The results revealed that at pH 7.4 CSQ appeared to increase cell permeability in dose-dependent manner, and this effect was relatively reversible at the lower doses of 0.05-1.25 selleck chemical mM. The higher
DQ and ES caused the higher permeability of FD-4. Cytotoxicity of CSQ was concentration, %DQ, and %ES dependent. Substitution with hydrophobic moiety caused decreasing in permeability of FD-4 and cytotoxicity by benzyl group had more effect than octyl group. These studies demonstrated that these novel modified chitosan derivatives had potential for using as absorption enhancers.”
“N,N’-Bis(benzoyl) suberic acid dihydrazide (NA) as nucleating agent for poly(L-lactic acid) (PLLA) was synthesized from benzoyl hydrazine and suberoyl chloride, which was deprived from suberic acid via acylation. PLLA/NA samples were prepared by melt blending and a hot-press forming process. The nonisothermal and isothermal crystallization, spherulite morphology, and melting behavior of PLLA/NA with different contents of NA were investigated with differential scanning calorimetry, depolarized-light intensity measurement, scanning electron microscopy, polarized optical microscopy, and wide-angle X-ray diffraction. With the incorporation of NA, the crystallization peak became sharper and shifted to a higher temperature as the degree of supercooling decreased at a cooling rate of 1
degrees C/min selleck chemicals from the melt. Nonisothermal crystallization indicated that the presence of NA accelerated the overall PLLA crystallization. In isothermal crystallization from the melt, Selleck SB203580 the presence of NA affected the isothermal crystalline behaviors of PLLA remarkably. The addition of NA led to a shorter crystallization time and a faster overall crystallization rate; this meant that there was a heterogeneous nucleation effect of NA on the crystallization of PLLA. With the addition of 0.8% NA, the crystallization half-time of PLLA/NA decreased from 26.5 to 1.4 min at 115 degrees
C. The Avrami theory was used to describe the kinetics of isothermal crystallization of the PLLA/NA samples. Also, with the presence of NA, the spherulite number of PLLA increased, and the spherulite size decreased significantly. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 1408-1416, 2011″
“Topical application of plasmid DNA represents an attractive route of gene delivery. Although chitosan (CS) has been widely investigated as a gene-carrier, there is very limited information about the skin application of CS-based systems for DNA. This study evaluated pDNA-loaded chitosan nanoparticles (CS-NPs) for skin gene delivery. NPs were prepared by inducing the gelation of CS upon interaction with sodium tripolyphosphate. pSV-beta-Gal was used as a reporter gene. The size, surface charge, and the other in vitro characteristics of CS-NPs were examined.