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International Journal of Molecular... May 2023Thermal insulating composites are indispensable in electronic applications; however, their poor thermal conductivity and flexibility have become bottlenecks for...
Thermal insulating composites are indispensable in electronic applications; however, their poor thermal conductivity and flexibility have become bottlenecks for improving device operations. Hexagonal boron nitride (BN) has excellent thermal conductivity and insulating properties and is an ideal filler for preparing thermally insulating polymer composites. In this study, we report a method to fabricate BN/polyurethane (PU) composites using an improved nonsolvent-induced phase separation method with binary solvents to improve the thermal performance and flexibility of PU. The stress and strain of BN60/PU are 7.52 ± 0.87 MPa and 707.34 ± 38.34%, respectively. As prepared, BN60/PU composites with unordered BN exhibited high thermal conductivity and a volume resistivity of 0.653 W/(m·K) and 23.9 × 10 Ω·cm, which are 218.71 and 39.77% higher than that of pure PU, respectively. Moreover, these composite films demonstrated a thermal diffusion ability and maintained good integrity after 1000 bending cycles, demonstrating good mechanical and thermal reliability for practical use. Our findings provide a practical route for the production of flexible materials for efficient thermal management.
Topics: Polyurethanes; Reproducibility of Results; Thermal Conductivity; Electronics
PubMed: 37175928
DOI: 10.3390/ijms24098221 -
Journal of Materials Chemistry. B Sep 2020Polydimethylsiloxane (PDMS) is commonly used in medical devices because it is non-toxic and stable against oxidative stress. Relatively high blood platelet adhesion and...
Polydimethylsiloxane (PDMS) is commonly used in medical devices because it is non-toxic and stable against oxidative stress. Relatively high blood platelet adhesion and the need for chemical crosslinking through curing, however, limit its utility. In this research, a biostable PDMS-based polyurethane-urea bearing zwitterion sulfobetaine (PDMS-SB-UU) was synthesized for potential use in the fabrication or coating of blood-contacting devices, such as a conduits, artificial lungs, and microfluidic devices. The chemical structure and physical properties of synthesized PDMS-SB-UU were confirmed by 1H-nuclear magnetic resonance (1H-NMR), X-ray diffraction (XRD), and uniaxial stress-strain curve. In vitro stability of PDMS-SB-UU was confirmed against lipase and 30% H2O2 for 8 weeks, and PDMS-SB-UU demonstrated significantly higher resistance to fibrinogen adsorption and platelet deposition compared to control PDMS. Moreover, PDMS-SB-UU showed a lack of hemolysis and cytotoxicity with whole ovine blood and rat vascular smooth muscle cells (rSMCs), respectively. The PDMS-SB-UU was successfully processed into small-diameter (0.80 ± 0.05 mm) conduits by electrospinning and coated onto PDMS- and polypropylene-based blood-contacting biomaterials due to its unique physicochemical characteristics from its soft- and hard- segments.
Topics: Adsorption; Animals; Biofouling; Blood Platelets; Coated Materials, Biocompatible; Dimethylpolysiloxanes; Fibrinogen; Hemolysis; Platelet Adhesiveness; Polyurethanes; Quaternary Ammonium Compounds; Rats; Sheep; Sulfonic Acids
PubMed: 32785384
DOI: 10.1039/d0tb01220c -
Frontiers in Public Health 2022Microplastic has become a growing environmental problem. A balanced microbial environment is an important factor in human health. This study is the first observational... (Observational Study)
Observational Study
BACKGROUND
Microplastic has become a growing environmental problem. A balanced microbial environment is an important factor in human health. This study is the first observational cross-sectional study focusing on the effects of microplastics on the nasal and gut microbiota in a highly exposed population.
METHODS
We recruited 20 subjects from a Plastic Factory (microplastics high-exposure area) and the other 20 from Huanhuaxi Park (microplastics low-exposure area) in Chengdu, China. We performed the microplastic analysis of soil, air, and intestinal secretions by laser infrared imaging, and microbiological analysis of nasal and intestinal secretions by 16S rDNA sequencing.
RESULTS
The result shows that the detected points of microplastics in the environment of the high-exposure area were significantly more than in the low-exposure area. Polyurethane was the main microplastic component detected. The microplastic content of intestinal secretions in the high-exposure group was significantly higher than in the low-exposure group. Specifically, the contents of polyurethane, silicone resin, ethylene-vinyl acetate copolymer, and polyethylene in the high-exposure group were significantly higher than in the low-exposure group. Moreover, high exposure may increase the abundance of nasal microbiotas, which are positively associated with respiratory tract diseases, such as and , and reduce the abundance of those beneficial ones, such as . Simultaneously, it may increase the abundance of intestinal microbiotas, which are positively associated with digestive tract diseases, such as , and , and reduce the abundance of intestinal microbiotas, which are beneficial for health, such as , and . A combined analysis revealed that high exposure to microplastics may not only lead to alterations in dominant intestinal and nasal microbiotas but also change the symbiotic relationship between intestinal and nasal microbiotas.
CONCLUSION
The results innovatively revealed how microplastics can affect the intestinal and nasal microecosystems.
CLINICAL TRIAL REGISTRATION
ChiCTR2100049480 on August 2, 2021.
Topics: Humans; Microplastics; Plastics; Gastrointestinal Microbiome; Polyurethanes; Cross-Sectional Studies
PubMed: 36388272
DOI: 10.3389/fpubh.2022.1005535 -
Scientific Reports May 2024Repair and reconstruction of the myopectineal orifice area using meshes is the mainstay of surgical treatment of inguinal hernias. However, the limitations of existing...
Repair and reconstruction of the myopectineal orifice area using meshes is the mainstay of surgical treatment of inguinal hernias. However, the limitations of existing meshes are becoming increasingly evident in clinical applications; thus, the idea of using three-dimensionally (3D)-printed biological meshes was put forward. According to the current level of the 3D printing technology and the inherent characteristics of biological materials, the direct use of the 3D printing technology for making biological materials into finished products suitable for clinical applications is not yet supported, but synthetic materials can be first printed into 3D form carriers, compounded with biological materials, and finally made into finished products. The purpose of this study was to develop a technical protocol for making 3D-printed biomesh carriers using polyurethane as a raw material. In our study: raw material, polyurethane; weight, 20-30 g/m; weaving method, hexagonal mesh; elastic tension aspect ratio, 2:1; diameters of pores, 0.1-1 mm; surface area, 8 × 12 cm; the optimal printing layer height, temperature and velocity were 0.1 mm, 210-220 °C and 60 mm/s. Its clinical significance lies in: (1) applied to preoperative planning and design a detailed surgical plan; (2) applied to special types of surgery including patients in puberty, recurrent and compound inguinal hernias; (3) significantly improve the efficiency of doctor-patient communication; (4) it can shorten the operation and recovery period by about 1/3 and can save about 1/4 of the cost for patients; (5) the learning curve is significantly shortened, which is conducive to the cultivation of reserve talents.
Topics: Printing, Three-Dimensional; Polyurethanes; Surgical Mesh; Humans; Hernia, Inguinal; Biocompatible Materials; Herniorrhaphy; Materials Testing
PubMed: 38806559
DOI: 10.1038/s41598-024-63000-3 -
Nature Communications Jun 2018In contrast to most synthetic hydrogels, biological gels are made of fibrous networks. This architecture gives rise to unique properties, like low concentration, high...
In contrast to most synthetic hydrogels, biological gels are made of fibrous networks. This architecture gives rise to unique properties, like low concentration, high porosity gels with a high mechanical responsiveness as a result of strain-stiffening. Here, we used a synthetic polymer model system, based on polyisocyanides, that we crosslinked selectively inside the bundles. This approach allows us to lock in the fibrous network present at the crosslinking conditions. At minimum crosslink densities, we are able to freeze in the architecture, as well as the associated mechanical properties. Rheology and X-ray scattering experiments show that we able to accurately tailor network mechanics, not by changing the gel composition or architecture, but rather by tuning its (thermal) history. Selective crosslinking is a crucial step in making biomimetic networks with a controlled architecture.
Topics: Algorithms; Biomimetics; Cross-Linking Reagents; Cryoelectron Microscopy; Hydrogels; Microscopy, Electron, Scanning; Models, Chemical; Molecular Structure; Polyurethanes; Rheology; Scattering, Small Angle; X-Ray Diffraction
PubMed: 29867185
DOI: 10.1038/s41467-018-04508-x -
Scientific Reports Mar 2022Vascular graft surgeries are often conducted in trauma cases, which has increased the demand for scaffolds with good biocompatibility profiles. Biodegradable scaffolds...
Vascular graft surgeries are often conducted in trauma cases, which has increased the demand for scaffolds with good biocompatibility profiles. Biodegradable scaffolds resembling the extracellular matrix (ECM) of blood vessels are promising vascular graft materials. In the present study, polyurethane (PU) was blended with ECM proteins collagen and elastin (Col-El) and gelatin (Gel) to produce fibrous scaffolds by using the rotary jet spinning (RJS) technique, and their effects on in vitro properties were evaluated. Morphological and structural characterization of the scaffolds was performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Micrometric fibers with nanometric rugosity were obtained. Col-El and Gel reduced the mechanical strength and increased the hydrophilicity and degradation rates of PU. No platelet adhesion or activation was observed. The addition of proteins to the PU blend increased the viability, adhesion, and proliferation of human umbilical vein endothelial cells (HUVECs). Therefore, PU-Col-El and PU-Gel scaffolds are promising biomaterials for vascular graft applications.
Topics: Bioprosthesis; Blood Vessel Prosthesis; Extracellular Matrix; Human Umbilical Vein Endothelial Cells; Humans; Polyurethanes
PubMed: 35347181
DOI: 10.1038/s41598-022-09040-z -
BioMed Research International 2022Polyurethane, as a rubber material, can relieve the load on the ground and provide seismic design for the venue, which is of great significance for sports venues. In...
Polyurethane, as a rubber material, can relieve the load on the ground and provide seismic design for the venue, which is of great significance for sports venues. In order to improve the seismic resistance and abrasion resistance of materials for sports fields and reduce accidents in sports, this article has carried out research on the polyurethane elastomer layered nanocomposites for sports fields and their preparation. Today's world is a challenging era of science and technology. The fields of biotechnology, information, medicine, energy, environment, and national defense and security are closely related to the development of high tech, and the requirements for materials are becoming increasingly diversified. Polymer nanocomposite coating has the dual characteristics of organic and inorganic components. It not only retains the advantages of a polymer but also endows it with versatility. It meets the current application needs. It is a hot spot in today's research. Among them, there are two major problems in the composite process of nanomaterials and polymers: dispersion and compatibility. How to improve the dispersion of nanoparticles and enhance the compatibility between nanoparticles and polymers is an urgent problem to be solved. In the method part, this article introduces a small amount of polyurethane and polyurethane elastomers formed after polyurethane modification and introduces layered compounds and nanocomposites and introduces several models involved in nanomaterials in terms of algorithms. In the analysis part, this paper conducts a comprehensive analysis of the hard segment mass fraction, mechanical properties, thermal decomposition behavior, degradation mechanism, and dynamic mechanical properties. With the increase of GO content, the tensile strength increases significantly and the elongation at break becomes smaller and smaller. When the GO content increases from 0% to 2%, the tensile properties of the WPU film increase from 2.6 MPa to 7.9 MPa and the fracture of the elongation decreased from 201.7% to 62.8%. This shows that the increase in GO content will make the composite material harder and brittle. It can be seen from the experimental results that the preparation of the polyurethane elastomer layered nanocomposite material designed in this paper has a good application effect on sports venues.
Topics: Elastomers; Nanocomposites; Nanoparticles; Polymers; Polyurethanes
PubMed: 36093408
DOI: 10.1155/2022/5152911 -
BioTechniques Jun 2018The goal in the presented study was to develop a simple, fast and accurate method for measuring the surface density of a short peptide sequence bound to a polymeric...
The goal in the presented study was to develop a simple, fast and accurate method for measuring the surface density of a short peptide sequence bound to a polymeric substrate. We analyzed polyurethane samples chemically modified with acrylic acid and polyurethane-grafted peptide (GSGREDVGSG) and investigated the possibility of using the bicinchoninic acid (BCA) assay to determine surface density of the solid-supported peptide. We set the conditions (temperature, time) under which the test should be conducted. We also studied the interaction of the BCA reagent with polyurethane substrate and the effect of drying conditions as well as material type and form on the test response. We have proposed potential factors that might interfere with the BCA assay and chosen the proper control materials.
Topics: Colorimetry; Indicators and Reagents; Linear Models; Oligopeptides; Polyurethanes; Quinolines
PubMed: 29939094
DOI: 10.2144/btn-2018-0004 -
XPS and ToF-SIMS Characterization of New Biodegradable Poly(Peptide-Urethane-Urea) Block Copolymers.Advanced Healthcare Materials May 2022New, linear, segmented poly(peptide-urethane-urea) (PPUU) block copolymers are synthesized and their surface compositions are characterized with angle dependent X-ray...
New, linear, segmented poly(peptide-urethane-urea) (PPUU) block copolymers are synthesized and their surface compositions are characterized with angle dependent X-ray photoelectron spectroscopy (ADXPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). These new PPUU block copolymers contain three types of segments. The soft segment (SS) is poly(caprolactone diol) (PCL). The hard segment is lysine diisocyanate with a hydrazine chain extender. The oligopeptide segment (OPS) contains three types of amino acids (proline, hydroxyproline, and glycine). Incorporation of the OPS into the polyurethane backbone is done to provide a synthetic polymer material with controllable biodegradation properties. As biodegradation processes normally are initiated at the interface between the biomaterial and the living tissue, it is important to characterize the surface composition of biomaterials. ADXPS and ToF-SIMS results show that the surfaces of all four polymers are enriched with the PCL SS, the most hydrophobic component of the three polymer segments.
Topics: Biocompatible Materials; Peptides; Photoelectron Spectroscopy; Polymers; Polyurethanes; Spectrometry, Mass, Secondary Ion; Surface Properties; Urea
PubMed: 34347389
DOI: 10.1002/adhm.202100894 -
Biomaterials Advances Mar 2022Rapid endothelialization helps overcome the limitations of small-diameter vascular grafts. To develop biomimetic non-thrombogenic coatings supporting endothelialization,...
Rapid endothelialization helps overcome the limitations of small-diameter vascular grafts. To develop biomimetic non-thrombogenic coatings supporting endothelialization, medical-grade polyurethane (PU) nanofibrous mats and tubular scaffolds with a diameter below 6 mm prepared by solution blow spinning were coated with polydopamine (PDA), or PDA and gelatin (PDA/Gel). The scaffolds were characterized by scanning electron microscopy, porosity measurement, tensile testing, wettability, Fourier Transform Infrared spectroscopy, and termogravimetric analysis, followed by the measurement of coating stability on the tubular scaffolds. The effect of coating on scaffold endothelialization and hemocompatibility was evaluated using human umbilical vein endothelial cells (HUVECs) and human platelets, showing low numbers of adhering platelets and significantly higher numbers of HUVECs on PDA- and PDA/Gel-coated mats compared to control samples. Tubular PU scaffolds and commercial ePTFE prostheses coated with PDA or PDA/Gel were colonized with HUVECs using radial magnetic cell seeding. PDA/Gel-coated samples achieved full endothelial coverage within 1-3 days post-endothelialization. Altogether, PDA and PDA/Gel coating significantly enhance the endothelialization on the flat surfaces, tubular small-diameter scaffolds, and commercial vascular prostheses. The presented approach constitutes a fast and efficient method of improving scaffold colonization with endothelial cells, expected to work equally well upon implantation.
Topics: Blood Vessel Prosthesis; Coated Materials, Biocompatible; Gelatin; Human Umbilical Vein Endothelial Cells; Humans; Indoles; Polymers; Polyurethanes
PubMed: 35525759
DOI: 10.1016/j.msec.2021.112544