BACKGROUND:Chitosan is wel known as good biocompatibility and biodegradability;however, its extensive use in biomedical applications is restricted due to its poor transfection efficiency. OBJECTIVE:To prepare the polyethyleneimine-chitosan/DNA nanoparticles loading enhanced green fluorescent protein gene, and to detect their physicochemical properties and gene transfection efficiency towards chondrocytes in vitro.
METHODS:Low molecular weight polyethyleneimine was covalently linked to chitosan backbone to construct chitosan-graft-polyethyleneimine;then the chitosan-graft-polyethyleneimine was mixed with DNA nanoparticles, which loaded enhanced green fluorescent protein gene, by a complex coacervation method. The nanoparticle morphology was observed under a scanning electron microscopy. The sizes and zeta-potentials of the
nanoparticles were measured by a Marven-nano laser diffractometer. The binding capacity of plasmid DNA was evaluated by agarose gel electrophoresis analysis. The gene transfection experiments in vitro were performed towards rabbit’s chondrocytes. The gene transfection efficiency was measured with flow cytometry and under fluorescence microscope. How marked DNA entered into the nucleus of chondrocytes mediated by the nanoparticles was detected by laser scanning confocal microscopy.
RESULTS AND CONCLUSION:The prepared nanoparticles were mainly spherical, with an average size of (154.6±18.6) nm, and zeta-potential of (24.68±6.82) mV. The agarose gel electrophoresis analysis confirmed that the nanoparticles could effectively protect plasmid DNA from DNase Ⅰ-induced degradation. Gene transfection in vitro proved that the nanoparticles were efficient in transfecting rabbit’s chondrocytes and the expression of green fluorescent proteins was observed under fluorescent microscope, with a transfection efficiency of (23.80±1.74)%that was significantly higher than that of the naked plasmid DNA and chitosan/DNA nanoparticles (P<0.05). But no significant differences were observed between polyethyleneimine-chitosan/DNA nanoparticles and LipofectamineTM 2000. These findings indicate that the polyethyleneimine-chitosan/DNA nanoparticles can effectively protect plasmid DNA from nuclease degradation, and exhibit the favorable transfection ability towards articular chondrocytes.

Objective To observe any effect of transcutaneous electrical nerve stimulation (TENS) on pul monary function,airflow obstruction,dyspnea,exercise capacity and levels of tumor necrosis factor-α (TNF-α) in the sputum of patients with chronic obstructive pulmonary disease (COPD).Methods Thirty patients with stage Ⅰ or Ⅱ COPD were randomly divided into a treatment group and a control group with 15 cases in each.TENS applied at the Feishu acupuncture point (BL13) was used in the treatment group,while sham stimulation of the same point without current output was used in the control group.The treatment was administered 40 minutes once daily,5 days a week for a total of 4 weeks.The outcome measures were measured before and after 4 weeks of treatment.Results FVC,FEV1,FEV1％,and peak expiratory flow rate (PEFR) all improved significantly in the treatment group after 4 weeks of treatment.After treatment,the average TNF-α level in induced sputum and exercise capacity as indicated by the average BODE index had both improved significantly in the treatment group.Compared with the control group,pulmonary function,TNF-α and the BODE index in the treatment group were all significantly better.There was no significant difference in pulmonary function,BODE index or TNF-α before and after treatment in the control group.Conclusion TENS at the Feishu acupoint can reduce airway inflammation,improve pulmonary function and exercise capacity,and decrease TNF-α levels in patients with stage Ⅰ or Ⅱ COPD.This treatment should be very useful for enhancing their ability in the activities of daily living.

Objective To investigate hepatic expressions and significances of cannabinoid receptor 1 (CB1) and cannabinoid receptor 2(CB2) in C57 mice with experimental cirrhosis.Methods Thirty C57 mice were randomly divided into three groups,i.e.normal control group,model control group and model colchicine group.Hepatic fibrosis model was prepared by intraperitoneal injection of carbon tetrachloride.The expressions of CB1 and CB2 in liver tissue of mice were observed by immunohistochemistry.The scores of inflammation grade (G) and fibrosis stage (S) were simultaneously performed.Results The scores of G and S in model control group and model colchicine group were significantly higher than those in normal control group( F =125.41,P =0.00; F =99.18,P =0.00).The scores of G and S in model control group were significantly higher than those in model colchicine group(P ＜0.01 ).The scores of CB1 and CB2 expressions in model control group and model colchicine group were significantly higher than those in normal control group ( F =29.27,P =0.00; F =36.99,P =0.00).The scores of CB1 and CB2 in model control group were significantly higher than those in model colchicine group( P ＜ 0.05 or P ＜ 0.01 ).There were significant relationships among scores of CB1,CB2,G and S in model control group and model colchicine group(Ps ＜0.05).As the scores of G and S became higher,the expressions of CB1 and CB2 gradually became more intensive.Conclusion The hepatic expressions of CB1 and CB2 in C57 mice with experimental cirrhosis increased significantly and have significant relationship with the grades of liver tissue inflammation and fibrosis.

OBJECTIVETo investigate the AAPH scavenging activities of 22 flavonoids and phenolic acids and 9 extracts of Chinese materia medica.

METHODThe antioxidant activities of the samples were evaluated by an oxygen radical absorbance capacity method (ORAC), at the same time, the total contents of flavonoids and phenolic the 9 herb extracts were analyzed by Folin-Ciocalteu method, and the active components were qualitatively and quantitatively analyzed by an HPLC method.

RESULTIt was found that the tea extract showed the strongest AAPH activity with the ORAC value of 4786.40 micromol x g(-1) whereas safflower demonstrated the weakest activity with the ORAC value of 784.04 micromol x g(-1). As for compounds, quercetin had the strongest AAPH activity with the ORAC value of 12.90 while ( - )-EGC had the weakest activity with the ORAC value of 2.47. A quantitative relationship was obtained to describe the AAPH scavenging activity of the herb extracts: Y = 1844.8 lnX-3577.5, r = 0.8675, where Y stands for the ORAC vaule, and X stands for the concentration of total phenolic acids.

CONCLUSIONFlavonoids and phenolic acids are the AAPH scavenging active ingredients in the Chinese herb extracts. It's a good way to study the antioxidant activity of Chinese herb extract and its chemical composition by combing ORAC method and HPLC method.

Amidines ; analysis ; Drugs, Chinese Herbal ; analysis ; Flavonoids ; analysis ; Free Radical Scavengers ; analysis ; Hydroxybenzoates ; analysis ; Materia Medica ; chemistry ; Plants, Medicinal ; chemistry