Microrheological effects of drag-reducing polymers in vitro and in vivo

Kameneva, Marina V.

doi:10.1016/j.ijengsci.2012.03.014

Cited by 45 publications

(41 citation statements)

References 46 publications

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“…This leads to reduction of pressure gradients across the arterial system and an increase in the precapillary blood pressure enhancing capillary perfusion which has been demonstrated in vitro and confirmed in vivo. 37 Another recently discovered mechanism is the ability of DRP to reduce the near-wall cell-free layer (CFL), 38 which is actually RBC free layer, that naturally exists in microvessels with diameters below 300 lm 39 and which was proposed to be an important factor in the regulation of hemodynamics. Reduction in the near-wall cellfree layer increases wall shear stresses promoting release of nitric oxide and vasodilation.…”

Section: Mechanisms Of Drp Effectsmentioning

confidence: 99%

“…41 Reduction of plasma skimming increases the number of RBC flowing through capillaries and thereby increases oxygen delivery to the tissues and the efficiency of gas exchange. 38 These effects of DRP could explain the increased capillary density in diabetic animals, 42 increased myocardial perfusion and animal survival after induced myocardial infarction, 43 and a significant increase in tissue perfusion and animal survival rate after exposure to lethal hemorrhage, and others. 38 Increased in near-wall shear stress and occupation of the near-wall space by RBC, due to presence of DRP in the blood, may explain the significant reduction in the inflammatory reaction to implants observed in animals 28 potentially due to reduction of the near-wall rolling leukocytes, their attachment to vessel walls, and extravasation.…”

Section: Mechanisms Of Drp Effectsmentioning

confidence: 99%

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Rheological effects of drag-reducing polymers improve cerebral blood flow and oxygenation after traumatic brain injury in rats

Bragin

Kameneva

Bragina

et al. 2016

J Cereb Blood Flow Metab

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Cerebral ischemia has been clearly demonstrated after traumatic brain injury (TBI); however, neuroprotective therapies have not focused on improvement of the cerebral microcirculation. Blood soluble drag-reducing polymers (DRP), prepared from high molecular weight polyethylene oxide, target impaired microvascular perfusion by altering the rheological properties of blood and, until our recent reports, has not been applied to the brain. We hypothesized that DRP improve cerebral microcirculation and oxygenation after TBI. DRP were studied in healthy and traumatized rat brains and compared to saline controls. Using in-vivo two-photon laser scanning microscopy over the parietal cortex, we showed that after TBI, nanomolar concentrations of intravascular DRP significantly enhanced microvascular perfusion and tissue oxygenation in peri-contusional areas, preserved blood-brain barrier integrity and protected neurons. The mechanisms of DRP effects were attributable to reduction of the near-vessel wall cell-free layer which increased near-wall blood flow velocity, microcirculatory volume flow, and number of erythrocytes entering capillaries, thereby reducing capillary stasis and tissue hypoxia as reflected by a reduction in NADH. Our results indicate that early reduction in CBF after TBI is mainly due to ischemia; however, metabolic depression of contused tissue could be also involved.

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Section: Mechanisms Of Drp Effectsmentioning

confidence: 99%

Section: Mechanisms Of Drp Effectsmentioning

confidence: 99%

Rheological effects of drag-reducing polymers improve cerebral blood flow and oxygenation after traumatic brain injury in rats

Bragin

Kameneva

Bragina

et al. 2016

J Cereb Blood Flow Metab

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show abstract

“…Increased tissue perfusion without a significant increase in the arterial blood pressure is extremely important for resuscitation after severe bleeding, since an increase in blood pressure may induce secondary bleeding (Kameneva 2012). We found that augmentations were observed in both the RS group and PEO group with regard to the MAP level after resuscitation, but the differences between the PEO group and RS group were not statistically significant (p > 0.05, Fig.…”

Section: Discussionmentioning

confidence: 66%

“…These properties allow them to reduce turbulent flow resistance, thereby increasing flow rate at a constant driving pressure (Kameneva 2012). DRPs have been widely used in the biomedical domain since the 1980s, mainly because of their ameliorative effects on intravascular hemodynamic and hemorrheological properties.…”

Section: Introductionmentioning

confidence: 99%

Protective effects of polyethylene oxide on the vascular and organ function of rats with severe hemorrhagic shock

Huang

Dong

2015

Can. J. Physiol. Pharmacol.

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This study examined the effects of polyethylene oxide (PEO) on the survival rate, hemodynamics, blood gas indexes, lactic acid levels, microcirculation, and inflammatory cytokine levels in rats subjected to severe hemorrhagic shock. The shocked rats were resuscitated with either Ringer's lactate solution or 20 ppm of PEO in Ringer's lactate solution for 1 h. It was found that infusion of PEO effectively improved the survival, metabolic acidosis, oxygen delivery, hyperlactacidemia, tissue perfusion, and inflammatory responses of rats subjected to hemorrhagic shock. In addition, we found, for the first time, that PEO showed protective effects on hepatic and renal injury, as evidenced by the significant decreases in the elevated levels of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine caused by shock induction after infusion of PEO (p < 0.05, 60 min post-resuscitation by comparison with pre-resuscitation). All of these findings indicate that PEO exhibits strong therapeutic effects under conditions of severe hemorrhagic shock,which also provides theoretical and experimental bases for the clinical use of PEO.

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“…These long, molecules of DRPs, dissolved in blood plasma are thought to provide a “liquid scaffold” reducing pressure loss in small arteries and arterioles by organizing blood flow and suppressing flow separations and vortices at vascular branch points [5, 14–18]. In addition, DRP reduce “plasma skimming” at vessel bifurcations, which increases red blood cells (RBC) flow in capillaries [14, 16]. The increase in the precapillary pressure promoting an increase in the density of functioning capillaries and the elimination of capillary stasis caused by ischemia or other pathological conditions [14].…”

Section: Discussionmentioning

confidence: 99%

Drag-Reducing Polymer Enhances Microvascular Perfusion in the Traumatized Brain with Intracranial Hypertension

Bragin

Thomson

Bragina

et al. 2016

Acta Neurochirurgica Supplement

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SUMMARY Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood soluble non-toxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and limb, but have not yet been studied in the brain. Recently, we demonstrated that that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using the in-vivo 2-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow and, as a result, reduced tissue hypoxia in both un-traumatized and traumatized rat brains at high ICP. Our study suggests that DRP could be an effective treatment for improving microvascular flow in brain ischemia caused by high ICP after TBI.

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Microrheological effects of drag-reducing polymers in vitro and in vivo

Cited by 45 publications

References 46 publications

Rheological effects of drag-reducing polymers improve cerebral blood flow and oxygenation after traumatic brain injury in rats

Rheological effects of drag-reducing polymers improve cerebral blood flow and oxygenation after traumatic brain injury in rats

Protective effects of polyethylene oxide on the vascular and organ function of rats with severe hemorrhagic shock

Drag-Reducing Polymer Enhances Microvascular Perfusion in the Traumatized Brain with Intracranial Hypertension

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