Blood Compatibility Tests Research Articles

Novel Biocompatible Zr-Based Alloy with Low Young's Modulus and Magnetic Susceptibility for Biomedical Implants.

The microstructure, mechanical properties, magnetic susceptibility, electrochemical corrosion performance, in vitro cell compatibility and blood consistency of Zr-16Nb-xTi (x = 0, 4, 8, 12 and 16 wt.%) materials were investigated as potential materials for biomedical implants. X-ray diffraction (XRD) and Transmission electron microscopy (TEM) analyses revealed the secondary phase martensite α’ formed during the quenching process. The phase composition contained metastable β and martensite α’, resulting from Ti addition. These phase constitutions were the main causes of a low Young’s modulus and magnetic susceptibility. The in vitro cytocompatibility analysis illustrated that the MG63 cells maintained high activity (from 91% to 97%) after culturing in Zr-16Nb-xTi extraction media for 12 days due to the high internal biocompatibility of Zr, Nb and Ti elements, as well as the optimal corrosion resistance of Zr-16Nb-xTi. On the basis of Inductively coupled plasma optical emission spectrometry (ICP-OES) ion release studies, the concentration of Zr, Nb and Ti was noted to reach the equipment detective limit of 0.001 mg/L, which was much lower than pure Ti. With respect to the corrosion behavior in Hank’s solution, Zr-16Nb-16Ti displayed superior properties, possessing the lowest corrosion current density and widest passivation region, attributed to the addition of Ti. The blood compatibility test illustrated that the Zr-16Nb-xTi materials were nonhemolytic, and the platelets maintained a spherical shape, with no aggregation or activation on Zr-16Nb-xTi. Overall, Ti addition has obvious effects on the developed Zr-16Nb-xTi alloys, and Zr-16Nb-4Ti exhibited low magnetic susceptibility, low modulus, good biocompatibility and proper corrosion properties, demonstrating the potential of use as implant biomaterials.

Design and characterization of a novel pH-sensitive biocompatible and multifunctional nanocarrier for in vitro paclitaxel release

Breast cancer is one of the main reasons of women's mortality. A novel ternary combination of ZnAl-layered double hydroxides (LDH), cobalt ferrite (CoFe2O4) and N-graphene quantum dots (N-GQDs) proposes a pH-sensitive multifunctional nanocomposite that can improve therapeutic features of each compound; this is a notable strategy to make biocompatible materials with unique properties for paclitaxel (PTX) delivery in breast cancer cells. For proving the surface modification process of materials, electrochemical techniques including cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were carried out. By coating PEG on the surface of the N-GQDs/CoFe2O4/LDH, it developed a drug delivery system with low toxicity, an excellent encapsulation efficiency 88.4%, drug loading capacity of ca. 31%, and slow and sustained release behavior (9% after 72 h) under normal physiological conditions. Besides, a high drug release (~69%) at low-pH as a model of the extracellular tumor environment indicated a pH-sensitive release behavior. Moreover, cell viability assay proved the negligible cytotoxicity on normal cells (L929) and the improved growth inhibition effect of PTX/N-GQDs/CoFe2O4/LDH nanocarrier on MCF7 cancer cells. Blood compatibility test values with respect to red blood cell aggregation (RBC), coagulation prothrombin time (PT), activated partial thromboplastin time (APTT), and complement activation (C3 and C4 levels) remained within normal ranges without toxicity effect on RBCs and complement factors. Overall, this novel designed PTX/N-GQDs/CoFe2O4/LDH nanocarrier with tremendously biocompatible, slow-release and pH-dependent features could be considered as a theranostic candidate for various anticancer drugs delivery and cancer therapy.

Preparation of phospholipid-based polycarbonate urethanes for potential applications of blood-contacting implants.

Polyurethanes are widely used in interventional devices due to the excellent physicochemical property. However, non-specific adhesion and severe inflammatory response of ordinary polyurethanes may lead to severe complications of intravenous devices. Herein, a novel phospholipid-based polycarbonate urethanes (PCUs) were developed via two-step solution polymerization by direct synthesis based on functional raw materials. Furthermore, PCUs were coated on biomedical metal sheets to construct biomimetic anti-fouling surface. The results of stress–strain curves exhibited excellent tensile properties of PCUs films. Differential scanning calorimetry results indicated that the microphase separation of such PCUs polymers could be well regulated by adjusting the formulation of chain extender, leading to different biological response. In vitro blood compatibility tests including bovine serum albumin adsorption, fibrinogen adsorption and denaturation, platelet adhesion and whole-blood experiment showed superior performance in inhibition non-specific adhesion of PCUs samples. Endothelial cells and smooth muscle cells culture tests further revealed a good anti-cell adhesion ability. Finally, animal experiments including ex vivo blood circulation and subcutaneous inflammation animal experiments indicated a strong ability in anti-thrombosis and histocompatibility. These results high light the strong anti-adhesion property of phospholipid-based PCUs films, which may be applied to the blood-contacting implants such as intravenous catheter or antithrombotic surface in the future.

Investigation of air plasma generated by surface microdischarge for decellularized porcine aortic valve leaflets modification

AbstractIn this study, the surface microdischarge (SMD) device was used to modify the mechanical properties of decellularized porcine aortic valve leaflets (DPAVL). It was found that SMD treatment under NOx mode considerably improved the ultimate tensile strength and the Young's modulus of DPAVL, whereas treatment under O3 mode had no effect. The absorbance band peak at ~1,375 cm−1, measured by Fourier‐transform infrared spectrometer, increased with treatment time in the freeze‐dried DPAVL group under NOx mode treatment. The microstructure was not destroyed and blood compatibility test showed no toxicity. The reaction between plasma‐activated species and the DPAVL and the pH change, other than temperature/UV irradiation, plays a major role. All of the results indicate that cold atmospheric plasma treatment seems to be a potential alternative for DPAVL modification.

"Whatever Works": Innovations in the Treatment of Hemophilia in the United States 1783-1950.

Treatment of the bleeding disorder hemophilia in the nineteenth century was empirical, based on clinical experience. Medications, transfusions of human or animal blood, and injections of blood sera were utilized in an attempt to halt life-threatening hemorrhages. After 1900, the application of clinical laboratory science facilitated the utilization of anti-coagulated blood and donor blood compatibility tests for safer emergency transfusions. But repeated transfusions produced blood incompatibility that limited future utilization. Investigation of hormones and snake venom as coagulants appeared hopeful during the 1930s, but plasma globulin research during World War II resulted in the isolation of antihemophilic factors that promptly reduced hemorrhage. Their application to bleeding episodes resulted in a more normal life for hemophiliacs after 1950.

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study.

Cuttlefish bones are an inexpensive source of calcium carbonate, which are produced in large amounts by the marine food industry, leading to environmental contamination and waste. The nontoxicity, worldwide availability and low production cost of cuttlefish bone products makes them an excellent calcium carbonate precursor for the fabrication of hydroxyapatite. In the present study, a novel oil-bath-mediated precipitation method was introduced for the synthesis of hydroxyapatite (Hap) nanorods using cuttlefish bone powder as a precursor (CB-Hap NRs). The obtained CB-Hap NRs were investigated using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) techniques to evaluate their physicochemical properties. The crystallite size (20.86 nm) obtained from XRD data and the elemental analysis (Ca/P molar ratio was estimated to be 1.6) showed that the Hap NRs are similar to that of natural human bone (≈1.67). Moreover, the FTIR data confirmed the presence of phosphate as a functional group and the TGA data revealed the thermal stability of Hap NRs. In addition, the antibacterial study showed a significant inhibitory effect of CB-Hap NRs against S. aureus (zone of inhibition – 14.5 ± 0.5 mm) and E. coli (13 ± 0.5 mm), whereas the blood compatibility test showed that the CB-Hap NRs exhibited a concentration-mediated hemolytic effect. These biogenic CB-Hap NRs with improved physicochemical properties, blood compatibility and antibacterial efficacy could be highly beneficial for orthopedic applications in the future.

Resolving crossmatch incompatibility due to daratumumab in multiple myeloma

Daratumumab (DARA) is an anti-CD38 monoclonal antibody which has promising results in relapsed and refractory multiple myeloma. DARA interferes with blood compatibility testing by causing panagglutination in the indirect antiglobulin test. In all incompatibilities, immunohematology workup must be done to rule out allo- or autoantibody and to issue compatible unit to the patient. Transfusion support is vital for all these patients with incompatibility and should not be delayed. We encountered one such patient who was undergoing treatment with DARA for refractory multiple myeloma and had incompatibility during crossmatching. Many methods are available to sort out this problem. These include anti-CD38 idiotypes, cord blood, trypsin, papain, dithiothreitol (DTT) treatment, phenotyping, and genotyping. We hereby report resolving the above discrepancy by one of the simplest, cheapest, and feasible methods, i.e., DTT treatment in our blood centers.

Preparation of chitin carbon nanotubes composites and their study on cellular nerve signal transmission and nerve regeneration

Biomedical materials, which are related to human survival and health, have become increasingly noticeable. It is urgent to find an adsorbent that can adsorb bilirubin without affecting protein and coagulation function. Nerve catheter is a method that can promote axonal regeneration and peripheral nerve function recovery. Carbon nanotubes have many excellent functions, such as high adsorption and promotion of nerve cell growth, due to their unique nano-tubular structure and graphite dilute surface, but they are poorly biocompatible. Therefore, combining chitin and carbon nanotubes can increase the bioefficiency of chitin materials and improve the biocompatibility of carbon nanotubes. The construction of a new chitin/carbon nanotube composite will have academic value and application prospects in the field of blood perfusion removal of toxins, neuroscience and tissue engineering. In this study, an alkaline/urea water system was used to dissolve chitin at low temperature, and then mixed with acidified carbon nanotubes to physically build a series of new chitin/carbon nanotube composite materials (hydrogel and nanofibre microspheres). Atomic force microscope (AFM), transmission electron microscope (TEM), scanning electron microscope (SEM), wide-angle X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), laser confocal Raman spectrum, nitrogen adsorption, mechanical property testing, etc. characterise the structure and properties of this series of composite materials, and study the relationship between their structures and properties. To study the application prospects of chitin/carbon nanotube composite hydrogels in neural repair through cell culture experiments, the chitin/carbon nanotube composite nanofibre microspheres through adsorption, plasma perfusion, blood compatibility and cell culture tests were evaluated in the field of hemoperfusion. Nerve regeneration is one of the medical problems, and its related mechanisms have been continuously researched. At present, it has reached the level of cellular molecules. At the same time, research on neural regeneration-related signalling pathways, in-depth understanding of the response mechanism of nerve cells to injury, provide positive theoretical guidance for the treatment of different nerve injuries, and for the development of chitin/carbon nanotubes in nerve conduction and regeneration treatment. The method provides more ideas.

A chitosan modified asymmetric small-diameter vascular graft with anti-thrombotic and anti-bacterial functions for vascular tissue engineering.

Rapid endothelialization and prevention of restenosis are two vital challenges for the preparation of a small-diameter vascular graft (SDVG), while postoperative infection after implantation is often neglected. In the present study, carboxymethyl chitosan (CMC) and chitosan (CS) were chosen as the anti-thrombotic and anti-bacterial components, respectively; and then an asymmetric vascular graft was fabricated by co-electrospinning of poly(ε-caprolactone) (PCL)/CMC and PCL/CS. The mechanical properties of the asymmetric vascular graft were much better than those of the native vessels. In vitro blood compatibility tests indicated that the inner layer of the graft could inhibit thrombosis effectively. The outer layer of the graft had a certain anti-bacterial effect owing to the addition of chitosan. Besides, the inner layer of the graft could greatly promote the growth of endothelial cells. It is believed that the asymmetric SDVG with anti-thrombotic and anti-bacterial functions could contribute to the future clinical implantation of tissue engineered vascular grafts.

Updates on practical ABC blood compatibility testing in cats.

In feline practice, blood groups were considered unimportant until the 1980s. Since then much has been learned. The most important blood group system in cats is the AB (renamed here as ABC) blood group system consisting of blood types A, B and AB (better referred to as C). Type B cats have strong anti-A alloantibodies potentially leading to incompatibility reactions during A-B mismatched transfusions or neonatal isoerythrolysis (NI) in type A and C (AB) kittens born to type B queens. Acute hemolytic transfusion reactions as well as NI have been clinically well documented in cats. Immunological and genetic tests have been established and blood typing and crossmatching test kits have become commercially available. This review updates the current knowledge of these blood types, their genetics, associated incompatibility reactions, and different diagnostic tools for avoiding such reactions in clinical practice.

Optimum DTT Concentration and Treatment Time for CD38 Inactivation on RBCs Analyzed By a Newly-Devised Flow Cytometric Antibody Binding Assay

Background: Anti-CD38 monoclonal antibodies (MoAbs), including daratumumab and isatuximab, are introduced in the treatment of multiple myeloma (MM). However, CD38 is also expressed on red blood cells (RBCs), so that free anti-CD38 MoAbs in patient sera sometimes binds to test RBCs in pretransfusion blood-compatibility tests. Consequently, panreactive agglutination arises in the standard indirect antiglobulin test (IAT) used for antibody screening and cross-matching. Several methods, including pretreatment of RBCs with dithiothreitol (DTT), have been introduced to overcome the interference. However, the optimum concentration and treatment time for these reagents have not been well elucidated (Chapuy et al, Hosokawa et al). One reason is that evaluation for RBC agglutination during the IAT relies on visual judgement. In this study, we quantified CD38 on RBCs before and after DTT treatment using a newly-devised flow cytometric antibody binding assay (FABA; Takeshita et al) by employing the D-value in the Kolmogorov-Smirnov (K-S) test, and compared with the results from IAT and a conventional flow cytometric method using fluorescent labelled anti-CD38 antibody and isotype-matched control antibody. We then assessed the optimum DTT concentration and treatment time for CD38 inactivation on RBCs to enhance MoAb therapy for MM. Methods: RBCs from healthy donors were treated with 0.2-0.0001 mol/L of DTT for 0-30 min at 37°C. The effect of DTT treatment was evaluated using flow cytometetry (FCM, Navious, Beckman Coulter, Tokyo) and IAT. For conventional FCM analysis, untreated or DTT-treated RBCs were incubated with fluorescein isothiocyanate (FITC)-labeled anti-CD38 antibody or anti-IgG1 antibody for 30 min, and then analyzed. For FABA, untreated or DTT treated RBCs were incubated with FITC-labelled anti-CD38 antibody, in the presence or absence of a 100-fold or more excess of unlabeled anti-CD38 antibody and then analyzed by FCM. Dissociation of CD38 positive and control histograms were determined from the mean fluorescence intensity (MFI) and the D-value in the K-S test, which is the maximum vertical displacement between two cumulative frequency distributions for two histograms. Statistical analyses were performed by paired t-test (SPSS, Tokyo), with significance set at p<0.05. The amount of CD38 following DTT treatment was also evaluated by Western blotting. Results: In conventional FCM using FITC-labelled isotype-matched antibody as control, the difference of measured MFIs between CD38 positive and control were considerably volatile in repeated analysis (Fig. A). By contrast, in FABA using an excess concentration of unlabeled anti-CD38 antibody as control, the values were more consistent than those from conventional FCM (Fig. B). The D-value in the K-S test is reliable by numerical modeling in the analysis of the difference between CD38 positive and control histograms. Analysis showed that 0.005 mol/L DTT for 30 min is sufficient to inactivate CD38 on RBCs. These results correlated with those of IAT (Fig. C). Western blotting identified CD38 at DTT concentrations of 0.01-0.001 mol/L, but denaturation of CD38 was observed at 0.2 mol/L of DTT (Fig. D). Conclusions: Our newly-devised flow cytometric antibody binding assay, FABA, facilitates the detection of small numbers of cell surface antigens. The method is also useful as an objective way of evaluating the efficacy of DTT treatment for CD38 on RBCs. Our results show 0.005 mol/L DTT for 30 min is sufficient to inactivate CD38 on RBCs in plasma sampled after treatment with the anti-CD38 MoAbs. Figure Disclosures Takeshita: Chugai Pharmaceutical Co.Ltd.: Research Funding; Pfizer Japan Inc: Research Funding; Astellas Pharma Inc.: Research Funding; Takeda Pharmaceutical Co.Ltd.: Research Funding; Bristol-Myers Squib Co.: Research Funding.

PCL/sulfonated keratin mats for vascular tissue engineering scaffold with potential of catalytic nitric oxide generation.

Heparin-like polymers have a good anticoagulant effect due to some groups similar to heparin. Herein, sulfonated keratin(SK) was prepared by chain transfer radical polymerization of 3-sulfopropyl methacrylate(SPMA) to improve blood coagulation nature of keratin. Poly(ε-caprolactone)(PCL)/SK nanofibrous mats with the ratio of 7 and 3 were then fabricated by electrospinning. In vitro cytotoxicity and blood compatibility tests were performed to assess the biocompatibility. Viability of NIH 3T3 cells on PCL/SK mats was higher than that on the pristine PCL mats, indicating their good cytocompatibility. These sulfonated keratin-containing mats enhanced endothelial cell growth, while inhibited smooth muscle cell proliferation and reduced platelet adhesion in the presence of GSH and GSNO, as a result of NO generation. Furthermore, the biocomposite mats prolonged the activated partial thromboplastin time(APTT) effectively without hemolysis. Taken together, PCL/SK mats are potential for applications in vascular tissue engineering.

Facile Synthesis of Silver Hydroxyapatite (AgHAP) Reinforced Nanocomposites of Poly (styrene)‐Poly (methyl methacrylate) and Study of Their Mechanical and Blood‐Compatible Behavior

AbstractThe present work focused on the synthesis of native silver hydroxyapatite (AgHAP) nanoparticles and their reinforcement into the host matrix of binary polymer blend of polystyrene (PS) and poly (methyl methacrylate) (PMMA). The structural and morphological studies of prepared nanoparticles and AgHAP reinforced PS‐PMMA nanocomposites were performed by various characterization techniques like Fourier transform infrared (FT‐IR) and Raman spectroscopy, X‐ray diffraction, atomic force microscopy (AFM), and Field emission scanning electron microscopy (FESEM). The particle size analysis and zeta potential measurements were used to confirm nanosize of the AgHAP nanoparticles and their surface charges. The mechanical properties of AgHAP/PS/PMMA nanocomposites, such as microhardness and compressive strength, were also determined. The blood compatibility tests were performed to investigate biocompatible nature of the nanocomposites. The antibacterial property of the nanocomposites was also studied against S. aureus and E. coli species and the cytotoxic nature of the nanocomposites was conducted following 3‐(4,5‐Dimethylthiazol‐2‐Yl)‐2,5‐Diphenyltetrazolium Bromide (MTT) assay test.

Manual polybrene (MP), not dithiothreitol (DTT), is the recommended method for blood banking procedure in myeloma patients treated with anti-CD38 monoclonal antibody in Asia

Anti-CD38 monoclonal antibody treatment is known to interfere with the blood compatibility test. Dithiothreitol (DTT) pre-treatment to denature surface CD38 on the reagent erythrocytes is a robust method to mitigate this interference and has been validated internationally (Transfusion, 2016;56;2964-2972). However, the distribution of common alloreactive antibodies differed widely between Asian and Caucasian population. Furthermore, in addition to anti-K, it remains unknown whether DTT pretreatment will decrease the sensitivity in the detection of other allogeneic antibodies common in Asia like anti-Miltenberger (anti-Mia).

Nitrogen and Sulfur Doped Carbon Dots from Amino Acids for Potential Biomedical Applications.

Nitrogen (N-) and sulfur (S-) doped carbon dots (CDs) were synthesized in a single step in a few min,1-4min via microwave technique from five different types of amino acids viz. Arginine (A), Lysine (L), Histidine (H), Cysteine (C), and Methionine (M). These amino acid derived N- and/or S- doped CDs were found to bein spherical shapes with 5-20nm particle sizerange determined by Transition Electron Microscope (TEM) imagesand Dynamic Light Scattering (DLS) measurements. Thermal degradation, functional groups, and surface potential of the CDs were determined by Thermogravimetric Analysis (TGA), FT-IR spectroscopy, and zeta potential measurements, respectively. Although the zeta potential value of Cysteine derived CD (C-CD) wasmeasured as -7.45±1.32mV, the zeta potential values of A-CD, L-CD, H-CD, and M-CD particles were measured as +2.84±0.67, +2.61±1.0, +4.10±1.50 and+2.20±0.60mV, respectively. Amongst the CDs, C- CDs was found to possess the highest quantum yield, 89%. Moreover, the blood compatibility test of CDs, determined with hemolysis and blood clotting tests was shown that CDs at 0.25mg/mL concentration, CDshas less than 5% hemolysis ratio and higher than 50% blood clotting indexes. Furthermore, A-CD was modified with polyethyleneimine (PEI) and wasfound thatthe zeta potential values was increased to +34.41±4.17mV (from +2.84±0.67mV) inducing antimicrobial capability to these materials. Minimum Inhibition Concentration (MIC) of A-CD dots was found as 2.5mg/mL whereas the PEI modified A-CDs, A-CD-PEI was found as 1mg/mL against Escherichia coli ATCC 8739 (gram -) and Staphylococcus aureus ATCC 6538 (gram +) bacteria strains signifying the tunability of CDs.

2019 Canadian Surgery Forum Abstracts.

# 01. The future of general surgery training: a Canadian resident nationwide Delphi consensus statement {#article-title-2} Various pedagogical models have been introduced in an attempt to improve and restructure surgical training, but significant obstacles remain. Before implementing national

Cholesterol removal from human plasma with biologically modified cryogels

In this study, low molecular weight heparin immobilized P(HEMA) cryogels were fabricated for the removal of LDL-C in hypercholesterolemic human plasma. After characterization studies for P(HEMA) cryogels, effects of the parameters including medium pH, CNBr concentration, heparin concentration and contact time on heparin immobilization were investigated. Blood compatibility and cell adhesion tests were also performed, and platelet and leucocyte loss for P(HEMA)-Hp cryogels were found to be 2.95% and 4.91%, respectively. Maximum adsorption capacity for LDL-C from hypercholesterolemic human plasma was found to be 26.7 mg/g for P(HEMA)-Hp cryogel while it was only 1.67 mg/g for bare P(HEMA) cryogel. The P(HEMA)-Hp cryogels exhibit high desorption ratios up to 96% after 10 adsorption-desorption cycles with no significant decrease in the adsorption capacity. The findings indicated that these reusable P(HEMA)-based cryogels proposed good alternative adsorbents for removal of LDL-C.

Controversies Regarding Compatibility in Xenotransfusion With Blood From Dog to Cat (Review)

As it is well known, any incompatible blood transfusion can generate adverse reactions in feline patients, because cats naturally have plasmatic alloantibodies. Even so, recent scientific studies have shown that transfusions with heterologous blood (canine) to cats, were indeed followed by mild hemolysis states, in cases of severely anemic patients. A repeated transfusion however will cause anaphylactic shock with fatal outcome. Based on the data we have studied, we consider xenotransfusion, even though still controversial, to be considered as an emergency therapeutic procedure when superior, homologous blood cannot be acquired for felines. Through this review we hope to offer clinicians the necessary information to consider xenotransfusion as an alternative in emergency therapy, when this is rigorously sustained by blood compatibility tests and when all other options have been excluded only.

PS1594 EXPERIENCE WITH THE NEUTRALIZING AGENT DARAEX® IN BLOOD COMPATIBILITY TESTS IN PATIENTS TREATED WITH DARATUMUMAB

Background:Daratumumab is a human monoclonal antibody used for the treatment of multiple myeloma, which binds to CD38, a protein that is expressed on red blood cells (RBCs). Therefore, the plasma of these patients reacts with the RBCs producing a panreactivity and interfering in the transfusion compatibility testing. Panagglutination may persist for up to 6 months after the last infusion of daratumumab. An anti‐CD38 antibody for treatment of multiple myeloma shows a strong interference in the indirect antiglobulin test (IAT) where most of the reactions turn to unspecifically (wrong) positive. The time consuming standard technique using Dithiothreitol (DTT) counteracts the interference but has major drawbacks like destruction of Kel antigens or hemolysis. The DaraEx® compound inhibits the agglutination effect of anti‐CD38 in IAT without side effects. DaraEx® is a neutralizing agent for the inhibition of the agglutination effect of the anti‐CD38 antibody daratumumab in IAT.Aims:To validate the procedure to resolve the interference of daratumumab in transfusion compatibility testing using red cells treated with DaraEx® for the inhibition of the agglutination effect of the anti‐CD38 antibody daratumumab in IAT. Daratumumab can interfere with crossmatching and antibody screening in the IAT, which will allow us to identify a clinically significant antibody that has been initially masked by the presence of daratumumab.Methods:The study has been conducted in 25 plasma samples of patients diagnosed with multiple myeloma who have been treated with daratumumab. Irregular antibody screening tests and CrossMatching were performed on all of them, being positive in all cases. We performed the technique to eliminate reactivity by treating the red cells used in compatibility tests with DaraEx®, which neutralizes CD38 on the surface of the erythrocyte, thereby preventing Daratumumab from binding and inducing agglutination. The material used was DaraEx®, 0.9% NaCl LISS/Coombs ID‐Cards and Test cell reagents for the ID‐System; We performed the method in Biovue Column Agglutination Technology and gel card systems.Results:After performing the technique, we were able to eliminate panreactivity in both Irregular antibody screening tests and CrossMatching.Summary/Conclusion:Daratumumab causes panreactivity in vitro by binding to CD38 on reagent RBCs. It is necessary to do a baseline antibody screen (type and screen) before starting the treatment with daratumumab. Treating reagent RBCs with DaraEx® is a useful easy and quick method to mitigate the interference created by antiCD38 mAbs in pretransfusion testing. DaraEx is a quick and simple procedure; it doesn’t affect other antigens or alloantibody reactions. It doesn’t have side effects like destruction of blood group antigens or hemolysis as described for the standard DTT treatment. Therefore, we consider it a very useful technique to resolve interferences produced by daratumumb with blood compatibility testing. We believe that it is essential to have a validated technique to resolve these discrepancies. If an emergency transfusion is required, noncrossmatched, ABO/RhD‐compatible RBCs can be given, per local blood bank practices.

Chemical and biological behaviours of hydrogels based on oxidized carboxymethylcellulose coupled to chitosan

Carboxymethylcellulose (CMC) was subjected to partial oxidation reaction by 2,2,6,6-tetramethylpiperidine-1-oxyl in the presence of sodium hypochlorite (NaOCl) and sodium bromide (NaBr). Hydroxylamine and acid–base assay methods were used to quantify the aldehyde and carboxyl groups, respectively. Chitosan (CS) was then coupled to CMC or oxidized CMC (OCMC). The carboxyl groups carried by CMC and the free amines by CS were estimated by potentiometry and conductimetry. Characterization and identification of the obtained materials were made by Fourier transform infrared spectroscopy, Ultraviolet–visible spectroscopy and X-ray fluorescence. The blood compatibility test shows that the haemolysis percentages of films are less than 5%, which indicates their good blood compatibility and their non-haemotoxicity. The anti-inflammatory activity reveals that the materials possess an ability to inhibit the denaturation of proteins. The mucoadhesion tests exhibit a marked increase in adhesion times of CMC/CS and OCMC/CS hydrogels on the intestinal mucosa. Besides, swelling behaviour and biodegradability were established.