Shigehiro Hashimoto
Abstract
Biological cells adsorb on the scaffold, and show activities: migration, deformation, proliferation, and differentiation. The micro morphology (close to the cell size) on the surface of the scaffold (made by the photolithography technique) is effective for several applications: the marker to trace each ...
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Biological cells adsorb on the scaffold, and show activities: migration, deformation, proliferation, and differentiation. The micro morphology (close to the cell size) on the surface of the scaffold (made by the photolithography technique) is effective for several applications: the marker to trace each cell, and the tool to control the activity of each cell. C2C12 (mouse myoblast) is used in the present study. The typical diameter of the cell is 20 μm, when it is suspended in the medium. The cell aligns along the micro step of the height (> 0.7 μm). The micro-striped groove can control the cell orientation in the flow channel. The aspect ratio of the checkered convexo-concave pattern can control the orientation of cells. When cells are cultured on the thin film (thickness 6 μm, polydimethylsiloxane) with the micro markers at the counter surface, the local contraction movement of myotubes by the electrical-pulse stimulation can be microscopically measured through the transparent scaffold.
S. Fakirov
Abstract
In this short communication, an attempt is undertaken to demonstrate that the widely used practice to call the electrospun polymers from their solutions and melts “polymer nanofibers” is hardly correct for the following reasons. The polymer fibers prepared by means of the common melt-spinning ...
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In this short communication, an attempt is undertaken to demonstrate that the widely used practice to call the electrospun polymers from their solutions and melts “polymer nanofibers” is hardly correct for the following reasons. The polymer fibers prepared by means of the common melt-spinning are characterized by perfect molecular orientation of the parallel aligned macromolecules leading to superior mechanical performance. The electrospun polymers are also flexible cylindrical formations but with macromolecules in isotropic, non-oriented state and distinguished by poor mechanical properties, frequently inferior than those of the same polymer in isotropic state. For this reason, it is suggested to call these materials “fiber-like nanomaterials” instead of “polymer nanofiber”. The real target of the communication is to challenge the electrospinning community to modify the manufacturing process in such a way that the final nanomaterial is characterized by perfect molecular orientation resulting in excellent, typical for polymer fibers mechanical properties, which will offer wide real applications of these nanofibers.
Hannah C. Wells; Hanan R. Kayed; Katie H. Sizeland; Susyn J.R Kelly; Melissa M. Basil-Jones; Richard L. Edmonds; Richard G. Haverkamp
Abstract
Collagen based soft materials are important as medical materials and as consumer products. Strength is a crucial parameter. A better understanding of the structural factors that contribute to strength is sought. Synchrotron based small angle X-ray scattering was used to characterize the collagen ...
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Collagen based soft materials are important as medical materials and as consumer products. Strength is a crucial parameter. A better understanding of the structural factors that contribute to strength is sought. Synchrotron based small angle X-ray scattering was used to characterize the collagen fibril structure and structural arrangement in a range of collagen based materials including leather, surgical scaffold materials and glutaraldehyde stabilized pericardium. Structure was compared with strength and was also characterized during strain. When collagen fibrils are orientated in a highly layered structure (with a high orientation index) the materials exhibit higher tear strength. This applies to leather, surgical scaffolds derived from dermis and pericardium. A more layered structure is found in stronger leather, and depends on the species of the source animal and processing conditions. For surgical scaffolds and stabilized pericardium stronger material is found also to have a more layered structure. In pericardium it is affected by the age of the source animal with younger animals having a more layered fibril arrangement in the pericardium. When collagen based soft materials are strained, the material responds first by a reorientation of the fibrils then by extension of individual fibrils, and this enables them to withstand high stresses.
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