ABSTRACT
The unique ability of piezoelectric materials to generate electricity spontaneously has attracted widespread interest in the medical field. In addition to the ability to convert mechanical stress into electrical energy, piezoelectric materials offer the advantages of high sensitivity, stability, accuracy and low power consumption. Because of these characteristics, they are widely applied in devices such as sensors, controllers and actuators. However, piezoelectric materials also show great potential for the medical manufacturing of artificial organs and for tissue regeneration and repair applications. For example, the use of piezoelectric materials in cochlear implants, cardiac pacemakers and other equipment may help to restore body function. Moreover, recent studies have shown that electrical signals play key roles in promoting tissue regeneration. In this context, the application of electrical signals generated by piezoelectric materials in processes such as bone healing, nerve regeneration and skin repair has become a prospective strategy. By mimicking the natural bioelectrical environment, piezoelectric materials can stimulate cell proliferation, differentiation and connection, thereby accelerating the process of self-repair in the body. However, many challenges remain to be overcome before these concepts can be applied in clinical practice, including material selection, biocompatibility and equipment design. On the basis of the principle of electrical signal regulation, this article reviews the definition, mechanism of action, classification, preparation and current biomedical applications of piezoelectric materials and discusses opportunities and challenges for their future clinical translation.
ABSTRACT
The development of biopolymer-based films for food packaging is increasing owing to their environmental appeal, renewability, and biodegradability. In this study, transparent and biodegradable konjac glucomannan (KGM)/chitosan (CS)/TEMPO-oxidized chitin nanocrystal (TEMPO-ChNCs) bionanocomposite films were prepared. The TEMPO-ChNCs were prepared from chitin using the 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO) oxidation method and were used as a reinforcement nanofiller for the bionanocomposite films. The effect of TEMPO-ChNCs content on both rheological properties of film-forming solutions (FFS) and structural and physical properties of the resultant films was investigated. The rheological results of the FFS revealed that the TEMPO-ChNCs interacted with KGM and CS through electrostatic interaction and the hydrogen bonds in the bionanocomposite matrix, which was in agreement with the Fourier transform infrared spectroscopy and X-ray diffraction results. The microstructure of the films showed that 3% (w/w) TEMPO-ChNCs were homogeneously dispersed within the KGM/CS matrix, reducing the free volume of the biocomposite matrix and improving the final film mechanical and barrier properties (Pâ¯<â¯0.05). Furthermore, these bionanocomposite films exhibited good thermal stability. The incorporation of TEMPO-ChNCs in the KGM/CS matrix produced flexible and transparent bionanocomposite films. Thus, this bionanocomposite films has potential use in food packaging applications.
