Blood compatibility evaluations of two-dimensional Ti3C2Tx nanosheets

Two-dimensional (2D) nanomaterial Ti3C2Tx is a novel biomaterial used for medical apparatus. For its application, biosafety serves as a prerequisite for their use in vivo. So far, no research has systematically reported how Ti3C2Tx interacts with various components in the blood. In this work, we evaluated the hemocompatibility of Ti3C2Tx nanosheets which we prepared by HF etching. Effects of the concentration and size of Ti3C2Tx on the morphology and hemolysis rate of human red blood cells (RBCs), the structure and conformation of plasma proteins, the complement activation, as well as in vitro blood coagulation were studied. In general, Ti3C2Tx takes on good blood compatibility, but in the case of high concentration (>30 μg/mL) and “Small size” (about 100 nm), it led to the rupture of RBCs membrane and a higher rate of hemolysis. Meanwhile, platelets and complement were inclined to be activated with the increased concentration, accompanying the changed configuration of plasma proteins dependent on concentration. Surprisingly, the presence of Ti3C2Tx did not significantly disrupt the coagulation. In vitro cell culture, the results prove that when the Ti3C2Tx concentration is as high as 60μg/mL and still has good biological safety. By establishing a fuzzy mathematical model, it was proved that the hemocompatibility of Ti3C2Tx is more concentration-dependent than size-dependent, and the hemolysis rate is the most sensitive to the size and concentration of the Ti3C2Tx. These findings provide insight into the potential use of Ti3C2Tx as biofriendly nanocontainers for biomaterials in vivo.

Compatibility of Composite Biomaterials in Sports Injury Repair

With the rapid development of sports, sports injuries have become an inevitable problem in sports. Repairing sports injuries has always been the focus of attention in the field of sports and medicine. The wide application of biomedical materials leads to the innovation and development of medical technology. It is of great significance to use them to repair sports injuries, but the current research results are not ideal. In this paper, the biocompatibility of composite biomaterials used to repair sports injuries was studied. First, the rat bone marrow mesenchymal stem cells were cultured to prepare a cell suspension. Then, the tricalcium phosphate-gelatin composite scaffold material and the collagen material were scraped into powder to make the material extract, which are, respectively, the experimental group and the control group. An apoptosis detection kit and a flow cytometer were used to detect apoptosis rate and survival rate of all samples, and a CKK-8 kit was used to detect cytotoxicity and calculate cell proliferation activity. The absorbance value was read with a microplate reader, and the coagulation performance and hemolysis rate of different groups were calculated. The experimental results showed that the cell survival rate of the experimental group was 91.41%, the early apoptosis rate was 2.81%, the stem cell proliferation activity was 0.83, and the anticoagulant performance and hemolysis rate were 64.8% and 0.28%, respectively. This indicates that although the anticoagulant performance of the tricalcium phosphate-gelatin composite scaffold is weak, its cell proliferation activity is strong, which is more suitable for cell adhesion and proliferation, and the cell apoptosis and hemolysis rate are lower. Therefore, it has better biocompatibility than a single collagen material.

Evaluation of hemolysis during storage of red blood cell concentrates processed by centrifugation and settling method by simple gravity in Burkina Faso

Background: Hemolysis is one of the red blood cell concentrates (RCCs) storage concerns. In Burkina Faso, hemolysis rate was not routinely assessed in RCCs. Our study aimed at assessing the degree of hemolysis in RCCs processed by centrifugation (centrifuged RCCs) and whole blood settling by simple gravity (Sedimented RCCs) in Burkina Faso. Methods: We conducted a cross-sectional comparative study on 46 prepared by centrifugation and 46 prepared by sedimentation, matched on their collection date and initial volume of whole blood. The hemolysis percent was measured on Days 0, 7, 14, 21, 28 and 32. Results: In the centrifuged RCCs, the hemolysis percent on D0 was 0.232% versus 0.199% for the sedimented RCCs (p = 0.046). At D32, the average hemolysis percent was 835% for the sedimented RCCs and 0.779% for the centrifuged RCCs (p = 0.042). The degree of hemolysis increased gradually between D0 and D32 with an average increase of 0.120% for centrifuged RCCs and 0.116% for sedimented RCCs. Conclusion: The degree of hemolysis at D32 in both centrifuged RCCs and sedimented RCCs falls below standards. Therefore, it necessary to revisit blood components processing procedures, focusing on the centrifugation parameters and the handling conditions.

Nanostructured Titanium for Improved Endothelial Biocompatibility and Reduced Platelet Adhesion in Stent Applications

Although coronary stents have improved the early and long-term consequences of arterial lesions, the prevention of restenosis and late stent thrombosis is key to prevent a new obstruction of the vessel. Here we aimed at improving the tissue response to stents through surface modification. For that purpose, we used two different approaches, the use of nanostructuration by electrochemical anodization and the addition of a quercitrin (QR) coating to the Ti surface. Four surfaces (Ti, NN, TiQR and NNQR) were characterized by atomic force microscopy, scanning electronic microscopy and contact angle analysis and QR content was evaluated by fluorescent staining. Cell adhesion, cytotoxicity, metabolic activity and nitric oxide (NO) production was evaluated on primary human umbilical cord endothelial cells (HUVECs). Platelet adhesion, hemolysis rate and Staphylococcus epidermidis CECT 4184 adhesion at 30 min were analyzed. Nanostructuration induced an increase on surface roughness, and QR coating decreased the contact angle. All surfaces were biocompatible, with no hemolysis rate and lower platelet adhesion was found in NN surfaces. Finally, S. epidermidis adhesion was lower on TiQR surfaces compared to Ti. In conclusion, our results suggest that NN structuration could improve biocompatibility of bare metal stents on endothelial cells and reduce platelet adhesion. Moreover, QR coating could reduce bacterial adhesion.

Kinetic parameters of complement activation in patients with paroxysmal nocturnal hemoglobinuria during eculizumab therapy

Introduction. Eculizumab inhibits the terminal steps of complement activation and is the standard treatment for paroxysmal nocturnal hemoglobinuria (PNH). Unstable complement inhibition causes “breakthrough” intravascular hemolysis and a suboptimal response to eculizumab therapy in some patients with PNH.Aim: to evaluate the stability of complement inhibition in eculizumab treatment by testing the kinetic parameters of complement activation.Materials and methods. The study included 12 PNH patients receiving long-term eculizumab therapy (median 54 months, range 4–66 months). The median age was 35 years (from 22 to 68 years), 92 % of patients were female. The median PNH clone size was 96 % of the granulocytes. The control group consisted of 12 healthy donors (age 25–60 years, women 75 %). Complement activation was evaluated immediately prior to the next eculizumab infusion, and then again after 5 and 10 days. Kinetic parameters (induction period, hemolysis rate, T50-the time required to achieve 50 % hemolysis) were recorded separately for the total complement activity and an alternative activation pathway using rabbit red blood cells (rRBC).Results. The parameters of complement activation directly before the next eculizumab administration corresponded to a marked inhibition of the overall activity of the system. The induction period was extended by 7 times compared to the control (median 180 vs 25 seconds, p < 0.0001), and the hemolysis rate was 28 times less (median 1.6 vs 45.1 × 106 rRBC/min, p < 0.0001). The T50 value exceeded the control value by 20 times (median 690 vs 35 seconds, p < 0.0001). The parameters of the alternative complement activation pathway were reduced by 2–3 times compared to the control. In one case, repeated tests revealed insuffi cient complement inhibition, which was associated with pharmacokinetic “breakthrough” hemolysis. The degree of further complement inhibition and the tendency to restore activity varied signifi cantly during dynamic testing on days 5 and 10 after eculizumab infusion.Conclusion. The results of this study demonstrate individual differences in the residual activity of complement in PNH patients receiving long-term eculizumab therapy. Testing of complement activity is necessary with a suboptimal response to eculizumab therapy and when considering therapy correction. Kinetic registration of residual complement-dependent lysis of rabbit red blood cells demonstrates a higher sensitivity than the traditional CH50 study.Conflict of interest: the authors declare no conflict of interest.Financial disclosure: the study had no sponsorship.

The Hemolysis Effect of Rotary Cutting Thrombectomy Device: The CFD and Experimental Study

Percutaneous mechanical thrombectomy (PMT) is an efficient way to treat the deep vein thrombosis (DVT). During the course of treatment, blood cell will be destroyed by the component of thrombectomy device, causing hemolysis. In this research, the computational fluid dynamics (CFD) methodology is used to investigate hemolysis effect of rotary cutting thrombectomy device. And a prototype of rotary cutting thrombectomy device is made to carry out two corresponding experiments to verify the simulation results. CFD results indicate that the hemolysis rate increases significantly with the rise of rotation speed of cutting component. The experimental results are in good consistence with the CFD results, and shows that the longer the working time, the higher the hemolysis rate. Thus a rotation speed between 5,000 rpm and 10,000 rpm can be considered reasonable. The results can be served as a helpful guidance for the design of such thrombectomy devices.

Hemolysis has no influence on routine coagulation tests in subjects without anticoagulant therapy - a referral Romanian emergency hospital laboratory experience

The aim of this study was to determine the rate of hemolyzed specimens sent to our laboratory for coagulation testing, assess the interference of hemolysis on coagulation for patients without anticoagulant therapy and to determine the reference intervals for PT, INR and aPTT for our laboratory in order to test our own limitations. Methods: To determine the hemolysis rate, 1,689 specimens were evaluated on a visual scale and with the hemolysis icterus lipemia (HYL) test on Architect c4000 instrument. 125 blood samples collected from subjects without anticoagulant therapy were hemolyzed in vitro and the PT, INR and aPTT results were compared before and after hemolysis.To determine reference intervals (RI) for PT, INR and aPTT in our population, 125 apparently healthy human subjects (according to CLSI C28-A2) were enrolled and tests were performed on Sysmex CS 2000i, using Siemens reagents. Results: Out of 1,689 samples, 9.46% were assessed as hemolyzed by the visual scale, while HYL test showed a 6.63% hemolysis rate. We found a shortening of 0.1s for PT, a diminution with 0.01 units for INR and a prolongation with 0.9s for aPTT from in vitro hemolyzed compared to non-lyzed samples. As to the reference intervals, we obtained in our laboratory versus reagents producer: for PT 9.8-13.9 s vs 9.8-12.1 s, and for aPTT 19.1-31.5s vs 23-31.9 s respectively; 28.38% more PT results and 13.44% more aPTT results were within range when we used local laboratory RI, compared to the manufacturer’s RI. Conclusions: The rate of hemolyzed coagulation samples in our laboratory is higher than the rate found in the literature. Nevertheless, for patients without anticoagulant therapy hemolyzed samples should be processed. Using our own reference interval leads to a significant reduced number of abnormal results.

A Temperature Resistant Extracts Prepared from the Perinereis aibuhitensis and Its Antioxidative Characterization

The Perinereis aibuhitensis (P. aibuhitensis), a traditional Chinese medicine, has a function of delaying senilityaccording to “Compendium of Materia Medica”. It is considered a useful animal model in antioxidant activity tests. The P. aibuhitensis has already been utilized as biochemical responses to specific pollutants and the food supply for various birds. In the present work, the extracts from P. aibuhitensis were prepared by the traditional decocting method and the biocompatibility was characterized by hemolysis and MTT tests. The materials showed no hemolytic for the hemolysis rate (lower than 0.2 %) while exhibited moderate cytotoxic effects on HUVECs (Human Umbilical Vein Endothelial Cells). In extracellular antioxidant activity against O2¯ and ·OH, the extracts from P. aibuhitensis could eliminate O2¯ and ·OH efficiently. In cellular ROS level tests, the ROS level was reduced effectively after treated with P. aibuhitensis extracts. The extracts had a potential prospect as a biological antioxidant to reduce redundant reactive oxygen species damage and great significance for humans health.