Piezoelectric actuation combined with ultrasound for enhancing drug delivery in gastric mucosa phantom in vitro

Abstract

In recent years, treatments for gastrointestinal malignant tumors have attracted a lot of attention. However, due to size limitations and the working environment of gastrointestinal peristalsis, traditional treatment methods have poor efficacy. Herein, we proposed a novel drug release method of piezoelectric actuation combined with ultrasound in the endoscope biopsy channel. A bidirectional piezoelectric actuator was manufactured and inserted into the endoscope with an ultrasonic transducer, adjusting the distance between the transducer and the lesion. A gastric mucosa phantom was fabricated and a finite element (FE) model was established for ultrasound thermal calculation. For enhancing the drug release rate, a pulse-echo method was conducted using a Laboratory Virtual Instrument Engineering Workbench (LabVIEW) program for real-time monitoring and feedback. The results of FEM calculations show that the temperature in the phantom can reach the melting-phase transition temperature of the TSL (41 ± 1 °C). The drug release rate can increase from 2.2 × 10−4 mg min−1 to 39.2 × 10−4 mg min−1 with our actuator, the latter is nearly 18 times the former. Furthermore, the drug release rate can be increased to a maximum value of 45.8 × 10−4 mg min−1 by optimizing the driving parameter of our actuator. Therefore, our method has a bright application in targeted drug delivery of major gastrointestinal diseases in the future.