Objective To explore the effects of hydroxytyrosol-mediated macrophage polarization on burn wound healing in rats.Methods SD rats were randomly divided into burn group,hydroxytyrosol group,hydroxytyrosol+ov-NC group and hydroxytyrosol+ov-S100A9 group,with 10 rats in each group.Burn model was established by metal weight burn method.Wound healing rate was calculated;HE staining was used to observe the pathological changes of wound skin tissue in rats;immunofluorescence was used to detect the ratios of M1 and M2 macrophages in the wound skin of rats;ELISA was used to detect the levels of macrophage inflammatory factors in the wound skin of rats;Western blot was used to detect the expression of S100A9/TLR4/NF-κB signal pathway in wound skin of rats.Results Compared with the burn group,hydroxytyrosol group and hydroxytyrosol+ov-NC group demonstrated higher wound healing ability and alleviated pathological damage,lower levels of M1 type macrophages and related factors,higher levels of M2 type macrophages and related factors,and lower expression of S100A9,TLR4 and p-NF-κB p65 proteins.Compared with hydroxytyrosol group and hydroxytyrosol+ov-NC group,S100A9 overexpression reduced the wound healing ability and aggravated the pathological damage,increased M1 type macrophages and related factors,decreased M2 type macrophages and related factors,and increased the expression of S100A9,TLR4 and p-NF-κB p65 proteins in hydroxytyrosol+ov-S100A9 group.Conclusion Hydroxytyrosol promotes wound healing in burn rats by down-regulating S100A9,and its mechanism may be related to inhibiting the activation of TLR4/NF-κB signaling pathway and improving the imbalance of M1/M2 macrophages.

Objective To explore the effects of hydroxytyrosol-mediated macrophage polarization on burn wound healing in rats.Methods SD rats were randomly divided into burn group,hydroxytyrosol group,hydroxytyrosol+ov-NC group and hydroxytyrosol+ov-S100A9 group,with 10 rats in each group.Burn model was established by metal weight burn method.Wound healing rate was calculated;HE staining was used to observe the pathological changes of wound skin tissue in rats;immunofluorescence was used to detect the ratios of M1 and M2 macrophages in the wound skin of rats;ELISA was used to detect the levels of macrophage inflammatory factors in the wound skin of rats;Western blot was used to detect the expression of S100A9/TLR4/NF-κB signal pathway in wound skin of rats.Results Compared with the burn group,hydroxytyrosol group and hydroxytyrosol+ov-NC group demonstrated higher wound healing ability and alleviated pathological damage,lower levels of M1 type macrophages and related factors,higher levels of M2 type macrophages and related factors,and lower expression of S100A9,TLR4 and p-NF-κB p65 proteins.Compared with hydroxytyrosol group and hydroxytyrosol+ov-NC group,S100A9 overexpression reduced the wound healing ability and aggravated the pathological damage,increased M1 type macrophages and related factors,decreased M2 type macrophages and related factors,and increased the expression of S100A9,TLR4 and p-NF-κB p65 proteins in hydroxytyrosol+ov-S100A9 group.Conclusion Hydroxytyrosol promotes wound healing in burn rats by down-regulating S100A9,and its mechanism may be related to inhibiting the activation of TLR4/NF-κB signaling pathway and improving the imbalance of M1/M2 macrophages.

The thermooxidative degradtion of ethylene oxide and tetra-hydrofuran (EO-THF) co-polyether has been studied by electron spin resonance(ESR),Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. The initial degradation site was found to be at the α-carbon of the ether bond. Two free radicals which derived from dehydrogenation and oxygen addition were successfully detected by spin-trapping technique which used α-phenyl-N-tert-butyl nitrone (PBN) as spin trap. Both FT-IR and NMR have been used tofollow structural changes of the copolyether during degradation. Nearly 20 product frngnents including formate,carbonate,methyl,alcohol,methylene-dioxy,hydroperoxide and semiformal have been characterized by 1 D and 2 D NMR.The thermooxidtion of co-polyether preferred to occur on the THF units especially at the alternating linkage of EO and THF.Antioxidant (BHT) not only retarded the thermooxidation but also modified the degradation products with less ester and methylene-dioxy groups but more hydroxyl and methyl groups.