The simultaneous γ-ray-radiation-induced grafting polymerization of acrylic acid on ex- panded polytetrafluoroethylene （ePTFE） film was investigated. It was found that the degree of grafting （DG） of poly（acrylic...The simultaneous γ-ray-radiation-induced grafting polymerization of acrylic acid on ex- panded polytetrafluoroethylene （ePTFE） film was investigated. It was found that the degree of grafting （DG） of poly（acrylic acid） （PAA） can be controlled by the monomer concentration, absorbed dose, and dose rate under an optimal inhibitor concentration of [Fe2＋]=18 mmol/L. SEM observation showed that the macroporous structure in ePTFE films would be covered gradually with the increase of the DG of PAA. The prepared ePTFE-g-PAA film was im- mersed in a neutral silver nitrate solution to fabricate an ePTFE-g-PAA/Ag hybrid film after the addition of NaBH4 as a reduction agent of Ag＋ to Ag atom. SEM, XRD, and XPS results proved that Ag nanoparticles with a size of several tens of nanometers to 100 nanometers were in situ immobilized on ePTFE film. The loading capacity of Ag nanoparticles could be tuned by the DG of PAA, and determined by thermal gravimetric analysis. The quart- titative antibacterial activity of the obtained ePTFE-g-PAA/Ag hybrid films was measured using counting plate method. It can kill all the Escherichia coli in the suspension in 1 h. Moreover, this excellent antibacterial activity can last at least for 4 h. This work provides a facile and practical way to make ePTFE meet the demanding antimicrobial requirement in more and more practical application areas.展开更多
Smart nanoparticles that respond to pathophysiological parameters,such as p H,GSH,and H2O2,have been developed with the huge and urgent demand for the high-efficient drug delivery systems(DDS)for cancer therapy.Herein...Smart nanoparticles that respond to pathophysiological parameters,such as p H,GSH,and H2O2,have been developed with the huge and urgent demand for the high-efficient drug delivery systems(DDS)for cancer therapy.Herein,cubic poly(ethylene glycol)(PEG)-modified mesoporous amorphous iron oxide(AFe)nanoparticles(AFe-PEG)have been successfully prepared as p H-stimulated drug carriers,which can combine doxorubicin(DOX)with a high loading capacity of 948 mg/g,forming a novel multifunctional AFe-PEG/DOX nanoparticulate DDS.In an acidic microenvironment,the AFe-PEG/DOX nanoparticles will not only release DOX efficiently,but also release Fe ions to catalyze the transformation of H2O2 to·OH,acting as fenton reagents.In vitro experimental results proved that the AFe-PEG/DOX nanoparticles can achieve combination of chemotherapeutic(CTT)and chemodynamic therapeutic(CDT)effects on Hela tumor cells.Furthermore,the intrinsic magnetism of AFePEG/DOX makes its cellular internalization efficiency be improved under an external magnetic field.Therefore,this work develops a new and promising magnetically targeted delivery and dual CTT/CDT therapeutic nano-medicine platform based on amorphous iron oxide.展开更多
文摘The simultaneous γ-ray-radiation-induced grafting polymerization of acrylic acid on ex- panded polytetrafluoroethylene （ePTFE） film was investigated. It was found that the degree of grafting （DG） of poly（acrylic acid） （PAA） can be controlled by the monomer concentration, absorbed dose, and dose rate under an optimal inhibitor concentration of [Fe2＋]=18 mmol/L. SEM observation showed that the macroporous structure in ePTFE films would be covered gradually with the increase of the DG of PAA. The prepared ePTFE-g-PAA film was im- mersed in a neutral silver nitrate solution to fabricate an ePTFE-g-PAA/Ag hybrid film after the addition of NaBH4 as a reduction agent of Ag＋ to Ag atom. SEM, XRD, and XPS results proved that Ag nanoparticles with a size of several tens of nanometers to 100 nanometers were in situ immobilized on ePTFE film. The loading capacity of Ag nanoparticles could be tuned by the DG of PAA, and determined by thermal gravimetric analysis. The quart- titative antibacterial activity of the obtained ePTFE-g-PAA/Ag hybrid films was measured using counting plate method. It can kill all the Escherichia coli in the suspension in 1 h. Moreover, this excellent antibacterial activity can last at least for 4 h. This work provides a facile and practical way to make ePTFE meet the demanding antimicrobial requirement in more and more practical application areas.
基金supported by the National Natural Science Foundation of China(No.51473152 and No.51573174)Scientific Research Foundation for Young Talents from Fujian Provincial Department of Education(No.JT180494)Scientific Research Platform Construction Project from Fujian Provincial Department of Science and Technology(No.2018H2002)。
文摘Smart nanoparticles that respond to pathophysiological parameters,such as p H,GSH,and H2O2,have been developed with the huge and urgent demand for the high-efficient drug delivery systems(DDS)for cancer therapy.Herein,cubic poly(ethylene glycol)(PEG)-modified mesoporous amorphous iron oxide(AFe)nanoparticles(AFe-PEG)have been successfully prepared as p H-stimulated drug carriers,which can combine doxorubicin(DOX)with a high loading capacity of 948 mg/g,forming a novel multifunctional AFe-PEG/DOX nanoparticulate DDS.In an acidic microenvironment,the AFe-PEG/DOX nanoparticles will not only release DOX efficiently,but also release Fe ions to catalyze the transformation of H2O2 to·OH,acting as fenton reagents.In vitro experimental results proved that the AFe-PEG/DOX nanoparticles can achieve combination of chemotherapeutic(CTT)and chemodynamic therapeutic(CDT)effects on Hela tumor cells.Furthermore,the intrinsic magnetism of AFePEG/DOX makes its cellular internalization efficiency be improved under an external magnetic field.Therefore,this work develops a new and promising magnetically targeted delivery and dual CTT/CDT therapeutic nano-medicine platform based on amorphous iron oxide.
