Proangiogenic effect and underlying mechanism of holmium oxide nanoparticles: a new biomaterial for tissue engineering.

BACKGROUND: Early angiogenesis provides nutrient supply for bone tissue repair, and insufficient angiogenesis will lead tissue engineering failure. Lanthanide metal nanoparticles (LM NPs) are the preferred materials for tissue engineering and can effectively promote angiogenesis. Holmium oxide nanoparticles (HNPs) are LM NPs with the function of bone tissue "tracking" labelling. Preliminary studies have shown that HNPs has potential of promote angiogenesis, but the specific role and mechanism remain unclear. This limits the biological application of HNPs. RESULTS: In this study, we confirmed that HNPs promoted early vessel formation, especially that of H-type vessels in vivo, thereby accelerating bone tissue repair. Moreover, HNPs promoted angiogenesis by increasing cell migration, which was mediated by filopodia extension in vitro. At the molecular level, HNPs interact with the membrane protein EphrinB2 in human umbilical vein endothelial cells (HUVECs), and phosphorylated EphrinB2 can bind and activate VAV2, which is an activator of the filopodia regulatory protein CDC42. When these three molecules were inhibited separately, angiogenesis was reduced. CONCLUSION: Overall, our study confirmed that HNPs increased cell migration to promote angiogenesis for the first time, which is beneficial for bone repair. The EphrinB2/VAV2/CDC42 signalling pathway regulates cell migration, which is an important target of angiogenesis. Thus, HNPs are a new candidate biomaterial for tissue engineering, providing new insights into their biological application.

Teadenol B as a Component of Microorganism-Fermented Tea Extract Inhibited Breast Cancers by Promoting Autophagy.

Breast cancer is a significant threat to life and health, which needs more safe and effective drugs to be explored. Teadenol B is a characteristic chemical component of microbial fermented tea. This study discovered that teadenol B could exhibit obvious inhibitory effects on all four different clinical subtype characteristics of breast cancer cells. Proteomic studies show that deoxycytidine triphosphate deaminase (DCTD), which could block DNA synthesis and repair DNA damage, had the most significant and consistent reduction in all four types of breast cancer cells with the treatment of teadenol B. Considering MDA-MB-231 cells exhibit poor clinical prognosis and displayed substantial statistical differences in KEGG pathway enrichment analysis results, we investigated its impact on the size and growth of MDA-MB-231 triple-negative breast tumors transplanted into nude mice and demonstrated that teadenol B significantly suppressed tumor growth without affecting body weight significantly. Finally, we found that the conversion of LC3-I to LC3-II in MDA-MB-231 increased significantly with teadenol B treatment. This proved that teadenol B could be a strong autophagy promotor, which explained the down-regulation of DCTD to some extent and may be the potential mechanism underlying teadenol B's anti-breast cancer effects. This finding provides new evidence for drinking fermented tea to prevent breast cancer and highlights the potential of teadenol B as a novel therapeutic option for breast cancer prevention and treatment, necessitating further investigations to clarify its exact target and the details involved.

Rapid and sensitive detection of SARS-CoV-2 based on a phage-displayed scFv antibody fusion with alkaline phosphatase and NanoLuc luciferase.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the subsequent pandemic have led to devastating public health and economic losses. The development of highly sensitive, rapid and inexpensive methods to detect and monitor coronaviruses is essential for family diagnosis, preventing infections, choosing treatments and programs and laying the technical groundwork for viral diagnosis. This study established one-step immunoassays for rapid and sensitive detection of SARS-CoV-2 by using a single-chain variable fragment (scFv) fused to alkaline phosphatase (AP) or NanoLuc (NLuc) luciferase. First, a high-affinity scFv antibody specific to the SARS-CoV-2 nucleocapsid (N) protein was screened from hybridoma cells-derived and phage-displayed library. Next, prokaryotic expression of the scFv-AP and scFv-NLuc fusion proteins were induced, leading to excellent antibody binding properties and enzyme catalytic activities. The scFv-AP fusion had a detection limit of 3 pmol per assay and was used to produce eye-readable biosensor readouts. Moreover, the scFv-NLuc protein was applied in a highly sensitive luminescence immunoassay, achieving a detection limit lower than 0.1 pmol per assay. Therefore, the scFv-AP and scFv-NLuc fusion proteins can be applied for the rapid and simple diagnosis of SARS-CoV-2 to safeguard human health and provide guidance for the detection of other pathogenic viruses.