Switching from abacavir to tenofovir disoproxil fumarate is associated with rises in soluble glycoprotein VI, suggesting changes in platelet-collagen interactions.

OBJECTIVES: Altered platelet function has been proposed as an underlying mechanism to explain increased risk of myocardial infarction in people living with HIV associated with use of the nucleoside reverse transcriptase inhibitor abacavir (ABC). We aimed to examine changes in platelet biomarkers in people living with HIV switching from ABC. METHODS: In a prospective, 48-week substudy of virally suppressed HIV-1-positive subjects randomized to remain on ABC/lamivudine (ABC/3TC) or switch to tenofovir disoproxil fumarate/emtricitabine, we measured soluble glycoprotein VI (sGPVI), soluble P-selectin, soluble CD40 ligand and von Willebrand factor in plasma collected over time and assessed differences using mixed effect models. RESULTS: Of 312 randomized participants, 310 were included in the analysis. Mean (SD) age 46.4 (9.3) years, 262 (85%) men and 201 (65%) white. At baseline, there was no significant between-group difference in sGPVI [tenofovir disoproxil fumarate/emtricitabine 3.75 (0.25) versus ABC/3TC 3.61 (0.22) ng/ml, P = 0.69]. Greater increases in sGPVI from baseline to week 48 occurred in those switched from ABC/3TC (effect size +0.57 ng/ml; 95% confidence interval, 0.2-0.94; P = 0.003). There was no significant baseline difference or change overtime in soluble P-selectin, soluble CD40 ligand or von Willebrand factor between groups. CONCLUSION: The significant increases in sGPVI that occur with a switch from ABC/3TC are suggestive of changes in platelet function centred on platelet/collagen interactions and potentially represent an underlying mechanism to explain increased risk of myocardial infarction with ABC.</p

Predicted linear B-cell epitopes in ZNF proteins.

<p>Predicted linear B-cell epitopes in ZNF proteins.</p

Relative OD autoantibody signals detected in CRC and NCC sera by indirect ELISA.

<p>Zinc finger proteins (A) ZNF346, (B) ZNF638, (C) ZNF700 and (D) ZNF768 were used as capture antigens. Black line represents the average of relative ODs (optical density) within each patient cohort. Red line represents ELISA cut-offs calculated as the average of NCC relative OD values +2SD. CRC: colorectal cancer, NCC: non-cancer control.</p

Zinc finger protein sequence overlap and similarities.

<p>*Selection criteria: Identity >50%, exact match ≥5 ≤20 amino acids</p><p>**One ZNF346 epitope repeated 12 times in ZNF700</p><p>Zinc finger protein sequence overlap and similarities.</p

ZNF-specific autoantibodies and colorectal cancer prognosis.

<p>Kaplan-Meier analysis revealed that presence of autoantibodies specific to zinc finger proteins (A) ZNF346, (B) ZNF638, (C) ZNF700, (D) ZNF768 and (E) panel of all four ZNFs combined does not predict survival in colorectal cancer.</p

Clinicopathological details of patient cohort.

<p>* Standard Deviation</p><p>Clinicopathological details of patient cohort.</p

Frequency of autoantibodies to zinc finger proteins in patients.

<p>* Positive for autoantibodies in non-cancer controls (NCC, n = 35)</p><p>** Positive for autoantibodies in colorectal cancer patients (CRC, n = 96)</p><p>Frequency of autoantibodies to zinc finger proteins in patients.</p

Self-Powered Microfluidic Device for Rapid Assay of Antiplatelet Drugs

We report the development of a microfluidic device for the rapid assay in whole blood of interfacial platelet–protein interactions indicative of the efficacy of antiplatelet drugs, for example, aspirin and Plavix, two of the world’s most widely used drugs, in patients with cardiovascular disease (CVD). Because platelet adhesion to surface-confined protein matrices is an interfacial phenomenon modulated by fluid shear rates at the blood/protein interface, and because such binding is a better indicator of platelet function than platelet self-aggregation, we designed, fabricated, and characterized the performance of a family of disposable, self-powered microfluidic chips with well-defined flow and interfacial shear rates suitable for small blood volumes (≤200 μL). This work demonstrates that accurate quantification of cell adhesion to protein matrices, an important interfacial biological phenomenon, can be used as a powerful diagnostic tool in those with CVD, the world’s leading cause of death. To enable such measurements, we developed a simple technique to fabricate single-use self-powered chips incorporating shear control (SpearChips). These parallel-plate flow devices integrate on-chip vacuum-driven blood flow, using a predegassed elastomer component to obviate active pumping, with microcontact-printed arrays of 6-μm-diameter fluorescently labeled fibrinogen dots on a cyclic olefin polymer base plate as a means to quantitatively count platelet–protein binding events. The use of SpearChips to assess in whole blood samples the effects of GPIIb/IIIa and P2Y₁₂ inhibitors, two important classes of “antiplatelet” drugs, is reported

Identification of the physical-chemical properties that modulate the nanoparticles aggregation in blood

Inorganic materials are receiving significant interest in medicine given their usefulness for therapeutic applications such as targeted drug delivery, carriers of active pharmaceutical and medical imaging. However, the poor knowledge of the side effects related to their use is an obstacle to their clinical translation. For the molecular drug development, safe-by-design has become as a novel pharmaceutical strategy that allows a reduction of the costs and an acceleration of the translation of research to market. In the case of materials, the application of such approaches is hampered by a poor knowledge of how the physical and chemical properties of the material trigger biological response. Hemocompatibility is a crucial factor for those materials that are intended for medical applications. In particular, the formation of agglomerates is a serious side effect that may induce occlusion of blood vessels and thrombotic events. Additionally, nanoparticles can interfere with the coagulation cascades where they have been reported to induce both pro- and anti-coagulant properties where their properties like size, shape and surface charge have been see to be critical parameters.   Here, we developed two sets of tailored carbon and silica nano/submicron-particles with three different sizes (100-500 nm) with the purpose of investigating the role of surface curvature and chemistry on platelet aggregation, activation and adhesion. We show that that large carbon nanoparticles, but not small carbon nanoparticles or silica nanoparticles, have a strong tendency to form aggregates both in plasma and blood, as a consequence of the formation of a protein corona and not of platelets activation. Substantial differences were found in the composition of the protein corona depending upon the chemical nature of the nanoparticles, while the surface curvature plays a minor role. On the other hand, coagulation proteins were abundant in the corona of both silica and carbon nanoparticles.  The results presented herein suggest that vessel occlusion and formation of thrombi in vivo may occur through independent mode of action (MoA), differently affected by the physico-chemical properties of the materials

Self-Powered Microfluidic Device for Rapid Assay of Antiplatelet Drugs

We report the development of a microfluidic device for the rapid assay in whole blood of interfacial platelet–protein interactions indicative of the efficacy of antiplatelet drugs, for example, aspirin and Plavix, two of the world’s most widely used drugs, in patients with cardiovascular disease (CVD). Because platelet adhesion to surface-confined protein matrices is an interfacial phenomenon modulated by fluid shear rates at the blood/protein interface, and because such binding is a better indicator of platelet function than platelet self-aggregation, we designed, fabricated, and characterized the performance of a family of disposable, self-powered microfluidic chips with well-defined flow and interfacial shear rates suitable for small blood volumes (≤200 μL). This work demonstrates that accurate quantification of cell adhesion to protein matrices, an important interfacial biological phenomenon, can be used as a powerful diagnostic tool in those with CVD, the world’s leading cause of death. To enable such measurements, we developed a simple technique to fabricate single-use self-powered chips incorporating shear control (SpearChips). These parallel-plate flow devices integrate on-chip vacuum-driven blood flow, using a predegassed elastomer component to obviate active pumping, with microcontact-printed arrays of 6-μm-diameter fluorescently labeled fibrinogen dots on a cyclic olefin polymer base plate as a means to quantitatively count platelet–protein binding events. The use of SpearChips to assess in whole blood samples the effects of GPIIb/IIIa and P2Y₁₂ inhibitors, two important classes of “antiplatelet” drugs, is reported