Musculoskeletal injuries and bone defects represent a significant clinical challenge,necessitating innovative approaches for effective bone tissue regeneration.In this study,we investigated the potential of harnessing...Musculoskeletal injuries and bone defects represent a significant clinical challenge,necessitating innovative approaches for effective bone tissue regeneration.In this study,we investigated the potential of harnessing periosteal stem cells(PSCs)and glycosaminoglycan(GAG)-mimicking materials for in situ bone regeneration.Our findings demonstrated that the introduction of 2-N,6-O sulfated chitosan(26SCS),a GAG-like polysaccharide,enriched PSCs and promoted robust osteogenesis at the defect area.Mechanistically,26SCS amplifies the biological effect of endogenous platelet-derived growth factor-BB(PDGF-BB)through enhancing the interaction between PDGF-BB and its receptor PDGFRβabundantly expressed on PSCs,resulting in strengthened PSC proliferation and osteogenic differentiation.As a result,26SCS effectively improved bone defect repair,even in an osteoporotic mouse model with lowered PDGF-BB level and diminished regenerative potential.Our findings suggested the significant potential of GAG-like biomaterials in regulating PSC behavior,which holds great promise for addressing osteoporotic bone defect repair in future applications.展开更多
Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The...Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 （MMP-7） and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium （DSS）. The UC model was evaluated both by disease activity index （DAI） and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 （IL-6） serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC （colorectal cancer）. The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.展开更多
A novel chemiluminescence （CL） reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex （Ks[Cu（HIO6）2], DPC） in alkaline medium. The CL intensity could be enhanced in the...A novel chemiluminescence （CL） reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex （Ks[Cu（HIO6）2], DPC） in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate （AKS）. A new CL method was developed for the determination of AKS by coupling with flow injection （FI） technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10-7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0 x 10-9-4.0 x 10-6 g/mL with the detection limit of 1.2 x 10-9 g/mL. The relative standard deviation was 2.1% for 8.0xl0-9g/mL AKS （n=9）. The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.展开更多
基金supported by National Natural Science Foundation of China for Innovative Research Groups(No.51621002)the National Natural Science Foundation of China(No.31870953)supported by the 111 Project(B14018).
文摘Musculoskeletal injuries and bone defects represent a significant clinical challenge,necessitating innovative approaches for effective bone tissue regeneration.In this study,we investigated the potential of harnessing periosteal stem cells(PSCs)and glycosaminoglycan(GAG)-mimicking materials for in situ bone regeneration.Our findings demonstrated that the introduction of 2-N,6-O sulfated chitosan(26SCS),a GAG-like polysaccharide,enriched PSCs and promoted robust osteogenesis at the defect area.Mechanistically,26SCS amplifies the biological effect of endogenous platelet-derived growth factor-BB(PDGF-BB)through enhancing the interaction between PDGF-BB and its receptor PDGFRβabundantly expressed on PSCs,resulting in strengthened PSC proliferation and osteogenic differentiation.As a result,26SCS effectively improved bone defect repair,even in an osteoporotic mouse model with lowered PDGF-BB level and diminished regenerative potential.Our findings suggested the significant potential of GAG-like biomaterials in regulating PSC behavior,which holds great promise for addressing osteoporotic bone defect repair in future applications.
基金the grants from the National Natural Science Foundation of China(30800812)
文摘Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 （MMP-7） and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium （DSS）. The UC model was evaluated both by disease activity index （DAI） and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 （IL-6） serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC （colorectal cancer）. The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.
基金supported by the National Natural Science Foundation of China(No.21105133 and No.21127008)the Key Program of Guangdong Provincial Natural Science Foundation(No.9251027501000004)
文摘A novel chemiluminescence （CL） reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex （Ks[Cu（HIO6）2], DPC） in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate （AKS）. A new CL method was developed for the determination of AKS by coupling with flow injection （FI） technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10-7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0 x 10-9-4.0 x 10-6 g/mL with the detection limit of 1.2 x 10-9 g/mL. The relative standard deviation was 2.1% for 8.0xl0-9g/mL AKS （n=9）. The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.
