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Dielectric barrier discharge and jet type plasma surface modifications of hybrid polymeric poly (ε-caprolactone)/chitosan scaffolds
No full textDry Modifications of PCL/Chitosan/PCL Tissue Scaffolds
Get PDFNatural polymers are widely used in tissue engineering applications, because of their biocompatibility, biodegradability and solubility in the physiological medium. On the other hand, synthetic polymers are also widely utilized in tissue engineering applications, because they carry no risk of infectious diseases and do not cause immune system reaction. However, the disadvantages of both polymer types block their individual usages as tissue scaffolds efficiently. Therefore, the idea of usage of natural and synthetic polymers together as a single 3D hybrid scaffold which has the advantages of both and the disadvantages of none has been entered to the literature. On the other hand, even though these hybrid structures support the cell adhesion and/or proliferation, various surface modification techniques applied to the surfaces of them to create topographical changes on the surfaces and to obtain reactive functional groups required for the immobilization of biomolecules, especially on the surfaces of synthetic polymers in order to improve cell adhesion and proliferation. In a study presented here, to improve the surface functionality and topography of the layer by layer electrospun 3D poly-epsilon-caprolactone/chitosan/poly-epsilon-caprolactone hybrid tissue scaffolds by using atmospheric pressure plasma method, thus to improve cell adhesion and proliferation of these tissue scaffolds were aimed. The formation/creation of the functional hydroxyl and amine groups and topographical changes on the surfaces of scaffolds were realized by using two different atmospheric pressure plasma systems (nozzle type and dielectric barrier discharge (DBD) type) carried out under different gas medium (air, Ar+O2, Ar+N2). The plasma modification time and distance for the nozzle type plasma system as well as the plasma modification time and the gas flow rate for DBD type plasma system were optimized with monitoring the changes in surface hydrophilicity by using contact angle measurements. The topographical and chemical characterizations of these modified biomaterials' surfaces were carried out with SEM and ESCA, respectively. The results showed that the atmospheric pressure plasma modifications carried out with both nozzle type plasma and DBD plasma caused topographical and functionality changes on the surfaces of the layer by layer electrospun tissue scaffolds. However, the shelf life studies indicated that the hydrophilicity introduced to the surfaces was mainly because of the functionality changes. Therefore, according to the optimized results, samples treated with nozzle type air plasma modification applied for 9 minutes from a distance of 17 cm and Ar+O2 DBD plasma modification applied for 1 minute under 70 cm3/min O2 flow rate were found to have the highest hydrophilicity compared to pristine samples
Materials and Processes for Treatment of Microbiological Pollution in Water
No full textClean and safe water is vital for the life and health of human beings. However, there are still millions of people around the world with inadequate clean water sources. Microbiological pollution is one of the most concerned water pollutants and is the crucial cause of waterborne diseases like diarrhea, resulting in about two million deaths annually due to severe dehydration (WHO in Guidelines for drinking-water quality. Incorporating the first addendum, WHO, Geneva, 2017). It is critical to develop methods using advanced materials and process to mitigate contaminants from water resources. Production of safe water usually involves disinfection and decontamination processes. Conventional disinfection process, such as chlorination, is challenged by the formation of disinfection by-products. Furthermore, the presence of emerging pathogenic, that resist conventional water treatment techniques, raised the crucial necessity for emerging materials and techniques for treating water from microbiological pollution (Shannon et al. in Nature 452:301–310, 2008). This chapter describes bacterial, viral, and protozoal microbiological pollution in water supplies and the application of emerging materials and techniques to eliminate such contaminations. © 2021, Springer Nature Switzerland AG
Development of Antibacterial Composite Electrospun Chitosan-Coated Polypropylene Materials
No full textCore/Shell Glycine-Polyvinyl Alcohol/Polycaprolactone Nanofibrous Membrane Intended for Guided Bone Regeneration: Development and Characterization
No full textGlycine (Gly), which is the simplest amino acid, induces the inflammation response and enhances bone mass density, and particularly its β polymorph has superior mechanical and piezoelectric properties. Therefore, electrospinning of Gly with any polymer, including polyvinyl alcohol (PVA), has a great potential in biomedical applications, such as guided bone regeneration (GBR) application. However, their application is limited due to a fast degradation rate and undesirable mechanical and physical properties. Therefore, encapsulation of Gly and PVA fiber within a poly(ε-caprolactone) (PCL) shell provides a slower degradation rate and improves the mechanical, chemical, and physical properties. A membrane intended for GBR application is a barrier membrane used to guide alveolar bone regeneration by preventing fast-proliferating cells from growing into the bone defect site. In the present work, a core/shell nanofibrous membrane, composed of PCL as shell and PVA:Gly as core, was developed utilizing the coaxial electrospinning technique and characterized morphologically, mechanically, physically, chemically, and thermally. Moreover, the characterization results of the core/shell membrane were compared to monolithic electrospun PCL, PVA, and PVA:Gly fibrous membranes. The results showed that the core-shell membrane appears to be a good candidate for GBR application with a nano-scale fiber of 412 ± 82 nm and microscale pore size of 6.803 ± 0.035 μm. Moreover, the wettability of 47.4 ± 2.2° contact angle (C.A) and mechanical properties of 135 ± 3.05 MPa average modulus of elasticity, 4.57 ± 0.04 MPa average ultimate tensile stress (UTS), and 39.43% ± 0.58% average elongation at break are desirable and suitable for GBR application. Furthermore, the X-ray diffraction (XRD) and transmission electron microscopy (TEM) results exhibited the formation of β-Gly
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