Correction: Blood compatibility of a new zwitterionic bare metal stent with hyperbranched polymer brushes

Correction for ‘Blood compatibility of a new zwitterionic bare metal stent with hyperbranched polymer brushes’ by Xiaobo Wang et al., J. Mater. Chem. B, 2013, 1, 5036–5044, DOI: 10.1039/C3TB20855A.

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.

Control of Blood Coagulation by Hemocompatible Material Surfaces—A Review

Hemocompatibility of biomaterials in contact with the blood of patients is a prerequisite for the short- and long-term applications of medical devices such as cardiovascular stents, artificial heart valves, ventricular assist devices, catheters, blood linings and extracorporeal devices such as artificial kidneys (hemodialysis), extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass. Although lower blood compatibility of materials and devices can be handled with systemic anticoagulation, its side effects, such as an increased bleeding risk, make materials that have a better hemocompatibility highly desirable, particularly in long-term applications. This review provides a short overview on the basic mechanisms of blood coagulation including plasmatic coagulation and blood platelets, as well as the activation of the complement system. Furthermore, a survey on concepts for tailoring the blood response of biomaterials to improve the hemocompatibility of medical devices is given which covers different approaches that either inhibit interaction of material surfaces with blood components completely or control the response of the coagulation system, blood platelets and leukocytes.

Applying Different Chemical Methods to Develop an Efficient Acellular Rat Uterine Tissue Matrix

Purpose: Decellularized uterine scaffold, as a new achievement in tissue engineering, permits recellularization and regeneration of uterine tissues and supports pregnancy in a fashion comparable to the intact uterus. The main purpose of this study was using of different chemical methods to introduce an optimized protocol for decellularization of rat uterus.Method: We decellularized rat uteruses by four different protocols using sodium dodecyl sulfate (SDS) and triton-X100 with different doses and time incubations.We characterized the scaffolds through histopathological staining, DNA quantification, MTT assay, Blood compatibility assay, Field Emission Scanning Electron Microscopy (FESEM), and biomechanical studies.Results: Histology assessment showed that only in protocol 4, cell residues were completely removed. Masson’s trichrome staining demonstrates that in protocol P3 collagen bundles were decreased; however, no damage in the collagen bundles was observed by other protocols. Cell viabilities indirect MTT assays of all protocols were significantly higher than the native samples. The RBC hemolysis percent in the presence of prepared scaffolds from all 4 protocols was less than 2%. The mechanical properties of none of the protocols were significantly different from the native sample. Conclusion: Protocol 4 which used freeze-thawing before using detergent, was introduced as the optimized protocol due to complete removal of cell residue, preservation of the three-dimensional structure, complete removal of detergents, and preservation of the mechanical property of the scaffolds.

PLGA Coatings and PLGA Drug-Loading Coatings for Cardiac Stent Samples: Degradation Characteristics and Blood Compatibility

PLGA (Poly lactic-co-glycolic acid) and PLGA drug-loading coatings were prepared on 316 L stainless steel by electrostatic spray deposition (ESD). The surface morphology, three-dimensional morphology, and crystal structures of the coatings were observed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Thermal properties, molecular weight, and coating composition were studied by differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and NMR. The degradation behaviors of the coatings were studied by mass changes, relative molecular mass and distributions, polymer compositions, thermal properties, and surface morphologies. The blood compatibilities of the coatings were investigated by platelet adhesion testing and dynamic coagulation times. SEM results indicated the drug-loading coating with 33% RAPA had the smoothest and most compact morphology. Addition of RAPA decreased the Tg of the PLGA coating, accompanied by partial crystallization that slowed the degradation rate of the drug-loaded coating. Microscopically, the morphology of the PLGA drug-loaded coating was coarser than the PLGA coating. The average surface roughness values of line and surface scannings were 16.232 nm and 39.538 nm, respectively. The surface of the drug-loading coating was micro uneven, and the macro smooth and micro multiphase separation structure helped improve its blood compatibility.

Blood Compatibility of Amphiphilic Phosphorous Dendrons—Prospective Drug Nanocarriers

Dendrons are branched synthetic polymers suitable for preparation of nanosized drug delivery systems. Their interactions with biological systems are mainly predetermined by their chemical structure, terminal groups, surface charge, and the number of branched layers (generation). Any new compound intended to be used, alone or in combination, for medical purposes in humans must be compatible with blood. This study combined results from in vitro experiments on human blood and from laboratory experiments designed to assess the effect of amphiphilic phosphorous dendrons on blood components and model membranes, and to examine the presence and nature of interactions leading to a potential safety concern. The changes in hematological and coagulation parameters upon the addition of dendrons in the concentration range of 2–10 µM were monitored. We found that only the combination of higher concentration and higher generation of the dendron affected the selected clinically relevant parameters: it significantly decreased platelet count and plateletcrit, shortened thrombin time, and increased activated partial thromboplastin time. At the same time, occasional small-sized platelet clumps in blood films under the light microscope were observed. We further investigated aggregation propensity of the positively charged dendrons in model conditions using zwitterionic and negatively charged liposomes. The observed changes in size and zeta potential indicated the electrostatic nature of the interaction. Overall, we proved that the low-generation amphiphilic phosphorous dendrons were compatible with blood within the studied concentration range. However, interactions between high-generation dendrons at bulk concentrations above 10 µM and platelets and/or clotting factors cannot be excluded.

Graphene Oxide-Lignin/Silk Fibroin/ZnO Nanobiocomposite: A Novel Bioactive Scaffold With Antibacterial Activity

In this study, a novel nanobiocomposite was synthesized using graphene oxide, lignin, silk fibroin and ZnO and used in biological fields. To synthesize this structure, after preparing graphene oxide by the Hummer method, lignin, silk fibroin, and ZnO nanoparticles (NPs) were added to it, respectively. Also, ZnO NPs with a particle size of about 18 nm to 33 nm was synthesized via Camellia sinensis extract by green methodology. The synthesized structure was examined as anti-biofilm agent and it was observed that the Graphene oxide-lignin/silk fibroin/ZnO nanobiocomposite has a significant ability to prevent the formation of P. aeruginosa biofilm. In addition, due to the importance of the possibility of using this structure in biological environments, its toxicity and blood compatibility were also evaluated. According to the obtained results from MTT assay, the viability percentages of Hu02 cells treated with Graphene oxide-lignin/silk fibroin/ZnO nanobiocomposite after 24, 48, and 72 h of incubation were 89.96%, 89.32%, and 91.28%. On the other hand, the hemolysis percentage of the synthesized structure after 24 h and 72 h of extraction was 9.5% and 11.76% respectively. As a result, the synthesized structure is hemocompatible and had no toxic effects on Hu02 cells.

Investigation of Minerals Substituted Hydroxyapatite Based Nanocomposite Coated Titanium Implant for Bone Tissue Engineering Applications

In this paper, the collagen (Col)@minerals (Sr, Mg, Ce) substituted hydroxyapatite (MHA1)-halloysite nanotubes - single-walled carbon nanotubes (SWCNT) (Col@MHA1-HNT-SWCNT) nanocomposite was coated on the titanium (Ti) implant was investigated using the electrophoretic deposition (EPD) method. The phase and microstructure analysis of the coated samples were characterized using XRD, and SEM-EDAX, respectively. The Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) strains were tested for antimicrobial activity. The zone of inhibition shows that the Col@MHA1-HNT-SWCNT nanocomposite coating was effective at inhibiting pathogens. The analysis of blood compatibility revealed that the hemolytic ratio was less than 5%, confirming that the nanocomposite were naturally hemocompatible. Furthermore, the cell viability assay using osteoblast-like cells showed excellent cell proliferation and attachments on prepared samples. According to the findings of this research, the Col@MHA1-HNT-SWCNT nanocomposite coating supports bioactivity through fast osteo-compatibility and has greater bacterial resistance, making it necessary for the required biomedical applications.

Blood Compatibility of Widely used Central Venous Catheters; an Experimental Study

Background: An inserted central venous catheter (CVC) is considered foreign material by the inert host defence systems and induce inflammation and thrombus formation. The objective of this study was to evaluate blood compatibility of six commonly used CVCs.Methods: Three coated and three uncoated CVC materials were tested in a modified Chandler loop model. Each catheter material circulated in blood from ten different healthy volunteers for 1 hour. Blood cell counts and measurements of the inert host defence systems were performed on blood samples from the loop.Results: All the tested catheters demonstrated impact on blood cells, contact coagulation, the complement system, or inflammatory markers, although the impact varied significantly.Conclusions: Of the catheters we evaluated, the most unfavourable blood compatibility profile was found for the polyurethane CVC coated with chlorohexidine and silver sulfadiazine. The greatest variation in blood compatibility between test runs was noted for the silicone dialysis catheter. Poor blood compatibility should be taken seriously but given the experimental design of the current study the clinical significance remains to be evaluated.