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1.
Molecules ; 26(5)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652616

RESUMO

The main aims of the research were to produce efficient nanofibrous filters with long-term antibacterial properties and to confirm the functionality of samples under real filtration conditions. A polyurethane solution was modified by micro- or nanoparticles of copper oxide in order to juxtapose the aggregation tendency of particles depending on their size. Modified solutions were electrospun by the Nanospider technique. The roller spinning electrode with a needle surface and static wire electrode were used for the production of functionalized nanofibers. The antibacterial properties of the modified nanofibrous layers were studied under simulated conditions of water and air filtration. Particular attention was paid to the fixation mechanism of modifiers in the structure of filters. It was determined that the rotating electrode with the needle surface is more efficient for the spinning of composite solutions due to the continuous mixing and the avoidance of particle precipitation at the bottom of the bath with modified polyurethane. Moreover, it was possible to state that microparticles of copper oxide are more appropriate antimicrobial additives due to their weaker aggregation tendency but stronger fixation in the fibrous structure than nanoparticles. From the results, it is possible to conclude that nanofibers with well-studied durable antibacterial properties may be recommended as excellent materials for water and air filtration applications.


Assuntos
Antibacterianos/química , Infecções Bacterianas/tratamento farmacológico , Nanofibras/química , Nanopartículas/química , Antibacterianos/farmacologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Cobre/química , Humanos , Membranas Artificiais , Poliuretanos/química
2.
Molecules ; 26(4)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670378

RESUMO

Biodegradable and antimicrobial waterborne polyurethane dispersions (PUDs) and their casted solid films have recently emerged as important alternatives to their solvent-based and non-biodegradable counterparts for various applications due to their versatility, health, and environmental friendliness. The nanoscale morphology of the PUDs, dispersion stability, and the thermomechanical properties of the solid films obtained from the solvent cast process are strongly dependent on several important parameters, such as the preparation method, polyols, diisocyanates, solid content, chain extension, and temperature. The biodegradability, biocompatibility, antimicrobial properties and biomedical applications can be tailored based on the nature of the polyols, polarity, as well as structure and concentration of the internal surfactants (anionic or cationic). This review article provides an important quantitative experimental basis and structure evolution for the development and synthesis of biodegradable waterborne PUDs and their solid films, with prescribed macromolecular properties and new functions, with the aim of understanding the relationships between polymer structure, properties, and performance. The review article will also summarize the important variables that control the thermomechanical properties and biodegradation kinetics, as well as antimicrobial and biocompatibility behaviors of aqueous PUDs and their films, for certain industrial and biomedical applications.


Assuntos
Anti-Infecciosos/química , Plásticos Biodegradáveis/química , Polímeros/química , Poliuretanos/química , Ânions/química , Ânions/uso terapêutico , Anti-Infecciosos/uso terapêutico , Plásticos Biodegradáveis/uso terapêutico , Humanos , Polímeros/uso terapêutico , Poliuretanos/uso terapêutico , Solventes/química , Tensoativos/química , Tensoativos/uso terapêutico , Água/química
3.
ACS Appl Mater Interfaces ; 13(6): 7567-7579, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33538168

RESUMO

Evidence has shown that hospital surfaces are one of the major vehicles of nosocomial infections caused by drug-resistant pathogens. Smart surface coatings presenting multiple antimicrobial activity mechanisms have emerged as an advanced approach to safely prevent this type of infection. In this work, industrial waterborne polyurethane varnish formulations containing for the first time cationic polymeric biocides (SPBs) combined with photosensitizer curcumin were developed to afford contact-active and light-responsive antimicrobial surfaces. SPBs were prepared by atom transfer radical polymerization, which allows control over the polymer features that influence antimicrobial efficiency (e.g., molecular weight), while natural curcumin was employed to impart photodynamic activity to the surface. Antibacterial testing against Gram-negative Escherichia coli revealed that glass surfaces coated with the new formulations displayed photokilling effect under white-light (42 mW/cm2) irradiation within only 15 min of exposure. In addition, it was observed a combined antimicrobial effect between the two biocides (cationic SPB and curcumin), with a higher reduction in the number of viable bacteria observed for the surfaces containing cationic SPB/curcumin mixtures in comparison with the one obtained for surfaces only with polymer or without biocides. The waterborne industrial varnish formulations allowed the formation of homogeneous films without the need for addition of a coalescing agent, which can be potentially applied in diverse surface substrates to reduce bacterial transmission infections in healthcare environments.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Luz , Poliuretanos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Composição de Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Poliuretanos/síntese química , Poliuretanos/química , Propriedades de Superfície
4.
J Mater Chem B ; 9(5): 1384-1394, 2021 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-33459744

RESUMO

Silicone elastomer coatings have attracted increasing attention owing to their eco-friendly nature, excellent fouling release ability and drag-reducing property. However, the poor mechanical properties and lack of fouling resistance limit their applications. Herein, a silicone-based polyurethane with 2-ureido-4[1H]-pyrimidinone (UPy) and amphiphilic pendant chains is reported. The UPy groups and urethane can form hydrogen bonds with various substrates so that the coating has significantly improved adhesion strength (0.9-3.0 MPa) compared with the PDMS elastomer (0.3-0.4 MPa). Moreover, the quadruple hydrogen bonding between UPy moieties allows the polymer to have excellent self-healing ability and high elasticity. The modified polymeric coating has low surface energy (24 mJ m-2) and low elastic modulus (1.9 MPa), so it exhibits good fouling release performance. Besides, the amphiphilic side chains can effectively resist protein adsorption and adhesion of the marine bacteria Pseudomonas sp. and diatom Navicula incerta. The novel design can improve the resistance of silicone coating to biofouling and mechanical forces and is promising for high-performance antifouling coatings.


Assuntos
Poliuretanos/química , Silicones/química , Animais , Incrustação Biológica , Peixes , Propriedades de Superfície
5.
Carbohydr Polym ; 256: 117507, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33483029

RESUMO

A series of vegetable oil-based waterborne polyurethane composites were prepared through construction of novel semi-interpenetrating polymers network using carboxymethyl chitosan (CA) as the secondary polymer phase. The effects of CA contents on storage stability, and particle size distribution of the composite dispersions and thermal stability, mechanical properties and surface wettability of composite films were investigated and discussed. The results showed that the composite dispersions displayed excellent storage stability and the biomass contents of resulting films were high up to 80 %. A significant increase in crosslinking density and glass transition temperature of the composite films were observed as the CA contents increased, which was attributed to the increasing hard segment of films and strong hydrogen bonding interaction between polyurethanes and CA. This work provided a simple method to tailor the performance of environmentally friendly vegetable oil-based waterborne polyurethane, which could find application in the field of coatings, adhesives, ink and so on.


Assuntos
Óleo de Rícino/química , Quitosana/análogos & derivados , Poliuretanos/química , Água/química , Quitosana/química , Estabilidade de Medicamentos , Humanos , Ligação de Hidrogênio , Teste de Materiais , Tamanho da Partícula , Transição de Fase , Resistência à Tração , Temperatura de Transição , Molhabilidade
6.
Int J Pharm ; 595: 120243, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33484923

RESUMO

Cardiovascular diseases constitute a number of conditions which are the leading cause of death globally. To combat these diseases and improve the quality and duration of life, several cardiac implants have been developed, including stents, vascular grafts and valvular prostheses. The implantation of these vascular prosthesis has associated risks such as infection or blood clot formation. In order to overcome these limitations medicated vascular prosthesis have been previously used. The present paper describes a 3D printing method to develop medicated vascular prosthesis using fused deposition modelling (FDM) technology. For this purpose, rifampicin (RIF) was selected as a model molecule as it can be used to prevent vascular graft prosthesis infection. Thermoplastic polyurethane (TPU) and RIF were combined using hot melt extrusion (HME) to obtain filaments containing RIF concentrations ranging between 0 and 1% (w/w). These materials are capable of providing RIF release for periods ranging between 30 and 80 days. Moreover, TPU-based materials containing RIF were capable of inhibiting the growth of Staphylococcus aureus. This behaviour was observed even for TPU-based materials containing RIF concentrations of 0.1% (w/w). TPU containing 1% (w/w) of RIF showed antimicrobial properties even after 30 days of RIF release. Alternatively, these methods were used to prepare dipyridamole containing TPU filaments. Finally, using a dual extrusion 3D printer vascular grafts containing both drugs were prepared.


Assuntos
Antibacterianos/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Poliuretanos/química , Rifampina/farmacocinética , Tecnologia Farmacêutica/métodos , Células Sanguíneas/efeitos dos fármacos , Prótese Vascular/efeitos adversos , Preparações de Ação Retardada/química , Dipiridamol/farmacocinética , Liberação Controlada de Fármacos , Desenho de Equipamento/métodos , Células Endoteliais da Veia Umbilical Humana , Humanos , Inibidores da Agregação de Plaquetas/farmacocinética , Poliuretanos/uso terapêutico , Impressão Tridimensional , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/efeitos dos fármacos , Trombose/etiologia , Trombose/prevenção & controle
7.
ACS Appl Mater Interfaces ; 13(3): 4545-4552, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33459023

RESUMO

In this study, polydimethylsiloxane (PDMS)/polythiourethane (PTU) composite reinforced with tetrapodal shaped micro-nano ZnO particles (t-ZnO) was successfully produced by a versatile, industrially applicable polymer blending process. On the surface of this composite, PDMS is distributed in the form of microdomains embedded in a PTU matrix. The composite inherited not only good mechanical properties originating from PTU but also promising fouling-release (FR) properties due to the presence of PDMS on the surface. It was shown that the preferential segregation of PDMS domains at the polymer/air interface could be attributed to the difference in the surface free energy of PDMS and PTU. The PDMS microdomains at the PTU/air interface significantly reduced the barnacle adhesion strength on the composite. Both the pseudo- and natural barnacle adhesion strength on the composite was approximately 0.1 MPa, similar to that on pure PDMS. The pseudo-barnacle adhesion on reference surfaces AlMg3 and PTU reached approximately 4 and 6 MPa, respectively. Natural barnacles could not be removed intact from AlMg3 and PTU surfaces without breaking the shell, indicating that the adhesion strength was higher than the mechanical strength of a barnacle shell (approximately 0.4 MPa). The integrity of PDMS microdomains was maintained after 12 months of immersion in seawater and barnacle removal. No surface deteriorations were found. In short, the composite showed excellent potential as a long-term stable FR coating for marine applications.


Assuntos
Incrustação Biológica/prevenção & controle , Dimetilpolisiloxanos/química , Poliuretanos/química , Thoracica/citologia , Óxido de Zinco/química , Ar/análise , Animais , Nanopartículas/química , Transição de Fase , Propriedades de Superfície
8.
J Mater Chem B ; 9(3): 832-845, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33347521

RESUMO

Peritendinous adhesions cause chronic pain and disability. Leading causes are trauma to tendons and surrounding tissues and immobilization after surgery. Adhesions occur between 24 hours to 6 weeks after surgery. Anti-adhesion barriers are currently the best option available to prevent peritendinous adhesions, but are ineffective and difficult to use. We developed an anti-adhesive membrane that can be easily applied during tendon surgery and effectively prevent adhesions. The membrane is based on a new triblock copolymer, is non-toxic, can be bio-eliminated, and has a degradation rate of more than 6 weeks for optimal anti-adhesion effect. We synthesized and characterized poly(ether urethane) (PEU) from poly(ethylene glycol). Triblock copolymers poly(lactic acid)-PEU-poly(lactic acid) (PLA-PEU-PLA) were then synthesized from PEU with PLA blocks of different lengths, and characterized. The membranes were shaped by hot molding and their mechanical properties, contact angle, water uptake, the kinetics of in vitro degradation and cytotoxicity were studied. Mechanical properties were developed according to the needs of orthopaedic surgeons. Results showed that membranes maintained their filmogenic integrity, have a degradation rate for optimal adhesion prevention, can be bioeliminated and biocompatible suggesting that they could be safely and effectively used as anti-adhesion orthopaedic devices. These results support the use of PLA-PEU-PLA membranes as a medical device, however, the effectiveness of the membranes in vivo needs to be further evaluated. A future study using an in vivo rat model of postoperative peritendinous adhesions is currently being developed.


Assuntos
Materiais Biocompatíveis/química , Ortopedia , Poliésteres/química , Poliuretanos/química , Aderências Teciduais/prevenção & controle , Animais , Materiais Biocompatíveis/síntese química , Linhagem Celular , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície , Temperatura
9.
ACS Appl Mater Interfaces ; 13(1): 2100-2109, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33347284

RESUMO

Sensitive and flexible sensors capable of monitoring physiological signals of human body for healthcare have been developed in recent years. It is still a challenge to fabricate a wearable sensor-integrated multifunctional performances and a good fit to human body. Here, an rGO and pen ink/PVA-layered strain-humidity sensor based on MS fabric is prepared through a cost-effective and scalable solution process. The conductive fabric as a strain sensor has a workable strain range (∼300%), ultrahigh sensitivity (maximum gauge factor of 492.8), great comfort, and long-term stability. Notably, a step increase in relative resistance variation will be achieved by controlling the coverage of an ink layer. Moreover, the reliable linear humidity-dependent resistance void of hysteresis and excellent repeatability renders conductive fabrics an opportunity as humidity sensors. Based on these superior multifunctions, the resultant conductive fabric can be applied to detect both human motions and skin humidity, showing potential in applications of wearable electronics for professional athletes.


Assuntos
Grafite/química , Monitorização Fisiológica/instrumentação , Poliuretanos/química , Álcool de Polivinil/química , Têxteis , Dispositivos Eletrônicos Vestíveis , Humanos , Umidade , Tinta , Movimento , Fenômenos Fisiológicos da Pele , Estresse Mecânico
10.
Microvasc Res ; 133: 104073, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32949575

RESUMO

In this study, the angiogenic capacity of human endothelial cells was studied after being plated on the surface of polyurethane-poly caprolactone (PU/PCL) scaffolds for 72 h. In this study, cells were designated into five different groups, including PU, PU/PCL (2:1), PU/PCL (1:1); PU/PCL (1:2); and PCL. Data revealed that the PU/PCL (2:1) composition had a higher modulus and breakpoint in comparison with the other groups (p < 0.05). Compared to the other groups, the PU/PCL scaffold with a molar ratio of 2:1 had lower the contact angle θ and higher tensile stress (p < 0.05). The mean size of the PU nanofibers was reduced after the addition of PCL (p < 0.05). Based on our data, the culture of endothelial cells on the surface of PU/PCL (2:1) did not cause nitrosative stress and cytotoxic effects under static conditions compared to cells plated on a conventional plastic surface (p > 0.05). Based on data from the static condition, we fabricated a tubular PU/PCL (2:1) construct for six-day dynamic cell culture inside loop air-lift bioreactors. Scanning electron microscopy showed the attachment of endothelial cells to the luminal surface of the PU/PCL scaffold. Cells were flattened and aligned under the culture medium flow. Immunofluorescence imaging showed the attachment of cells to the luminal surface indicated by blue nuclei on the luminal surface. These data demonstrated that the application of PU/PCL substrate could stimulate endothelial cells activity under static and dynamic conditions.


Assuntos
Células Endoteliais da Veia Umbilical Humana/fisiologia , Nanofibras , Poliésteres/química , Poliuretanos/química , Tecidos Suporte , Reatores Biológicos , Adesão Celular , Técnicas de Cultura de Células , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Módulo de Elasticidade , Células Endoteliais da Veia Umbilical Humana/ultraestrutura , Humanos , Resistência à Tração , Fatores de Tempo
11.
Carbohydr Polym ; 251: 117035, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142593

RESUMO

A biomimetic-based approaches, especially with artificial scaffolding, have established great potential to provide tissue regeneration capacity and an effective way to bridge the gap between host cell responses and organ demands. However, the synthesis of biomaterial is most efficient when the functional behavior involved most resembles the natural extracellular matrix. Here, a fibrous scaffold was engineered by integrating zein and chitosan (CS) in to polyurethane (PU) associated with functionalized multiwalled carbon nanotubes (fMWCNTs) as a bone cell repair material. The chitosan-based, tissue-engineered scaffold containing 0.1 mg/mL fMWCNTs shows potent synergistic results where improved biomechanical strength, hydrophilicity and antibacterial efficacy produce a scaffold akin to a truly natural extracellular matrix found in the bone cell microenvironments. The scaffold enables rapid cell-to-cell communication through a bio-interface and greatly promotes the regenerative effect of pre-osteoblast (MC3T3-E1) which is reflected in terms of cell growth, proliferation, and differentiation in our in vitro experiments. Alizarin red staining analysis, alkaline phosphatase activity, and Western blotting also confirm the nucleation of hydroxyapatite (HA) nanocrystals and the expression of osteogenic protein markers, all of which indicate the scaffold's excellent osteoinductive properties. These results suggest that this precisely engineered PU/Zein/CS-fMWCNTs fibrous scaffold possesses suitable biological behavior to act as an artificial bone extracellular matrix that will ensure bone cell regeneration while contributing numerous benefits to the field of artificial bone grafts.


Assuntos
Materiais Biocompatíveis , Regeneração Óssea , Quitosana , Osteogênese , Engenharia Tecidual , Tecidos Suporte , Zeína , Animais , Materiais Biocompatíveis/química , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Microambiente Celular , Quitosana/química , Camundongos , Nanotubos de Carbono/química , Osteoblastos , Poliuretanos/química , Zeína/química
12.
Carbohydr Polym ; 254: 117478, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357930

RESUMO

Waterborne polyurethanes (WBPUs) have been proposed as ecofriendly elastomers with several applications in coatings and adhesives. WBPU's physicochemical properties can be enhanced by the addition of cellulose nanocrystals (CNCs). The way CNCs are isolated has a strong effect on their properties and can determine their role as reinforcement. In this work, CNCs produced using ancestral endoglucanase (EnCNCs) were used as reinforcement for WBPU and compared with CNC produced by sulfuric acid hydrolysis (AcCNC). The enzymatic method produced highly thermostable and crystalline CNCs. The addition of small contents of EnCNCs improved the thermomechanical stability and mechanical properties of WBPUs, even better than commercial AcCNCs. Besides, WBPU reinforced by adding EnCNCs was studied as a coating for paper materials, increasing its abrasion resistance and as electrospun nanocomposite mats where EnCNCs helped maintaining the morphology of the fibers.


Assuntos
Celulase/química , Celulose/química , Química Verde , Nanopartículas/química , Poliuretanos/química , Adesivos/química , Celulase/genética , Celulase/metabolismo , Materiais de Construção/análise , Humanos , Hidrólise , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanopartículas/ultraestrutura , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ácidos Sulfúricos/química , Água/química
13.
Int J Mol Sci ; 22(1)2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33374754

RESUMO

Two polyol raw materials were obtained in the conducted research, one based on metasilicic acid (MSA), the other based on poly(lactic acid) (PLA) waste. The obtained polyols were characterized in terms of their applicability for the production of rigid polyurethane foams (RPUFs). Their basic analytical properties (hydroxyl number, acid number, elemental analysis) and physicochemical properties (density, viscosity) were determined. The assumed chemical structure of the obtained new compounds was confirmed by performing FTIR and 1H NMR spectroscopic tests. Formulations for the synthesis of RPUFs were developed on the basis of the obtained research results. A mixture of polyols based on MSA and PLA in a weight ratio of 1:1 was used as the polyol component in the polyurethane formulation. The reference foam in these tests was a foam that was synthesized only on the basis of MSA-polyol. The obtained RPUFs were tested for basic functional properties (apparent density, compressive strength, water absorption, thermal conductivity coefficient etc.). Susceptibility to biodegradation in soil environment was also tested. It was found that the use of mixture of polyols based on MSA and PLA positively affected the properties of the obtained foam. The polyurethane foam based on this polyol mixture showed good thermal resistance and significantly reduced flammability in comparison with the foam based MSA-polyol. Moreover, it showed higher compressive strength, lower thermal conductivity and biodegradability in soil. The results of the conducted tests confirmed that the new foam was characterized by very good performance properties. In addition, this research provides information on new waste management opportunities and fits into the doctrine of sustainable resource management offered by the circular economy.


Assuntos
Plásticos Biodegradáveis/síntese química , Poliésteres/química , Polímeros/química , Poliuretanos/química , Força Compressiva , Silicatos/química
14.
Molecules ; 26(1)2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33379358

RESUMO

A star polymer with a polyhedral oligomeric silsesquioxanne (POSS) core and poly(ethylene glycol) (PEG) vertex groups is incorporated in a polyurethane with flexible hard segments in-situ during the polymerization process. The blends are studied in terms of morphology, molecular dynamics, and charge mobility. The methods utilized for this purpose are scanning electron and atomic force microscopies (SEM, AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and to a larger extent dielectric relaxation spectroscopy (DRS). It is found that POSS reduces the degree of crystallinity of the hard segments. Contrary to what was observed in a similar system with POSS pendent along the main chain, soft phase calorimetric glass transition temperature drops as a result of plasticization, and homogenization of the soft phase by the star molecules. The dynamic glass transition though, remains practically unaffected, and a hypothesis is formed to resolve the discrepancy, based on the assumption of different thermal and dielectric responses of slow and fast modes of the system. A relaxation α', slower than the bulky segmental α and common in polyurethanes, appears here too. A detailed analysis of dielectric spectra provides some evidence that this relaxation has cooperative character. An additional relaxation g, which is not commonly observed, accompanies the Maxwell Wagner Sillars interfacial polarization process, and has dynamics similar to it. POSS is found to introduce conductivity and possibly alter its mechanism. The study points out that different architectures of incorporation of POSS in polyurethane affect its physical properties by different mechanisms.


Assuntos
Compostos de Organossilício/química , Polietilenoglicóis/química , Poliuretanos/química , Materiais Biocompatíveis/química , Varredura Diferencial de Calorimetria/métodos , Condutividade Elétrica , Vidro/química , Dureza , Polímeros/química , Temperatura , Difração de Raios X/métodos
15.
Molecules ; 26(1)2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33379374

RESUMO

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbonated spherulites (up to 60% w/w) was synthesized and investigated with regard to an application as bone substitute in dental and orthodontic application. After foaming the composite material, a predominantly interconnecting porous structure is obtained, which can be easily machined. The compressive strength of the foamed composites increases with raising calcium carbonate content and decreasing calcium carbonate particle size. When stored in an aqueous medium, there is a decrease in pressure stability of the composite, but this decrease is smaller the higher the proportion of the calcium carbonate component is. In vitro cytocompatibility studies of the foamed composites on MC3T3-E1 pre-osteoblasts revealed an excellent cytocompatibility. The in vitro degradation behaviour of foamed composite is characterised by a continuous loss of mass, which is slower with higher calcium carbonate contents. In a first pre-clinical pilot trial the foamed composite bone substitute material (fcm) was successfully evaluated in a model of vertical augmentation in an established animal model on the calvaria and on the lateral mandible of pigs.


Assuntos
Materiais Biocompatíveis/administração & dosagem , Desenvolvimento Ósseo/efeitos dos fármacos , Carbonato de Cálcio/administração & dosagem , Poliésteres/administração & dosagem , Poliuretanos/administração & dosagem , Células 3T3 , Animais , Materiais Biocompatíveis/química , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/administração & dosagem , Substitutos Ósseos/química , Carbonato de Cálcio/química , Linhagem Celular , Força Compressiva/efeitos dos fármacos , Feminino , Camundongos , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Projetos Piloto , Poliésteres/química , Poliuretanos/química , Porosidade , Suínos , Tecidos Suporte/química
16.
J Med Life ; 13(2): 195-199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32742513

RESUMO

Polyurethane nano- and micro-structures have been studied intensively in the last decade as drug delivery systems for various herbal extracts as well as pure active biological substances. Their biocompatibility, haemocompatibility, safe degradation, and low-cost production are just a few advantages of these materials that were already used in numerous medical applications (catheters, surgical drapes, wound dressing). The primary purposes of this study include obtaining empty polyurethane microstructures and the assessment of their modifications in media with different pH values. A mixture of two aliphatic diisocyanates and an aqueous phase based on a polyether were used during the synthesis process. The size, homogeneity, and surface charge were studied using a Cordouan Technol. Zetasizer, while the pH measurements were conducted with a portable pH Meter Checker®, Hanna Instruments. The results showed the obtaining of an almost homogeneous sample containing microstructures with sizes ranging between 139 and 151 nm, with a pH value of approximately 6.78 and a Zeta potential of 24.6. Expected decreases in microparticles' sizes were observed in all types of media during a 15-days experiment, but the process was accelerated by a low pH when an increase of the Zeta potential value was noticed as well. Our data provide new information about the degradation process of the polyurethane microstructures on the one hand and the drug release rate of these materials when used as drug carriers, on the other hand.


Assuntos
Portadores de Fármacos/química , Poliuretanos/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Eletricidade Estática
17.
ACS Appl Mater Interfaces ; 12(31): 34723-34727, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32657566

RESUMO

SARS-CoV-2, the virus that causes the disease COVID-19, remains viable on solids for periods of up to 1 week, so one potential route for human infection is via exposure to an infectious dose from a solid. We have fabricated and tested a coating that is designed to reduce the longevity of SARS-CoV-2 on solids. The coating consists of cuprous oxide (Cu2O) particles bound with polyurethane. After 1 h on coated glass or stainless steel, the viral titer was reduced by about 99.9% on average compared to the uncoated sample. An advantage of a polyurethane-based coating is that polyurethane is already used to coat a large number of everyday objects. Our coating adheres well to glass and stainless steel as well as everyday items that people may fear to touch during a pandemic, such as a doorknob, a pen, and a credit card keypad button. The coating performs well in the cross-hatch durability test and remains intact and active after 13 days of being immersed in water or after exposure to multiple cycles of exposure to the virus and disinfection.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/genética , Pandemias , Pneumonia Viral/genética , Betacoronavirus/patogenicidade , Cobre/química , Cobre/metabolismo , Infecções por Coronavirus/virologia , Humanos , Pneumonia Viral/virologia , Poliuretanos/química , Poliuretanos/metabolismo , Propriedades de Superfície
18.
Nat Commun ; 11(1): 3530, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669576

RESUMO

Resistance change under mechanical stimuli arouses mass operational heat, damaging the performance, lifetime, and reliability of stretchable electronic devices, therefore rapid thermal heat dissipating is necessary. Here we report a stretchable strain sensor with outstanding thermal management. Besides a high stretchability and sensitivity testified by human motion monitoring, as well as long-term durability, an enhanced thermal conductivity from the casted thermoplastic polyurethane-boron nitride nanosheets layer helps rapid heat transmission to the environments, while the porous electrospun fibrous thermoplastic polyurethane membrane leads to thermal insulation. A 32% drop of the real time saturated temperature is achieved. For the first time we in-situ investigated the dynamic operational temperature fluctuation of stretchable electronics under repeating stretching-releasing processes. Finally, cytotoxicity test confirms that the nanofillers are tightly restricted in the nanocomposites, making it harmless to human health. All the results prove it an excellent candidate for the next-generation of wearable devices.


Assuntos
Técnicas Biossensoriais/instrumentação , Movimento , Dispositivos Eletrônicos Vestíveis , Técnicas Biossensoriais/métodos , Compostos de Boro/química , Elastômeros , Eletrônica , Células HEK293 , Temperatura Alta , Humanos , Nanocompostos , Nanoestruturas , Polímeros/química , Poliuretanos/química , Reprodutibilidade dos Testes
19.
Biofouling ; 36(2): 200-209, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32253933

RESUMO

Biodegradable polymers are promising binders and carriers for natural antifoulants. In the present study, an antifouling (AF) coating was developed by adding a non-toxic AF compound (butenolide) to a bio-based and biodegradable poly(lactic acid)-based polyurethane. Mass loss measurement showed that the polymer degraded in seawater at a rate of 0.013 mg cm-2 day-1. Measurements showed that butenolide was released from the coatings into seawater over a period of at least three months. Both the concentration of butenolide in the coatings and the ambient temperature determined the release rate of butenolide. The results further demonstrate that incorporating rosin into the coatings increase the self-renewal rate of the polymer and facilitated the long-term release of butenolide from the coating. The results show that poly(lactic acid)-based polyurethane is a suitable polymer for butenolide-based AF coatings.


Assuntos
4-Butirolactona/análogos & derivados , Plásticos Biodegradáveis/química , Incrustação Biológica/prevenção & controle , Desinfetantes/química , Poliésteres/química , Poliuretanos/química , 4-Butirolactona/química , Desinfetantes/análise , Água do Mar/química , Propriedades de Superfície
20.
Artigo em Inglês | MEDLINE | ID: mdl-32145637

RESUMO

The US Environmental protection agency (EPA) has published guidance that includes test procedures for evaluating indoor exposure to chemicals from products. One of the test procedures represents the migration test for evaluating potential dermal exposure from home furniture. Such an evaluation involves the chemical measurement of the sweat which is currently unavailable in the literature. The objective of this project was to develop and validate an analytical method for quantification of migration of 4,4'-methylenediphenyl diisocyanate (MDI), 2,6-toluene diisocyanate (2,6-TDI) and 2,4-toluene diisocyanate (2,4-TDI) from a polyurethane (PU) flexible foam to artificial sweat that meets the recommendations of the EPA test protocol. Following the EPA protocol, six synthetic sweat solutions were prepared and used in evaluation of isocyanate recovery performance. The migration tests were conducted using five foam types that were chosen and supplied by PU foam manufacturers to represent the types most commonly found in commercial products, and with formulations anticipated to have the highest potential residual TDI or MDI. Migration tests were conducted using glass fiber filters (GFF) coated with 1-(2-methoxyphenyl)piperazine (1,2-MP) and analyzed using HPLC equipped with a UV detector for quantification and a MS detector to qualify peaks. The detection limits of the method were 0.002 µg/mL for 2,6-TDI, 0.011 µg/mL for 2,4-TDI, and 0.003 µg/mL for MDI. Quantification limits were 0.006 µg/mL, 0.037 µg/mL, and 0.010 µg/mL, respectively. The recovery tests on a Teflon surface for 5 of the 6 EPA-recommended synthetic sweat solutions indicate the recovery percentage was approximately 80% for diisocyanates. Recovery for the sixth sweat solution was low, approximately 30%. TDI and MDI migration was not observed when testing was conducted on foam samples.


Assuntos
Isocianatos/química , Pintura/efeitos adversos , Poliuretanos/química , Suor/química , Tolueno 2,4-Di-Isocianato/química , Poluentes Ocupacionais do Ar/efeitos adversos , Poluentes Ocupacionais do Ar/química , Cromatografia Líquida de Alta Pressão , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Humanos , Isocianatos/efeitos adversos , Movimento , Propriedades de Superfície , Espectrometria de Massas em Tandem , Tolueno 2,4-Di-Isocianato/efeitos adversos
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