▎ 摘　　要

Rationale: Graphene oxide (GO) based nanomaterials have shown potential for the diagnosis and treatment of amyloid-beta (A beta)-related diseases, mainly on Alzheimer's disease (AD). However, these nanomaterials have limitations. How GO is beneficial to eliminate A beta burden, and its physiological function in AP-related diseases, still needs to be investigated. Moreover, postoperative cognitive dysfunction (POCD) is an A beta-related common central nervous system complication, however, nanomedicine treatment is lacking. Methods: To evaluate the effects of GO on A beta levels, HEK293T-APP-GFP and SHSY5Y-APP-GFP cells are established. Intramedullary fixation surgery for tibial fractures under inhalation anesthesia is used to induce dysfunction of fear memory in mice. The fear memory of mice is assessed by fear conditioning test. Results: GO treatment maximally alleviated A beta levels by simultaneously reducing A beta generation and enhancing its degradation through inhibiting beta-cleavage of amyloid precursor protein (APP) and improving endosomal A beta delivery to lysosomes, respectively. In postoperative mice, the hippocampal A beta levels were significantly increased and hippocampal-dependent fear memory was impaired. However, GO administration significantly reduced hippocampal A beta levels and improved the cognitive function of the postoperative mice. Conclusion: GO improves fear memory of postoperative mice by maximally alleviating A beta accumulation, providing new evidence for the application of GO-based nanomedicines in A beta-related diseases.