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Uncontrolled and persistent inflammation is closely related to numerous acute and chronic diseases. However, effective targeting delivery systems remain to be developed for precision therapy of inflammatory diseases. Herein we report a novel strategy for engineering inflammation-accumulation nanoparticles via phenolic functionalization. Different phenol-functionalized nanoparticles were first developed, which can undergo in situ aggregation upon triggering by the inflammatory/oxidative microenvironment. Phenolic compound-decorated poly (lactide-co-glycolide) nanoparticles, in particular tyramine (Tyr)-coated nanoparticles, showed significantly enhanced accumulation at inflammatory sites in mouse models of colitis, acute liver injury, and acute lung injury, mainly resulting from in situ cross-linking and tissue anchoring of nanoparticles triggered by local myeloperoxidase and reactive oxygen species. By combining a cyclodextrin-derived bioactive material with Tyr decoration, a multifunctional nanotherapy (TTN) was further developed, which displayed enhanced cellular uptake, anti-inflammatory activities, and inflammatory tissue accumulation, thereby affording amplified therapeutic effects in mice with colitis or acute liver injury. Moreover, TTN can serve as a bioactive and inflammation-targeting nanoplatform for site-specifically delivering a therapeutic peptide to the inflamed colon post oral administration, leading to considerably potentiated in vivo efficacies. Preliminary studies also revealed good safety of orally delivered TTN. Consequently, Tyr-based functionalization is promising for inflammation targeting amplification and therapeutic potentiation of nanotherapies.
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BACKGROUND:Bone marrow is the main source of mesenchymal stem cells(MSCs)at present,but its application has been limited,because of some reasons such as inconvenience of isolation,and the quantity of cells decreases with human increased age.Umbilical cord as a new source of MSCs has been widespread concerned recently.OBJECTIVE:To explore the approach of isolating and culturing MSCs from Wharton's jelly of human umbilical cord,and the methods of identifying the surface antigens and the differentiation potential.METHODS:MSCs were isolated and amplified via tissue-cultivation,and cultured by FasGrow medium.Morphology of MSCs from Wharton's jelly of human umbilical cord was observed under the optical microscope.Its immunophenotypes were detected using immunohistochemistry.The differentiation of MSCs into the osteoblasts was determined utilizing Gomori calcium-cobalt alkaline phosphatase staining,von Kossa calcium node staining,and tetracyclinefluorescence labeling.The differentiation of MSCs into the adipocytes was detected using oil red O staining.RESULTS AND CONCLUSION:MSCs were easily obtained from Wharton's jelly of human umbilical cord via the proposed approach.The primary cells grew up to 70%-80% confluence after 12-16 days of culture,and meanwhile the undifferentiated state was maintained and proliferation was stabilized after passage.The cell cycle of double increase was about 2 days,and proliferation in vitro reached twenty generation above.Surface antigen analysis showed that CD44,CD105,CD133,MHC-I were positively expressed,while CD34,CD45 were negatively expressed.Experiments of differentiation in vitro indicated that the obtained cells were capable of differentiating into fat,osteoblast and nerve-like cells.
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@#ObjectiveTo investigate the feasibility and optimal condition of isolation,purification and expansion of mesenchymal stem cells(MSCs) derived from human umbilical cord blood in vtro.MethodsHuman umbilical cord blood(HUCB) was collected from full term deliveries scheduled,all samples were obtained sterilely with 20 U/ml preservative free heparin.The cord mononuclear cells were isolated with lymphocyte separation medium(density 1.077 g/ml),purified and expanded with MesencultTM medium and acidic environment to produce adherent layer.The surface antigen expression of MSCs was detected with flow cytometry.ResultsThe HUCB-derived mononuclear cells,when seeded in specific medium,gave rise to adherent cells,which exhibited either an osteoclast or mesenchymal-like phenotype.After passage 3,these cells were able to be purified and expanded.6.6×105 primary MSCs reached a number of 9.9×10<>sup8 after 10 expanded passage.Flow cytometry showed that MSCs did not express antigens CD34,CD11a and CD11b,but express strongly CD29 and weakly CD71,which was identical to human bone marrow-derived MSCs.ConclusionMSCs in HUCB can be cultured and expanded in vitro,and could be a source of stem cells for experimental and clinical application.