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Biology subjects

Anagnostakou, V.

Publications and source records attributed to Anagnostakou, V..

2 recordsLinked to original sources

Development of a clot-adhesive coating to improve the performance of thrombectomy devices

BackgroundThe first-pass complete recanalization by mechanical thrombectomy (MT) for the treatment of stroke remains limited due to the poor integration of the clot within current devices. Aspiration can help retrieval of the main clot but fails to prevent secondary embolism in the distal arterial territory. The dense meshes of extracellular DNA, recently described in stroke-related clots, might serve as an anchoring platform for MT devices. ObjectiveEvaluate the potential of DNA reacting surface to aid the retention of the main clot as well as of its small fragments within the thrombectomy device and improve the potential of MT procedures. MethodsDevice-suitable alloy experimental samples were coated with 15 different compounds and contacted with extracellular DNA or with human peripheral whole blood, to compare their binding to DNA versus flowing blood elements, in vitro. Clinical-grade MT devices were coated with two selected compounds and evaluated in functional bench tests aiming to studying clot retrieval and distal emboli release, concomitant with contact aspiration, using an M1 occlusion model. ResultsBinding properties of samples coated with all compounds were increased for DNA ({approx} 3-fold) and decreased ({approx} 5-fold) for blood elements, essentially platelet, as compared to the bare alloy samples, in vitro. Functional testing showed that surface modification with DNA-binding compounds improved clot retrieval and significantly reduced secondary embolism during experimental recanalization of occluded artery 3D model by thrombectomy procedures. ConclusionOur results suggest that device coating with DNA-binding compounds can considerably improve the outcome of MT procedures in stroke patients. What is already known on this topic - New mechanical thrombectomy device are being improved on the conformation and shape to increase the interaction clot on the physical point of view. However, none interact specifically with the structure or composition of the clot. What this study adds - The design of a chemical surface modification of the device opens the way for a specific targeting tool to increase the interaction with the clot on the molecular level. How this study might affect research, practice or policy - This new surface modification, which can be applied to all commercially available mechanical thrombectomy devices, leads to a decrease in secondary embolization which cannot and is not monitored during the procedure and responsible for new territory damage.

bioengineering↗

Blood oxygenation-level dependent cerebrovascular reactivity imaging as strategy to monitor CSF-hemoglobin toxicity

PurposeCell-free hemoglobin in the cerebrospinal fluid (CSF-Hb) may be one of the main drivers of secondary brain injury after aneurysmal subarachnoid hemorrhage. Haptoglobin scavenging of CSF-Hb has been shown to mitigate cerebrovascular disruption. Using digital subtraction angiography (DSA) and blood oxygenation-level dependent cerebrovascular reactivity imaging (BOLD-CVR) the aim was to assess the acute toxic effect of CSF-Hb on cerebral blood flow and autoregulation, as well as to test the protective effects of haptoglobin. MethodsDSA imaging was performed in eight anesthetized and ventilated sheep (mean weight: 80.4 kg) at baseline, 15, 30, 45 and 60 minutes after infusion of hemoglobin (Hb) or co-infusion with haptoglobin (Hb:Haptoglobin) into the left lateral ventricle. Additionally, 10 ventilated sheep (mean weight: 79.8 kg) underwent BOLD-CVR imaging to assess the cerebrovascular reserve capacity. ResultsDSA imaging did not show a difference in mean transit time or cerebral blood flow. Wholebrain BOLD-CVR compared to baseline decreased more in the Hb group after 15 minutes (Hb vs Hb:Haptoglobin: -0.03 {+/-}0.01 vs -0.01 {+/-}0.02) and remained diminished compared to Hb:Haptoglobin group after 30 minutes (Hb vs Hb:Haptoglobin: -0.03 {+/-}0.01 vs 0.0 {+/-}0.01), 45 minutes (Hb vs Hb:Haptoglobin: -0.03 {+/-}0.01 vs 0.01 {+/-}0.02) and 60 minutes (Hb vs Hb:Haptoglobin: -0.03 {+/-}0.02 vs 0.01 {+/-}0.01). ConclusionIt is demonstrated that CSF-Hb toxicity leads to rapid cerebrovascular reactivity impairment, which is blunted by haptoglobin co-infusion. BOLD-CVR may therefore be further evaluated as a monitoring strategy for CSF-Hb toxicity after aSAH.

neuroscience↗