ABSTRACT
Aim To avoid the limitation of the use of cationic polyethlenimine (PEI)-complexed plasmid DNA use for in vitro or in vivo gene delivery due to its cytotoxicity and lower efficiency in the presence of serum. Methods A polyplex with decreased positive charge on the complex surface was designed. The PEI/DNA (PD) complexes coated with an anionic biodegradable polymer, alginate were prepared and their gene delivery behavior with PD was compared. Results The alginate-coated PD polyplex, where alginate: PEI: DNA [alginate: DNA, 0. 15 (w/w); PEI: DNA, N: P = 10] showed about 10 -30 fold-increased transfection efficiency compared to corresponding non-coated complexes to C3 cells in the presence of 50% serum. The surface charge of the alginate-coated complex was approximately half of that of the alginate-lacking complex. The size of alginate-coated complex was slightly smaller than that of the corresponding complex without alginate. The former complex also showed a reduced erythrocyte aggregation activity and decreased cytotoxicities to C3 cells in comparison with PD complex. Conclusion The alginate-coated PD polyplexes as a new gene delivery system can improve transfection efficiency in high serum concentration with low cytotoxicity to C3 cells.
ABSTRACT
OBJECTIVE: The aim of this study was 1) to determine the diagnostic performance of amniotic fluid white blood cell (WBC) count for the antenatal detection of intrauterine infection and 2) to identify the value in prediction of preterm birth and significant neonatal morbidity in patients with preterm premature rupture of membranes. METHODS: Transabdominal amniocentesis was done in 255 singleton pregnancies with preterm premature rupture of membranes before 36 weeks of gestational age. Amniotic fluid was cultured for aerobic and anaerobic bacteria and mycoplasmas. Receiver-operator characteristic curve, survival analysis and logistic regression were used for statistical analysis. RESULTS: 1) Prevalence of positive amniotic fluid culture was 19.6% (50/255). Amniotic fluid WBC count was higher in the patients with positive amniotic fluid culture than those with negative amniotic fluid culture (median 269 [0-19764] cells/mm3 vs median 2 [0-7956] cells/mm3, p or = 20 cells/mm3) had sensitivity of 74%, specificity of 74%, positive predictive value of 41% and negative predictive value of 92% for the positive result of amniotic fluid culture. 3) An increased amiotic fluid WBC was strongly associated with shorter amniocentesis-to-delivery interval even after adjustment of gestational age at amniocentesis(hazard ratio 3.2736, p<0.0001). 4) Amniotic fluid WBC count was higher in patients with significant neonatal morbidity or congenital neonatal infectious morbidity than those without these (p<0.001 and p<0.005 respectively). 5) Patients with increased amniotic fluid WBC count had higher incidence of significant neonatal morbidity and congenital neonatal infectious morbidity than those with low amniotic fluid WBC count and the association between amniotic fluid WBC and significant neonatal morbidity was statistically significant after adjustment of gestational age at amniocentesis (OR 3.3649, p<0.0001). CONCLUSION: Amniotic fluid WBC count is of value in antenatal diagnosis of intrauterine infection and prediction of maternal and neonatal outcomes in patients with preterm premature rupture of membranes.