RESUMO
The massive accumulation of exudate containing high concentrations of glucose causes wound infection and triggers the release of inflammatory factors, which in turn delays the closure of diabetic wounds. In this study, a Janus membrane is constructed by combining glucose oxidase (GOx) and copper ions (Cu2+) for the treatment of diabetic wounds, which is named as Janus@GOx/Cu2+. It consists of hydrophobic, transitional, and superhydrophilic layers in a three-layer structure with gradient hydrophilicity for self-pumping properties. The Janus@GOx/Cu2+ membrane triggers a series of cascading reactions while pumping out diabetic wound exudates. First, glucose oxidase loaded onto the hydrophilic layer of the Janus@GOx/Cu2+ membrane decomposes glucose into hydrogen peroxide (H2O2) and glucuronic acid, reducing the local glucose level. The generated glucuronic acid neutralizes the local alkaline environment of chronic wounds. Simultaneously, the H2O2 interacts with the Cu2+ contained in the hydrophobic layers of the Janus@GOx/Cu2+ membrane via a Fenton-like reaction, generating hydroxyl radicals with excellent bactericidal properties. Cu2+ promotes angiogenesis and wound healing in diabetic wounds. Under the action of multiple responses, the Janus@GOx/Cu2+ membrane promotes wound healing in diabetic infections.
RESUMO
Piezoelectric ceramics are piezoelectric materials with polycrystalline structure and have been widely used in many fields such as medical imaging and sound sensors. As knowledge about this kind of material develops, researchers find piezoelectric ceramics possess favorable piezoelectricity, biocompatibility, mechanical properties, porous structure and antibacterial effect and endeavor to apply piezoelectric ceramics to the field of bone tissue engineering. However, clinically no piezoelectric ceramics have been exercised so far. Therefore, in this paper we present a comprehensive review of the research and development of various piezoelectric ceramics including barium titanate, potassium sodium niobate and zinc oxide ceramics and aims to explore the application of piezoelectric ceramics in bone regeneration by providing a detailed overview of the current knowledge and research of piezoelectric ceramics in bone tissue regeneration.