In order to investigate a key factor for the appearance of proton conductivity in chitin-chitosan mixed compounds, the chitin-chitosan mixed compounds (chitin)x(chitosan)1-x were prepared and these proton conductiviti...In order to investigate a key factor for the appearance of proton conductivity in chitin-chitosan mixed compounds, the chitin-chitosan mixed compounds (chitin)x(chitosan)1-x were prepared and these proton conductivities have been investigated. DC proton conductivity σ is obtained from Nyquist plot of impedance measurement data, and the relationship between σ and mixing ratio x has been made clear. It was found that the x dependence of σ is non-monotonous. That is, σ shows the anomalous behavior, and has peaks around x = 0.4 and 0.75. This result indicates that there exist optimal conditions for the realization of high-proton conductivity in the chitin-chitosan mixed compound in which the number of acetyl groups is different. From the FT-IR measurement, we have found that the behavior of proton conductivity in (chitin)x(chitosan)1-x is determined by the amount of water content changed by x. Using these results, proton conductivity, which is important for the application of conducting polymers in chitin-chitosan mixed compounds, will be able to be easily controlled by adjusting the mixing ratio x.展开更多
Chitosan-based nanocarriers(CS-NCs)show a promising role in improving drugs and bioactive compounds delivery for therapy.However,the effects exerted by CS-NCs at the cellular level,including their recognition and upta...Chitosan-based nanocarriers(CS-NCs)show a promising role in improving drugs and bioactive compounds delivery for therapy.However,the effects exerted by CS-NCs at the cellular level,including their recognition and uptake,have not been fully investigated yet.Many factors,including size,shape,concentration,and surface chemistry of CS-NCs,play an important role in determining the types of intracellular signals triggered.The mechanism of uptake and the involvement of the cytoskeleton during the CS-NCs endocytosis variates among the different cell types as well as further effects observed inside cells.In the present work,we discuss the effects induced by CS-NCs per se on the cytoskeleton,a key component in cell architecture and physiology.The focus of this report is made on tumoral and normal biological models in which CS-NCs could differentially affect the cell cytoskeleton.The recent years reports regarding the impact of CS-NCs on cytoskeleton dynamics and the current techniques for its evaluation are summarized and discussed.Understanding mechanisms underlying cytoskeletal impact after cell exposure to CS-NCs is critical for the design of safest value-added formulations in the biomedical field.Furthermore,this revision points out some interesting aspects of cytoskeletal changes and cell death encompassing anti-tumoral effects.展开更多
文摘In order to investigate a key factor for the appearance of proton conductivity in chitin-chitosan mixed compounds, the chitin-chitosan mixed compounds (chitin)x(chitosan)1-x were prepared and these proton conductivities have been investigated. DC proton conductivity σ is obtained from Nyquist plot of impedance measurement data, and the relationship between σ and mixing ratio x has been made clear. It was found that the x dependence of σ is non-monotonous. That is, σ shows the anomalous behavior, and has peaks around x = 0.4 and 0.75. This result indicates that there exist optimal conditions for the realization of high-proton conductivity in the chitin-chitosan mixed compound in which the number of acetyl groups is different. From the FT-IR measurement, we have found that the behavior of proton conductivity in (chitin)x(chitosan)1-x is determined by the amount of water content changed by x. Using these results, proton conductivity, which is important for the application of conducting polymers in chitin-chitosan mixed compounds, will be able to be easily controlled by adjusting the mixing ratio x.
基金ANPCyT(PICTs 2015-3866 and 2017-1683)Universidad de Buenos Aires UBACyT 20020190100297BA and CONICET.
文摘Chitosan-based nanocarriers(CS-NCs)show a promising role in improving drugs and bioactive compounds delivery for therapy.However,the effects exerted by CS-NCs at the cellular level,including their recognition and uptake,have not been fully investigated yet.Many factors,including size,shape,concentration,and surface chemistry of CS-NCs,play an important role in determining the types of intracellular signals triggered.The mechanism of uptake and the involvement of the cytoskeleton during the CS-NCs endocytosis variates among the different cell types as well as further effects observed inside cells.In the present work,we discuss the effects induced by CS-NCs per se on the cytoskeleton,a key component in cell architecture and physiology.The focus of this report is made on tumoral and normal biological models in which CS-NCs could differentially affect the cell cytoskeleton.The recent years reports regarding the impact of CS-NCs on cytoskeleton dynamics and the current techniques for its evaluation are summarized and discussed.Understanding mechanisms underlying cytoskeletal impact after cell exposure to CS-NCs is critical for the design of safest value-added formulations in the biomedical field.Furthermore,this revision points out some interesting aspects of cytoskeletal changes and cell death encompassing anti-tumoral effects.
