Résumé
Aim To prepare hyaluronic acid nanoparti-cles(Ade/GA-HA) using glycyrrhetinic acid modified hyaluronic acid as the carrier and adenine as a model drug, and analyze their physicochemical property and proliferation effect on Bel-7402 cells. Methods Gly-cyrrhetinic acid and hyaluronic acid were combined by chemical cross-linking method, dialysis and freeze-dr-ying,based on which Ade/GA-HA was prepared using ultrasonic method, and the particle size and Zeta po-tential were determined by Malvern laser particle analy-zer,and the morphology was observed by transmission electron microscopy, and the absorbance was deter-mined by ultraviolet-visible spectrophotometer, high performance liquid chromatograph and microplate read-er to caculate drug load, encapsulation efficiency and in vitro release. MTT assays were utilized to determine the proliferation of nanoparticles treated Bel-7402 cells. Results GA-HA nanoparticles had spherical shape with a good dispersion, at diameters of 398.1 nm, of which Zeta potential was - 34.2 mV, and presented good short term stability. The drug load and encapsulation efficiency of Ade/GA-HA nanoparticles were (22.5 ± 5.8)% and (87.27 ± 0.33) %, re-spectively. Burst release was observed in Ade/GA-HA nanoparticles within 4 h, while controlled release 4 h later. Compared with free adenine,Ade/GA-HA nano-particles had a stronger inhibitory effect on cell prolif-eration with statistically significant difference. Conclu-sion GA-HA nanoparticles has excellent physico-chemical properties and meet the design requirement.
Résumé
Objective To synthesize miRNA carrier PEG-b-PLL and to testify the stability , encapsulation efficiency and cyto-toxicity of its complexes .Methods H1 NMR was used to determine the degree of polymerization of PLL , 4%agarose gel electrophore-sis was used to determine entrapment of the polyer to the miRNA;then dynamic light scattering ( DLS) was used to measure the hydro-dynamic parameter such as size , polydispersity index ( PDI) and zeta potential of the polyplexes .The entrapment efficiency was deter-mined by ultraviolet-visible spectrophotometer , and finally , the cyto-toxicity of PEG-b-PLL was evaluated by CKK-8 kit with K562 cell lines.Results The characteristics indicated polyplexes prepared by PEG-b-PLL and miRNA fulfill the demand of being the gene carri-er of miRNA because of low cyto-toxicity , high encapsulation efficiency and stability .Conclusion The miRNA carrier PEG-b-PLL had good character and low cyto-toxicity.It showed considerable potential as an efficient miRNA carrier .
Résumé
Kombucha (KT), a fermented black tea (BT), is known to have many beneficial properties. In the present study, antioxidant property of KT has been investigated against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity using murine hepatocytes. TBHP, a reactive oxygen species inducer, causes oxidative stress resulting in organ pathophysiology. Exposure to TBHP caused a reduction in cell viability, increased membrane leakage and disturbed the intra-cellular antioxidant machineries in hepatocytes. TBHP exposure disrupted mitochondrial membrane potential and induced apoptosis as evidenced by flow cytometric analyses. KT treatment, however, counteracted the changes in mitochondrial membrane potential and prevented apoptotic cell death of the hepatocytes. BT treatment also reverted TBHP induced hepatotoxicity, however KT was found to be more efficient. This may be due to the formation of antioxidant molecules like D-saccharic acid-1,4-lactone (DSL) during fermentation process and are absent in BT. Moreover, the radical scavenging activities of KT were found to be higher than BT. Results of the study showed that KT has the potential to ameliorate TBHP induced oxidative insult and cell death in murine hepatocytes more effectively than BT.