Blood Repellency Research Articles

Combining Chitosan, Stearic Acid, and (Cu-, Zn-) MOFs to Prepare Robust Superhydrophobic Coatings with Biomedical Multifunctionalities.

There is an urgent need to develop a series of multifunctional materials with good biocompatibility, high mechanical strength, hemostatic properties, antiadhesion, and anti-infection for applications in wound care. However, successfully developing multifunctional materials is challenging. In this study, two superhydrophobic composite coatings with good biocompatibility, high mechanical strength, strong antifouling and blood repellency, fast hemostasis, and good antibacterial activity areprepared on cotton fabric surface by simple, green, and low-cost one-step dip-coating technology. The results discussed in the manuscript reveals that the two superhydrophobic composite coatings can maintain good mechanical stability, strong water repellency, and durability under various types of mechanical damage, high-temperature treatment, and long-term strong light irradiation. The coatings also exhibit good repellency to various solid pollutants, highly viscous liquid pollutants, and blood. In vitro and in vivo hemostatic experiments show that both composite coatings havegood hemostatic and anticlot adhesion properties. More importantly, this superhydrophobic coating prevents bacterial adhesion and growth and released Cu2+ and Zn2+ ions and chitosan to achieve bactericidal properties, thereby protecting injured skin from bacterial infection. The two superhydrophobic coatings enhance the antifouling, antiadhesion, hemostatic, and antibacterial functions of blood-repellent dressings and therefore have broad application prospects in medical and textile fields.

Self-cleaning, superhydrophobic, and antibacterial cotton fabrics with chitosan-based composite coatings

The development of cotton fabrics with special properties such as superhydrophobicity, self-cleaning, oil/water separation, anti-bacterial activity and blood repellency without compromising its intrinsic properties such as flexibility, breathability, comfort, and biodegradability is quite challenging task. In this study, a simple and environmentally friendly approach was used to fabricate superhydrophobic cotton fabric by introducing chitosan-based composite coatings over cotton fabric. The surface properties of the cotton samples were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The prepared cotton fabrics showed excellent superhydrophobicity with a water contact angle of 154.4° and also possess excellent antibacterial activity against Gram positive and negative bacteria with inhibition zone of 16 mm and 22 mm in disk diffusion method and shake flask method results revealed that the chitosan-PAni-ZnO-STA coated cotton effectively inhibits the bacterial growth. Furthermore, the self-cleaning, blood repellency and oil-water separation performance of cotton fabric were also performed to examine the feasibility of as-modified cotton in both environmental and clinical applications.

Increased body fluid repellency and electrochemical corrosion resistance of intravascular stent materials by ICP-CVD-based DLC thin-film deposition

Intravascular stents face adhesion- and corrosion-based challenges causing In-stent Restenosis (ISR). This study analyzes the influences of thin-film Diamond-Like-Carbon (DLC) deposition on body fluid repellency and corrosion behavior in Simulated Body Fluid (SBF) at 37 °C for intravascular stent materials. The stent specimens of 316 L and 316 LVM stainless steel, Ti-Alloy, and CoCr-Alloy were coated with DLC thin-films by Inductively Coupled Plasma Chemical Vapor Deposition (ICP-CVD). The repellencies of bare and DLC-coated specimens to body fluids, including the blood, plasma, glycerol, and distilled water (DIW) were analyzed by their Contact Angles (CA). Electrochemical impedance spectroscopy (EIS) and corrosion analysis in simulated body fluid were conducted using a potentiostat system. Bare specimens exhibited hydrophilic behavior with 51° CA for distilled water and lower body fluid repellencies with 69°, 64°, and 57° CAs for total blood, blood plasma, and glycerol, respectively. DLC coating improved blood repellency to 88° CA and hydrophobic feature to 81° CA. The electrochemical corrosion analysis exhibited that ICP-CVD based DLC thin-film deposition increased the electrochemical polarization resistance of BMS specimens from 22.02 kΩ.cm2 to 386.6 kΩ.cm2 for 316 L SS, 408.8 kΩ.cm2 for 316 LVM SS, 1703.0 kΩ.cm2 for CoCr-Alloy, and 1748 kΩ.cm2 for Ti-Alloy. The obtained values reduced the corrosion rate from 447.1 μm/year to 0.241 μm/year and the mass loss rate from 357.1 mg/cm2year to 0.165 mg/cm2year. This study concludes that DLC thin-film structures can lower the risk of ISR by adhesion and corrosion inhibition in BMS specimens, and they have a potential application in fluid-repellent and anti-corrosive drug-free stents.

Superhydrophobic blood-repellent tubes for clinical cardiac surgery

Superhydrophobic coatings are gaining importance not only in military technology, industrial engineering, power systems and transportation, but also in food science and biomedicine, where they have enormous potential for real-time applications. Many research institutes have recently been working on the development of superhydrophobic blood-repellent tubes to replace clinical heparin-coated tubes during ECMO therapy, but biological toxicity and high blood adhesion have significantly hampered their practical applications. In this study, we created a cardiopulmonary bypass tube with good superhydrophobicity and blood repellency. In terms of biotoxicity, coagulation time, protein and platelet adsorption, the results show that the superhydrophobic-treated tube clotted in 36 min, compared to 21 min for a clinical Bioline heparin-coated tube and 14 min for bare PVC tube. When compared to the bare PVC tube, the clotting time of the superhydrophobic-treated tube was increased by 157% due to the Cassie-Baxter wetting state of the resulting superhydrophobic blood-repellent coating. Meanwhile, the protein and platelet adsorption on the superhydrophobic-treated tube were decreased by 32% and 74%, respectively. It should be noted that we were the first to explain the superhydrophobic anti-platelet adsorption mechanism from the perspective of inhibiting thromboxane-A2 secretion during blood coagulation. Clarification of platelet activation process and activating substances is vital for understanding the anticoagulant properties of superhydrophobic coatings. On the other hand, non-inflammatory response of the organism was confirmed in the vivo experiments and the cell viability after a 48-hour cytotoxicity assay was about 101%, indicating that the superhydrophobic-treated tubes are non-toxic.

Asymmetric composite wound nanodressing with superhydrophilic/superhydrophobic alternate pattern for reducing blood loss and adhesion

Wound dressings are of great importance in trauma medicine. However, such dressings are poor in hemostatic effect, and they easily adhere to the wound skin, leading to their unsatisfactory effects for clinical application. Herein, we developed a new concept of creating an asymmetric composite wound nanodressing (ACWN) with unique structure consisting of superhydrophilic/superhydrophobic alternate inner layer and superhydrophobic outer layer. Compared to traditional hemostatic materials, our fabricated material consisted of integration of alternate micropattern wettability of the inner layer and the asymmetric wettability of the inner/outer layers into simple gauze. This ACWN was verified to overcome the challenge of reducing blood loss and simultaneously reducing adhesion based on the results of rat experiments both in in vivo and in vitro. Importantly, the resulting ACWN exhibited efficient blood absorption and clotting abilities on the zone of superhydrophilic inner layer. Moreover, the zone of superhydrophobic inner layer with blood repellency could avoid pain and secondary injuries caused by forced removal of dressings, and its outer layer could further prevent blood extravasation and reduce the risk of infection. Undoubtedly, this effective strategy provides new insight into the practical application of hemostatic materials.

Preparation of superhydrophobic flexible tubes with water and blood repellency based on template method

Superhydrophobic surfaces have been widely used in biology, medicine, aerospace and other fields due to their special surface wettability. The surface wettability of materials mainly depends on the surface chemical composition and surface morphology. Therefore, the wettability of materials can be effectively controlled by changing the surface chemical composition and surface morphology. In this paper, the hydrophobic templates with different wettability were obtained by controlling the laser etching distance of 6061 aluminium alloy tube surface. The superhydrophobic flexible tubes were further fabricated using prepared 6061 aluminum alloy tubes as the template and polydimethylsiloxane (PDMS) for replica. The contact angles of water and blood could reach 162.8°and 152.1° respectively. By using scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR), it could be seen that there were micron-sized structures and hydrophobic groups on the surface. The free energy on the surface of superhydrophobic PDMS was 70.7% lower than that on smooth PDMS. In addition, the superhydrophobic flexible tube had excellent durability and abrasion resistance, and the prepared surface was also blood repellency. Blood droplets easily passed through the inclined flexible tube without contaminating the tube. And the superhydrophobic flexible tubes could be used in various fields requiring productivity extensively, such as medical catheters.

Self-Cleaning Properties of TiN/CrN Nanoscale Multi-layer Deposited on Surgical 420C Stainless Steel

The present paper focuses on the investigation of self-cleaning properties based on studding of water repellency and blood repellency for TiN- and CrN single-layer and TiN/CrN nanoscale multi-layer coatings deposited via Cathodic Arc Evaporation (CAE) method on medical grade 420C stainless steel substrate. X-ray diffraction (XRD) method and Field Emission Scanning Electron Microscope (FESEM) was used to characterize microstructure. Surface roughness parameters were measured by using Taylor-Habsson method. Blood contact angle and water contact angle measurements test were applied to characterize the self-cleaning properties of the specimens. The analysis of sample data shows that coated specimens have more water contact angle values in comparison to bare steel. Among the coated samples, CrN single-layer has the highest water contact angle (80°) due to its lower surface roughness (Ra=0.189µm) among the other samples. Moreover, the findings of the paper prove that samples had inverse behavior against blood and water in the contact angle measurement test. Bare steel has higher blood contact angle (76.1°) and more blood repellency than the coated specimens. It seems that the different behavior of samples against water and blood in contact angle tests is due to the nature of two fluids. TiN/CrN multi-layer coating results had minor differences in water and blood contact angle tests (67.3° and 62.2° respectively).

Development of tri-layer breathable fluid barrier nonwoven fabrics for surgical gown applications

In this study, tri-layer fabrics for surgical gown applications were developed using polypropylene spunbond, polypropylene melt-blown and polyester/rayon spunlace (hydro-entangled) nonwoven layers with the aid of a fusing machine and polypropylene powder as the bonding agent. Weight, thickness, bending rigidity, grab tensile properties, bursting strength, air permeability, water vapour transmission rate, hydrostatic pressure, water resistance (impact penetration test), and synthetic blood repellency of the fabrics (unfinished and finished with water repellent polymethylhydrosiloxanes solution) were measured and the data was statistically analyzed. The results showed that the finished fabric composed of the spunbond outer layer, melt-blown middle layer, and spunlace inner layer, meets the blood repellency requirements of level 4 protection according to the barrier protection classification of Association for the Advancement of Medical Instrumentation (AAMI). The other samples, i.e. untreated type of abovementioned sample and treated and untreated tri-layer of spunbond, melt-blown, spunbond samples offer level 2 protection according to AAMI classification.

Blood‐Repellent Surfaces: Superhydrophobic Blood‐Repellent Surfaces (Adv. Mater. 24/2018)

Blood-repellent superhydrophobic surfaces aim toward reducing the thrombogenicity of the surfaces of blood-contacting devices and implants. In article number 1705104, Ville Jokinen, Esko Kankuri, Robin H. A. Ras, and co-workers highlight several recent examples of such surfaces, where, for example, blood droplets in the superhydrophobic Cassie state roll off a micro and nanostructured PDMS–titania hybrid surface easily, without leaving a stain. Several mechanisms that lead to blood repellency are proposed, focusing mainly on platelet antiadhesion. Image credits: Sasha Hoshian (preparing material samples and set up), and Valeria Azovskaya (photography and graphic design).

Superhydrophobic Blood-Repellent Surfaces.

Superhydrophobic surfaces repel water and, in some cases, other liquids as well. The repellency is caused by topographical features at the nano-/microscale and low surface energy. Blood is a challenging liquid to repel due to its high propensity for activation of intrinsic hemostatic mechanisms, induction of coagulation, and platelet activation upon contact with foreign surfaces. Imbalanced activation of coagulation drives thrombogenesis or formation of blood clots that can occlude the blood flow either on-site or further downstream as emboli, exposing tissues to ischemia and infarction. Blood-repellent superhydrophobic surfaces aim toward reducing the thrombogenicity of surfaces of blood-contacting devices and implants. Several mechanisms that lead to blood repellency are proposed, focusing mainly on platelet antiadhesion. Structured surfaces can: (i) reduce the effective area exposed to platelets, (ii) reduce the adhesion area available to individual platelets, (iii) cause hydrodynamic effects that reduce platelet adhesion, and (iv) reduce or alter protein adsorption in a way that is not conducive to thrombus formation. These mechanisms benefit from the superhydrophobic Cassie state, in which a thin layer of air is trapped between the solid surface and the liquid. The connections between water- and blood repellency are discussed and several recent examples of blood-repellent superhydrophobic surfaces are highlighted.

Facile Fabrication and Characterization of a PDMS-Derived Candle Soot Coated Stable Biocompatible Superhydrophobic and Superhemophobic Surface

We report a simple, inexpensive, rapid, and one-step method for the fabrication of a stable and biocompatible superhydrophobic and superhemophobic surface. The proposed surface comprises candle soot particles embedded in a mixture of PDMS+n-hexane serving as the base material. The mechanism responsible for the superhydrophobic behavior of the surface is explained, and the surface is characterized based on its morphology and elemental composition, wetting properties, mechanical and chemical stability, and biocompatibility. The effect of %n-hexane in PDMS, the thickness of the PDMS+n-hexane layer (in terms of spin coating speed) and sooting time on the wetting property of the surface is studied. The proposed surface exhibits nanoscale surface asperities (average roughness of 187 nm), chemical compositions of soot particles, very high water and blood repellency along with excellent mechanical and chemical stability and excellent biocompatibility against blood sample and biological cells. The water contact angle and roll-off angle is measured as 160° ± 1° and 2°, respectively, and the blood contact angle is found to be 154° ± 1°, which indicates that the surface is superhydrophobic and superhemophobic. The proposed superhydrophobic and superhemophobic surface offers significantly improved (>40%) cell viability as compared to glass and PDMS surfaces.

Ion-Specific Modulation of Interfacial Interaction Potentials between Solid Substrates and Cell-Sized Particles Mediated via Zwitterionic, Super-Hydrophilic Poly(sulfobetaine) Brushes.

Zwitterionic polymer brushes draw increasing attention not only because of their superhydrophilic, self-cleaning capability but also due to their excellent antifouling capacity. We investigated the ion-specific modulation of the interfacial interaction potential via densely packed, uniform poly(sulfobetaine) brushes. The vertical Brownian motion of a cell-sized latex particle was monitored by microinterferometry, yielding the effective interfacial interaction potentials V(Δh) and the autocorrelation function of height fluctuation. The potential curvature V″(Δh) exhibited a monotonic increase according to the increase in monovalent salt concentrations, implying the sharpening of the potential confinement. An opposite tendency was observed in CaCl2 solutions, suggesting that the ion specific modulation cannot be explained by the classical Hofmeister series. When the particle fluctuation was monitored in the presence of free sulfobetaine molecules, the increase in [sulfobetaine] resulted in a distinct increase in hydrodynamic friction. This was never observed in all the other salt solutions, suggesting the interference of zwitterionic pairing of sulfobetaine side chains by the intercalation of sulfobetaine molecules into the brush layer. Furthermore, poly(sulfobetaine) brushes exhibited a very low V″(Δh) and hydrodynamic friction to human erythrocytes, which seems to explain the excellent blood repellency of zwitterionic polymer materials.

Studies on the properties of nonwoven surgical gowns

Polypropylene spunbond, spunbond/meltblown/spunbond, and spunlace fabrics of 35 and 50 g/m2 weight are tested for barrier properties against microorganisms and liquid or body fluids to estimate their suitability for surgical gowns. The fabrics are also treated with different levels of antibacterial and fluorochemical finishes in a single bath using pad-dry-cure method. Liquid barrier properties of samples are analyzed by water impact penetration, hydrostatic pressure test, and blood repellency test. Parallel streak method is used to measure the antibacterial activity on the fabric samples with Staphylococcus aureus. The fabric samples are also analyzed for air permeability and stiffness. It is observed that spunbond/meltblown/spunbond fabric of 35 and 50 g/m2 weight offer sufficient liquid barrier properties for level 2 protection as per the Association for the Advancement of Medical Instrumentation barrier protection classification. Spunlace and spunbond fabrics of 35 and 50 g/m2 weight offer only level 1 protection. Spunbond/meltblown/spunbond fabrics are poorest in terms of comfort, because of their higher stiffness and lower air permeability values; spunlace fabric offers the highest air permeability and lowest stiffness force. Spunbond/meltblown/spunbond fabric samples with 4% and 7% fluorochemical finish and 1.5% antibacterial finish can provide level 4 protection. Spunbond fabrics require 4% and spunbond/meltblown/spunbond fabrics require 1% fluorochemical finish to achieve level 2 protection.

Surface Modification of Stainless Steel for Surgical Tool by EB-Polishing

A new surface finishing method by large-area electron beam irradiation (EB-polishing) for stainless steels for orthopedic surgical tool was proposed in our previous paper, and it was shown that high-efficient surface finishing was possible by the EB-polishing. In this report, the surface structure of EB-polished stainless steel is analyzed by TEM and EDX. Also, surface modification effects such as resistance to corrosion and blood repellency are evaluated. Then, the applicability of the EB-polishing as a new surface modification method of stainless steel for orthopedic surgical tool is discussed.

E27 Addition of Surface Functions to Orthopedic Surgical Tools and Jigs by Large-area Electron Beam Irradiation(Electrical machining)

In the large-area electron beam (LAEB) irradiation method used in this study, electron beam with high energy density can be irradiated without concentrating the beam, so that LAEB of 60 mm in diameter can melt or evaporate metal surface instantly. In this study, the surface characteristics of LAEB irradiated stainless steels for orthopedic surgical tools and jigs, such as resistance to bacteria adhesion, blood repellency and corrosion resistance were investigated. Experimental results clarified that these surface characteristics could be improved by LAEB irradiation. Therefore, LAEB irradiation method enables the high-efficient surface treatment of surgical tools and jigs.

Surface finishing of stainless steels for orthopedic surgical tools by large-area electron beam irradiation

Surgical tools and jigs are initially machined by multi-axis milling. Then surface finishing is carried out mainly by hand lapping. As these tools undergo repeated use, the removal of burrs, scratches and rust from the surfaces is also performed manually after each operation. These finishing processes are time-consuming and costly. In this study, a new finishing method by large-area electron beam irradiation is proposed. Electron beam (EB) with high energy density can be obtained without focusing the beam, and large-area EB can be used for instantly melting or evaporating the metal surface. Stainless steel for surgical tools and jigs was treated by the large-area EB irradiation method. The experimental results show that highly efficient surface smoothing of stainless steels by large-area EB irradiation may be achieved. In addition, the resistance to corrosion and blood repellency can be improved simultaneously with surface smoothing.

Antimicrobial and Blood Repellent Finishes for Cotton and Nonwoven Fabrics Based on Chitosan and Fluoropolymers

In order to impart barrier properties against microorganisms and blood to 100% cotton fabrics and 55/45% woodpulp/polyester spunlaced nonwoven fabrics, samples are treated with chitosan and fluoropolymers using the pad-dry-cure and pad-cure meth ods, respectively. Antimicrobial activity of the samples is analyzed quantitatively by measuring the number of colonies of Staphylococcus aureus. Blood repellency is as sessed with an impact penetration test using synthetic blood. Laundering durability of the finishes is measured, and scanning electron microscopy is used to evaluate changes in the fabric surfaces. To investigate the effect of finishing on the hand and air per meability of fabrics, the mechanical properties of the samples are measured by the KES-FB system. Samples treated only with chitosan show a high reduction rate in the number of colonies. Dual finished specimens treated with 1.1 % chitosan concentration also maintain over 90% reductions in the number of colonies. The blood repellency of dual finished nonwoven fabrics is superior to that of dual finished cotton. Dual finished cotton fabrics exhibited durable antimicrobial activity with repeated laundering. As regards mechanical properties, bending rigidity and shear rigidity increase when cotton and nonwoven fabrics are treated only with chitosan, but these properties decrease after the fluoropolymer treatment. Air permeability of the specimens decreases slightly after the dual finish.

Effect of a Dual Function Finish Containing an Antibiotic and a Fluorochemical on the Antimicrobial Properties and Blood Repellency of Surgical Gown Materials

In order to provide 100% cotton fabric and 55/45% woodpulp/polyester spunlaced nonwoven fabric with barriers against microorganisms and blood, samples are treated with gentamicin, a broad-spectrum antibiotic, and a fluorochemical compound using the pad-cure method. The antimicrobial activity of the samples is analyzed quantitatively by measuring the number of colonies of Klebsiella pneumonia, and qualitatively using the parallel streak method with Staphylococcus aureus. Blood repellency is assessed with spray and impact penetration tests using both synthetic and human blood. Samples treated with both the antibiotic and the fluorochemical (dual finish) show a high reduction rate in the number of colonies grown and clear zones of inhibition, which is the same as the antimicrobial properties of the samples treated with antimicrobial finishing agent only. The blood repellency of dual finished nonwoven fabrics is superior to that of dual finished cotton. The optimum concentration of the fluorochemical for synthetic blood repellency is 5% owf.