METHODS: Oligo, low, medium and high molecular weight chitosan nanoparticles were prepared by nanospray drying technique. These nanoparticles were incubated with alveolar macrophages in vitro and had model drug sodium fluorescein added into the same cell culture. The diffusion characteristics of sodium fluorescein and nanoparticle behavior were investigated using fluorescence microscopy, scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques.
RESULTS: The oligochitosan nanoparticles enabled macrophage membrane fluidization with the extent of sodium fluorescein entry into macrophages being directly governed by the nanoparticle loading. Using nanoparticles made of higher molecular weight chitosan, sodium fluorescein permeation into macrophages was delayed due to viscous chitosan diffusion barrier at membrane boundary.
CONCLUSION: Macrophage-chitosan nanoparticle interaction at membrane interface dictates drug migration into cellular domains.
OBJECTIVES: To compare the effectiveness of anticoagulant therapies for the treatment of deep vein thrombosis in pregnancy. The anticoagulant drugs included are UFH, low molecular weight heparin (LMWH) and warfarin.
SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2010) and reference lists of retrieved studies.
SELECTION CRITERIA: Randomised controlled trials comparing any combination of warfarin, UFH, LMWH and placebo in pregnant women.
DATA COLLECTION AND ANALYSIS: We used methods described in the Cochrane Handbooks for Systemic Reviews of Interventions for assessing the eligibility of studies identified by the search strategy. A minimum of two review authors independently assessed each study.
MAIN RESULTS: We did not identify any eligible studies for inclusion in the review.We identified three potential studies; after assessing eligibility, we excluded all three as they did not meet the prespecified inclusion criteria. One study compared LMWH and UFH in pregnant women with previous thromboembolic events and, for most of these women, anticoagulants were used as thromboprophylaxis. There were only three women who had a thromboembolic event during the current pregnancy and it was unclear whether the anticoagulant was used as therapy or prophylaxis. We excluded one study because it included only women undergoing caesarean birth. The third study was not a randomised trial.
AUTHORS' CONCLUSIONS: There is no evidence from randomised controlled trials on the effectiveness of anticoagulation for deep vein thrombosis in pregnancy. Further studies are required.