Ultrasonic Interfacial Engineering of Red Phosphorous-Metal for Eradicating MRSA Infection Effectively

Sonodynamic therapy (SDT) is considered to be a potential treatment for various diseases including cancers and bacterial infections due to its deep penetration ability and biosafety, but its SDT efficiency is limited by the hypoxia environment of deep tissues. This study proposes creating a potential solution, sonothermal therapy, by developing the ultrasonic interfacial engineering of metal-red phosphorus (RP), which has an obviously improved sonothermal ability of more than 20 degrees C elevation under 25 min of continuous ultrasound (US) excitation as compared to metal alone. The underlying mechanism is that the mechanical energy of the US activates the motion of the interfacial electrons. US-induced electron motion in the RP can efficiently transfer the US energy into phonons in the forms of heat and lattice vibrations, resulting in a stronger US absorption of metal-RP. Unlike the nonspecific heating of the cavitation effect induced by US, titanium-RP can be heated in situ when the US penetrates through 2.5 cm of pork tissue. In addition, through a sonothermal treatment in vivo, bone infection induced by multidrug-resistant Staphylococcus aureus (MRSA) is successfully eliminated in under 20 min of US without tissue damage. This work provides a new strategy for combating MRSA by strong sonothermal therapy through US interfacial engineering.

Automated summary

Sonodynamic therapy (SDT) is limited by the hypoxia environment of deep tissues, but a potential solution, sonothermal therapy, has been proposed in this study. By developing ultrasonic interfacial engineering of metal-red phosphorus (RP), the sonothermal ability is significantly improved. The mechanical energy of ultrasound activates the motion of interfacial electrons to efficiently transfer the energy into phonons, resulting in stronger ultrasound absorption of metal-RP.