Biomacromolecules. 2009 Aug 10; 10(8): 2175-82Gao Y, Zhang Z, Chen L, Gu W, Li YThe selective introduction of a trimethylammonium cationic group into the C-6 position of chitosan (Cs) was successfully performed by "click chemistry" for the first time, and the 6-N,N,N-trimethyltriazole-Cs (TCs) showed good solubility in water. TCs showed strong DNA binding ability and high protection of DNA against nuclease degradation assessed by gel electrophoresis assay. TCNs showed lower degree of flocculation than Cs/DNA self-assembled nanoparticles (CsNs) in the presence of medium containing serum within 60 min. The introduction of trimethyltriazole group led to significantly increased cellular uptake compared with unmodified Cs, which resulted in higher transfection efficiency in HEK 293 and MDA-MB-468 cells. TCs were noncytotoxic, and viability of cells exposure to TCNs for 24 h was over 80% even at 50 microg/mL of polymer. These results suggested that TCs could be an efficient and safe material for gene delivery.

Biol Pharm Bull. 2009 Sep; 32(9): 1533-7Sun X, Zhang X, Hu H, Lu Y, Chen J, Yasuda K, Wang HProliferation of hepatic stellate cells (HSCs) is central for the development of fibrosis during liver injury. Our aim in this study was to determine whether berberine could inhibit HSC proliferation in vitro and prevent experimental liver fibrosis in vivo. Activated rat hepatic stellate cells (CFSCs) were incubated with various concentrations (0-20 microg/ml) of berberine. After 48 h incubation, berberine significantly inhibited CFSC proliferation and induced cell cycle arrest in G1 phase. Real-time and Western blotting revealed that both p21 and p27 expression was markedly reduced by berberine. Berberine also decreased Akt phosphorylation and FoxO1 phosphorylation, which led to FoxO1 nuclear translocation. Berberine effectively prevented CCl(4)-induced liver fibrosis in mice, which was accompanied by a decrease in the number of activated HSCs. Thus, berberine was able to prevent liver fibrosis by inhibition of hepatic stellate cell proliferation.