The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different \%para\% substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 33...The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different \%para\% substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 330 nm and an abnormally long wavelength emission ranging from 460 to 550 nm. The long wavelength emission was found strongly dependent of the electron donating capacity of the substituent at the anilino moiety and a stronger electron donating substituent led to a red shift in the emission. The energies of the long wavelength emission of the BAs were correlated to the oxidation potentials of the donors, E \-\{D/D +\}, and a nice linear correlation was found with a slope of +0 66, which clearly pointed to the charge transfer character of the emissive state for the long wavelength emission and the high decoupling extent of the charges in the CT state. This is the first report that shows the direct evidence for the CT nature. The results might be of significance in understanding the photophysics of peptide and protein and in designing novel fluorescent chemosensors.展开更多
Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin w...Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin was prepared by reversal-phase emulsion evaporation.For pharmacodynamic study, insulin (2.5 IU*kg-1) was intravenously administered in phosphated-buffered saline (PBS) solution, conventional liposomes, and PEG-coated liposomes, separately, to normal Wistar rats.Blood glucose levels were determined by the glucose oxidase method.Results The mean diameter of the PEG-coated liposomal insulin was 58.4 nm, while the encapsulation ratio reached 18.33%.After intravenous administration of insulin solution, insulin liposome, and PEG-coated liposomal insulin, the minimum blood glucose concentrations (Cmin %) reached 25.26±5.75%, 33.92±12.42%, and 42.39±10.5% of the initial level, respectively, and the time periods to reach the minimum blood glucose level (Tmin) were 0.7±0.3 h, 1.2±0.4 h, and 2.3±0.7 h, respectively.The relative pharmacological bioavailabilities of insulin liposome and PEG-coated liposomal insulin were 98.03% and 99.70%, respectively, compared with the control of insulin solution.Conclusion PEG-coated liposome can be developed as a relatively sustained injectable delivery system for insulin.Moreover, the liposome coated with PEG may have advantages over normal liposome.展开更多
文摘The fluorescence spectra in cyclohexane of a series of benzanilides(BAs) with different \%para\% substituents at the anilino moiety revealed that BAs emitted dual fluorescence, with one normal weak emission at ca . 330 nm and an abnormally long wavelength emission ranging from 460 to 550 nm. The long wavelength emission was found strongly dependent of the electron donating capacity of the substituent at the anilino moiety and a stronger electron donating substituent led to a red shift in the emission. The energies of the long wavelength emission of the BAs were correlated to the oxidation potentials of the donors, E \-\{D/D +\}, and a nice linear correlation was found with a slope of +0 66, which clearly pointed to the charge transfer character of the emissive state for the long wavelength emission and the high decoupling extent of the charges in the CT state. This is the first report that shows the direct evidence for the CT nature. The results might be of significance in understanding the photophysics of peptide and protein and in designing novel fluorescent chemosensors.
文摘Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin was prepared by reversal-phase emulsion evaporation.For pharmacodynamic study, insulin (2.5 IU*kg-1) was intravenously administered in phosphated-buffered saline (PBS) solution, conventional liposomes, and PEG-coated liposomes, separately, to normal Wistar rats.Blood glucose levels were determined by the glucose oxidase method.Results The mean diameter of the PEG-coated liposomal insulin was 58.4 nm, while the encapsulation ratio reached 18.33%.After intravenous administration of insulin solution, insulin liposome, and PEG-coated liposomal insulin, the minimum blood glucose concentrations (Cmin %) reached 25.26±5.75%, 33.92±12.42%, and 42.39±10.5% of the initial level, respectively, and the time periods to reach the minimum blood glucose level (Tmin) were 0.7±0.3 h, 1.2±0.4 h, and 2.3±0.7 h, respectively.The relative pharmacological bioavailabilities of insulin liposome and PEG-coated liposomal insulin were 98.03% and 99.70%, respectively, compared with the control of insulin solution.Conclusion PEG-coated liposome can be developed as a relatively sustained injectable delivery system for insulin.Moreover, the liposome coated with PEG may have advantages over normal liposome.
