Piezoelectric Single Crystal Ultrasonic Transducer for Endoscopic Drug Release in Gastric Mucosa

Miniaturized therapeutic systems for ultrasound-modulated drug delivery to the central and peripheral nervous system

Ultrasound is a promising technology to address challenges in drug delivery, including limited drug penetration across physiological barriers and ineffective targeting. Here we provide an overview of the significant advances made in recent years in overcoming technical and pharmacological barriers using ultrasound-assisted drug delivery to the central and peripheral nervous system. We commence by exploring the fundamental principles of ultrasound physics and its interaction with tissue. The mechanisms of ultrasonic-enhanced drug delivery are examined, as well as the relevant tissue barriers. We highlight drug transport through such tissue barriers utilizing insonation alone, in combination with ultrasound contrast agents (e.g., microbubbles), and through innovative particulate drug delivery systems. Furthermore, we review advances in systems and devices for providing therapeutic ultrasound, as their practicality and accessibility are crucial for clinical application.

Piezoelectric Nanomaterials Activated by Ultrasound in Disease Treatment

Electric stimulation has been used in changing the morphology, status, membrane permeability, and life cycle of cells to treat certain diseases such as trauma, degenerative disease, tumor, and infection. To minimize the side effects of invasive electric stimulation, recent studies attempt to apply ultrasound to control the piezoelectric effect of nano piezoelectric material. This method not only generates an electric field but also utilizes the benefits of ultrasound such as non-invasive and mechanical effects. In this review, important elements in the system, piezoelectricity nanomaterial and ultrasound, are first analyzed. Then, we summarize recent studies categorized into five kinds, nervous system diseases treatment, musculoskeletal tissues treatment, cancer treatment, anti-bacteria therapy, and others, to prove two main mechanics under activated piezoelectricity: one is biological change on a cellular level, the other is a piezo-chemical reaction. However, there are still technical problems to be solved and regulation processes to be completed before widespread use. The core problems include how to accurately measure piezoelectricity properties, how to concisely control electricity release through complex energy transfer processes, and a deeper understanding of related bioeffects. If these problems are conquered in the future, piezoelectric nanomaterials activated by ultrasound will provide a new pathway and realize application in disease treatment.

The fundamentals and applications of piezoelectric materials for tumor therapy: recent advances and outlook

Malignant tumors are one of the main diseases leading to death, and the vigorous development of nanotechnology has opened up new frontiers for antitumor therapy. Currently, researchers are focused on solving the biomedical challenges associated with traditional anti-tumor medical methods, promoting the research and development of nano-drug carriers and new nano-drugs, which brings great hope for improving the curative effect and reducing toxic and side effects. Among the new systems being investigated, piezoelectric nano biomaterials, including ferroelectrics, piezoelectric and pyroelectric materials, have recently received extensive attention for antitumor applications. By coupling force, light, magnetism or heat and electricity, polarized charges are generated in these materials microscopically, forming a piezo-potential and establishing a built-in electric field. Polarized charges can directly act on the materials in the tumor micro-environment and also assist in the separation of carriers and inhibit recombination based on piezoelectric theory and piezoelectric optoelectronic theory. Based on this, piezoelectric materials convert various forms of primary energy (such as light energy, mechanical energy, thermal energy and magnetic energy) from the surrounding environment into secondary energy (such as electrical energy and chemical energy). Herein, we review the basic theory and principles of piezoelectric materials, pyroelectric materials and ferroelectric materials as nanomedicine. Then, we summarize the types of piezoelectric materials reported to date and their wide applications in treatment, imaging, device construction and probe detection in various tumor treatment fields. Based on this, we discuss the relevant characteristics and post-processing strategies of nano piezoelectric biomaterials to obtain the maximum piezoelectric response. Finally, we present the key challenges and future prospects for the development of ferroelectric, piezoelectric and pyroelectric nanomaterial-based nanoagents for efficient energy harvesting and conversion for desirable therapeutic outcomes.

Recent Advancements in Ultrasound Transducer: From Material Strategies to Biomedical Applications

Ultrasound is extensively studied for biomedical engineering applications. As the core part of the ultrasonic system, the ultrasound transducer plays a significant role. For the purpose of meeting the requirement of precision medicine, the main challenge for the development of ultrasound transducer is to further enhance its performance. In this article, an overview of recent developments in ultrasound transducer technologies that use a variety of material strategies and device designs based on both the piezoelectric and photoacoustic mechanisms is provided. Practical applications are also presented, including ultrasound imaging, ultrasound therapy, particle/cell manipulation, drug delivery, and nerve stimulation. Finally, perspectives and opportunities are also highlighted.

Bite Force Transducers and Measurement Devices

In dental research, bite force has become an important curative effect evaluation index for tooth restoration, periodontal treatment, and orthodontic treatment. Bite force is an important parameter to evaluate the efficacy of the masticatory system. Physicians obtain the therapeutic basis for occlusal adjustment by measuring the bite force and the dynamic changes in occlusal contact at different stages of treatment and objectively evaluate the therapeutic effect. At present, many devices are used to record the bite force. Most of these devices use force transducers to detect bite force, such as strain gauge transducers, piezoresistive transducers, piezoelectric transducers, optical fiber transducers, and pressure-sensitive films. This article summarizes the various equipment used to record bite force, related materials and the characteristics of this equipment. It provides a reference for physicians to make choices during the clinical process and at the same time provides a basis for the development of new occlusal force measurement materials.