Search

Fucoidan, a sulfated polysaccharide with a complex structure, has gradually become the focus of biomedical research due to its remarkable biological activity and low toxicity. In this research, it was noted that low molecular weight fucoidan (LMWF) exhibited significant antimicrobial effects on Methicillin-resistant Staphylococcus aureus (MRSA) and promoted polarization towards M2 macrophages, leading to a substantial reduction in inflammatory responses within the lipopolysaccharide (LPS)-activated macrophages. We further explored the mechanism underlying the anti-inflammation activity. Our findings indicated that LMWF significantly enhanced the phosphorylation level of AMP-activated protein kinase (AMPK), inhibited the phosphorylation of the mammalian target of rapamycin (mTOR), and enhanced the expression of LC3II. Meanwhile, Compound C (CC) substantially reversed the anti-inflammation effect of LMWF, indicating that the AMPK pathway plays a pivotal role in this effect. In in vivo research, LMWF revealed impressive anti-inflammatory potential. LMWF treatment significantly eliminated MRSA and ameliorated inflammatory symptoms in mice's MRSA-infected skin wound model. Further analysis using Western Blot (WB) indicated significant AMPK/mTOR signaling pathway activation in mice treated with LMWF, which led to accelerated polarization of macrophages from the M1 to the M2 phenotype. In summary, we systematically explored the mechanism by which LMWF exerts anti-inflammatory effects through in vitro and in vivo experiments. It was confirmed that LMWF effectively induced the conversion of macrophages to an anti-inflammatory M2 phenotype by activating the AMPK/mTOR pathway. Simultaneously, LMWF effectively eradicated MRSA and accelerated wound healing in mice. This finding provides an important theoretical basis for further research on fucoidan., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Combination therapy based on sonodynamic therapy (SDT) combined with immune checkpoint blockers anti-PD-L1 provides effective anti-tumor effects. We designed a combination therapy based on M1/PLGA@IR780/CAT NPs of SDT-enhanced immunity combined with immune checkpoint blockers against PD-L1, which was based on M1 macrophage membrane-encapsulated poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with the acoustic sensitizer IR780 and catalase (CAT) to successfully realize it. SDT based on M1/PLGA@IR780/CAT NPs could induce tumor cell death by promoting dendritic cell (DC) maturation and modulating the tumor immune microenvironment. In particular, the systemic anti-tumor immune response and potent immune memory induced upon combination with anti-PD-L1 checkpoint blockade not only alleviated the progression of mammary cancer in 4T1 mice and effectively blocked distant metastasis, but also prevented tumor recurrence, providing a promising new therapeutic strategy for clinical tumor therapy., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Niu chengcheng reports financial support was provided by Niu, Chengcheng., (Copyright © 2024 Elsevier Ltd. All rights reserved.)