature variations are captured by FD-PA in real time. A proportional-integral-derivative (PID) controller monitors the feedback from FD-PA measurements and controls photothermal heating dose accordingly, thus stabilizing the temperature at preset values. The proposed system is demonstrated to achieve ultrafast temperature measurement at a 4 kHz rate, and with proper averaging, the measurement and regulation accuracy are 0.75 deg and 0.9 deg respectively.

Focused Magnetic Resonance Coupling Coils for Electromagnetic Therapy Applications.

This paper presents the design and construction of a pair of figure-of-eight coils, coupled by magnetic resonance coupling (MRC), which could generate (150 V/m per Ampere) electric field at the focal points for electromagnetic therapy related applications. The E field generated at the targeted site would be significantly enhanced under the same amount of current flowing through the MRC figure-of-eight coils compared to normal coils, due to the superposition of E field contributed by the coils. Furthermore, the MRC figure-of-eight coil is designed and the results are verified in theory, simulation, and experiments. In the ex vivo tissue measurement, 35% current and 82% ohmic power improvements were observed. Since it can enhance the current and ohmic power, the MRC figure-of-eight coils are promising solutions for electromagnetic therapy applications. The potential applications of the coils include noninvasive radio frequency (RF) stimulation, thermoacoustic imaging, electromagnetic field therapies, and RF ablation, etc.