Microbubble-Enhanced\nTransdermal Drug Delivery Sonoelectric\nPatch

Transdermal drug delivery systems are highly appealing\nas a convenient\ndrug delivery manner applicable to a wide variety of drugs. While\nmost delivery relies on only passive diffusion and suffers low transdermal\nefficiencies. Ultrasound motivation promotes drug transdermal penetration\nbut still calls for improvement, because only a thin proportion of\nthe ultrasound energy is applied on the drug delivery patch and most\nultrasound energy is wasted in deeper portions of biotissues. In this\nwork, we develop a transdermal patch for enhanced drug delivery. The\ncombination of microsized air pockets and the piezoelectric soft structure\nenable the conversion of an intended proportion of ultrasound energy\ninto electric energy. The intensified drug flow and synergistic ultrasound\npressure and electric field function simultaneously to enhance drug\ntransdermal delivery. The delivery efficacy is related to the power\nof the ultrasound motivation, the size of the microscopic air pockets,\nand the chemical structure of the drug molecules. The temperature\nof the patch within the delivery process remains in the safe range,\nand the mild temperature elevation causes color changes of the thermochromic\npatch, used to indicate effective ultrasound–patch matching.\nA model delivery patch for pain release is constructed, and animal\nexperiments indicate that the drug blood concentrations are 100% higher\nthan the delivery using only ultrasound and even more remarkably enhanced\nwhen compared to only electric-field-motivated delivery or static\ndelivery without external motivations.