VEGF (Vascular Endothelial Growth Factor) Functionalized Magnetic Beads in a Microfluidic Device to Improve the Angiogenic Balance in Preeclampsia.

Preeclampsia is a hypertensive pregnancy disease associated with a massive increase in sFlt-1 (soluble form of the vascular endothelial growth factor 1) in the maternal circulation, responsible for angiogenic imbalance and endothelial dysfunction. Pilot studies suggest that extracorporeal apheresis may reduce circulating sFlt-1 and prolong pregnancy. Nonspecific apheresis systems have potential adverse effects because of the capture of many other molecules. Our concept is based on a specific and competitive apheresis approach using VEGF (vascular endothelial growth factor) functionalized magnetic beads to capture sFlt-1 while releasing endogenous PlGF (placental growth factor) to restore a physiological angiogenic balance. Magnetic beads were functionalized with VEGF to capture sFlt-1. Experiments were performed using PBS, conditioned media from human trophoblastic cells, and human plasma. The proof of concept was validated in dynamic conditions in a microfluidic device as an approach mimicking real apheresis. Magnetic beads were functionalized with VEGF and characterized to evaluate their surface ligand density and recognition capabilities. VEGF-coated magnetic beads proved to be an efficient support in capturing sFlt-1 and releasing PlGF. In static conditions, sFlt-1 concentration decreased by 33±13%, whereas PlGF concentration increased by 27±10%. In dynamic conditions, the performances were improved, with 40% reduction of sFlt-1 and up to 2-fold increase of free PlGF. The sFlt-1/PlGF ratio was reduced by 63% in the plasma of preeclamptic patients. Apheresis was also associated with VEGF release. A ligand-based approach using VEGF-coated beads is an effective approach to the capture of sFlt-1 and the release of endogenous PlGF. It offers new perspectives for the treatment of preeclampsia.

Association Between Planned Cesarean Delivery and Neonatal Mortality and Morbidity in Twin Pregnancies.

OBJECTIVE: To evaluate the association between the planned mode of delivery and neonatal mortality and morbidity in an unselected population of women with twin pregnancies. METHODS: The JUmeaux MODe d'Accouchement (JUMODA) study was a national prospective population-based cohort study. All women with twin pregnancies and their neonates born at or after 32 weeks of gestation with a cephalic first twin were recruited in 176 maternity units in France from February 2014 to March 2015. The primary outcome was a composite of intrapartum mortality and neonatal mortality and morbidity. Comparisons were performed according to the planned mode of delivery, planned cesarean or planned vaginal delivery. The primary analysis to control for potential indication bias used propensity score matching. Subgroup analyses were conducted, one according to gestational age at delivery and one after exclusion of high-risk pregnancies. RESULTS: Among 5,915 women enrolled in the study, 1,454 (24.6%) had planned cesarean and 4,461 (75.4%) planned vaginal deliveries, of whom 3,583 (80.3%) delivered both twins vaginally. In the overall population, composite neonatal mortality and morbidity was increased in the planned cesarean compared with the planned vaginal delivery group (5.2% compared with 2.2%; odds ratio [OR] 2.38, 95% confidence interval [CI] 1.86-3.05). After matching, neonates born after planned cesarean compared with planned vaginal delivery had higher composite neonatal mortality and morbidity rates (5.3% compared with 3.0%; OR 1.85, 95% confidence interval 1.29-2.67). Differences in composite mortality and morbidity rates applied to neonates born before but not after 37 weeks of gestation. Multivariate and subgroup analyses after exclusion of high-risk pregnancies found similar trends. CONCLUSION: Planned vaginal delivery for twin pregnancies with a cephalic first twin at or after 32 weeks of gestation was associated with low composite neonatal mortality and morbidity. Moreover, planned cesarean compared with planned vaginal delivery before 37 weeks of gestation might be associated with increased composite neonatal mortality and morbidity.

Impairment in ischemia-induced neovascularization in diabetes: bone marrow mononuclear cell dysfunction and therapeutic potential of placenta growth factor treatment.

Mechanisms that hinder ischemia-induced neovascularization in diabetes remain poorly understood. We hypothesized that endogenous bone marrow mononuclear cell (BM-MNC) dysfunction may contribute to the abrogated postischemic revascularization reaction associated with diabetes. We first analyzed the effect of diabetes (streptozotocin, 40 mg/kg) on BM-MNC pro-angiogenic potential in a model of surgically induced hindlimb ischemia. In nondiabetic animals, transplantation of BM-MNCs isolated from nondiabetic animals raised the ischemic/nonischemic angiographic score, capillary number, and blood flow recovery by 1.8-, 2.7-, and 2.2-fold, respectively, over that of PBS-injected nondiabetic animals (P < 0.05). Administration of diabetic BM-MNCs also improved the neovascularization reaction in ischemic hindlimbs of nondiabetic mice but to a lesser extent from that observed with nondiabetic BM-MNC transplantation. In diabetic mice, injection of nondiabetic BM-MNCs was still more efficient than that of diabetic BM-MNCs. Such BM-MNC dysfunction was associated with the impairment of diabetic BM-MNC capacity to differentiate into endothelial progenitor cells (EPCs) in vitro and to participate in vascular-like structure formation in a subcutaneous Matrigel plug. Placenta growth factor (PlGF) administration improved by sixfold the number of EPCs differentiated from diabetic BM-MNCs in vitro and enhanced ischemic/nonischemic angiographic score, capillary number and blood flow recovery by 1.9-, 1.5- and 1.6-fold, respectively, over that of untreated diabetic animals (P < 0.01). Endogenous BM-MNC pro-angiogenic potential was affected in diabetes. Therapeutic strategy based on PlGF administration restored such defects and improved postischemic neovascularization in diabetic mice.

Interleukin-18/interleukin-18 binding protein signaling modulates ischemia-induced neovascularization in mice hindlimb.

Identification of factors that may stimulate ischemia-induced neovascularization without increasing atherosclerotic plaque progression is of major therapeutic importance. We hypothesized that interleukin-18 binding protein (IL-18BP), a major antiinflammatory protein with plaque-stabilizing activities, may affect the neovascularization in mice ischemic hindlimb. Ischemia was produced by artery femoral occlusion in mice that were subjected to in vivo intramuscular electrotransfer of either an empty plasmid or a murine IL-18BP plasmid. Angiographic score, capillary density (CD31 staining), and laser Doppler perfusion data at day 28 showed significant improvement in ischemic/nonischemic leg ratio by respectively 1.6-, 1.4-, and 1.5-fold in IL-18BP-treated mice compared with controls (P<0.01). This was associated with a significant 2-fold increase in both vascular endothelial growth factor (VEGF) and phospho-Akt protein content in the ischemic hindlimb of IL-18BP-treated mice (P<0.05). Similar results were obtained in IL-18-deficient mice. Because bone marrow-derived endothelial progenitor cells (BM-EPCs) are involved in postnatal vasculogenesis, EPCs were isolated and cultivated from bone marrow mononuclear cells. IL-18BP treatment led to a significant 1.8-fold increase in the percentage of BM-EPCs characterized as cells positive for both AcLDL-Dil and von Willebrand factor (P<0.001). In conclusion, IL-18BP stimulates ischemia-induced neovascularization in association with an activation of VEGF/Akt signaling and an increase in BM-EPCs mobilization and differentiation. Our findings strongly suggest a major antiangiogenic role of endogenous IL-18 in postischemic injury.