Manufacturing a Biomimetic Biorecator in Cardiac Tissue Engineering

Introduction: The direct approach of cardiac tissue engineering is to mimic the natural tissue of heart, considering the significant role of scaffolding and mechanical simulation. Methods: To achieve this purpose, a composite Polycaprolactone (PCL)/Gelatin electrospun scaffold with a ratio of 70:30 and with the most similarities to the cardiac extracellular matrix was fabricated with aligned nanofibers. The scaffold was evaluated using scanning electron microscopy (SEM), mechanical strength analysis, and contact angle test. To simulate the cardiac contraction, a developed Mechanical Loading Device (Bioreactor) was designed to apply a mechanical load with a specific frequency and tensile rate values in the direction of aligned nanofibers due to simulating natural cardiac tissue. Results: Based on our results from the contact angle and mechanical strength tests, we concluded that our designed scaffold has appropriate adhesion and strength to use as cardiac scaffold and is suitable for imposing the frequency of 1Hz and 10% strain. The Bioreactor also worked properly in producing the required frequency, tensile rate and temperature. Conclusion: Since an essential difference between cardiomyocytes and other cells is their contraction, manufacturing a biomimetic bioreactor to simulate the normal cardiac contraction of cardiomyocytes and their required temperature to be survived in-vitro could be a promising approach in cardiac tissue engineering.

Mechanical and Dielectric Properties of Aligned Electrospun Fibers

This review paper examines the current state-of-the-art in fabrication of aligned fibers via electrospinning techniques and the effects of these techniques on the mechanical and dielectric properties of electrospun fibers. Molecular orientation, system configuration to align fibers, and post-drawing treatment, like hot/cold drawing process, contribute to better specific strength and specific stiffness properties of nanofibers. The authors suggest that these improved, aligned nanofibers, when applied in composites, have better mechanical and dielectric properties for many structural and multifunctional applications, including advanced aerospace applications and energy storage devices. For these applications, most fiber alignment electrospinning research has focused on either mechanical property improvement or dielectric property improvement alone, but not both simultaneously. Relative to many other nanofiber formation techniques, the electrospinning technique exhibits superior nanofiber formation when considering cost and manufacturing complexity for many situations. Even though the dielectric property of pure nanofiber mat may not be of general interest, the analysis of the combined effect of mechanical and dielectric properties is relevant to the present analysis of improved and aligned nanofibers. A plethora of nanofibers, in particular, polyacrylonitrile (PAN) electrospun nanofibers, are discussed for their mechanical and dielectric properties. In addition, other types of electrospun nanofibers are explored for their mechanical and dielectric properties. An exploratory study by the author demonstrates the relationship between mechanical and dielectric properties for specimens obtained from a rotating mandrel horizontal setup.

Hierarchical aligned ZnO nanorods on surface of PVDF/Fe2O3 nanofibers by electrospinning in a magnetic field

The electrospinning was applied to fabricate aligned nanofibers in a magnetic field. Fe2O3 nanoparticles were added to PVDF/Zn(CHCOOH)2solution, and heat treatment of the nanofiber mats was made to produce PVDF/Fe2O3nanofibers containing ZnO nanoparticles. Hierarchical composites were obtained via a facile hydrothermal growth process, where radially oriented ZnO nanorods were found. The morphology of the as-synthesized samples were investigated by using the scanning electron micrograph (SEM).

Synthesis of Si-C-N aligned nanofibers with preeminent electromagnetic wave absorption in ultra-broad band

As is common in one-dimensional materials, SiC-based nanofibers own the high temperature resistance and well electromagnetic wave absorption with the absorbing mechanism of polarization loss. To overcome the narrow effective...