An Introduction to Electrospun Nanofibers for Tissue Engineering Heart Valves

摘要

In recent years, the application of natural/synthetic based nanofibers in different industries such as textile, environmental engineering, biomedical engineering, energy and electronics have been the subject of many researches. This is particularly due to their unique properties (particularly high surface-to-volume ratio that is approximately 1,000 times more than that of human hair). Electrospinning is a straightforward and promising technique used to fabricate ultrafine quality of continuous nanofibers within a diameter range of 20-1000 nm. As a customary setup for electrospinning, a high potential electrical field is applied to the emerging solution at the spinneret nozzle tip for transforming the jet into the nanofibers. Electrospinning can be employed in a laboratory as well as in industries when expanded. Obviously, the process/system parameters involved influence the structural and mechanical properties of electrospun nanofibers. The microstructure of nanofibers and subsequently the macro-properties of electrospun mats can be modified by varying the parameters involved in electrospinning process. The fabricated electrospun mats are interconnected, non-woven nanofibers deposited over the collector surface. High porosity, remarkable mechanical properties such as an elastic modulus within the MPa/GPa range and capacity to be formed into a variety of shapes are the other properties of electrospun nanofibers. Co-axial electrospinning is an advanced method of electrospinning where a dual nozzle spinneret is used for fabricating a core/shell structure of nanofibers. Any conductive polymer solution can be used as the shell for any other conductive polymer solution or nanoparticles depending on the application. This review of an electrospinning technique provides detailed information on the background of electrospinning, fundamental principles and theory, investigation on parameters involved in nanofibers' structural/ biological/mechanical characteristics, advantages of superb properties and biomedical applications of electrospun nanofibers, particularly in tissue engineering heart valves. In addition, the reasons for common instabilities, which result in the failure of Taylor cone formation and subsequently the failure of fiber production, are also explained.