Simulation-Based Development of a Nanoscale, Electro-spun, Biomimetic PCL/SF TM Implant

Tympanic membrane (TM) implants must fulfil a complex property profile in order to improve the quality of life of patients. These include acousto-mechanical vibration properties comparable to human TM, slow degradation rate, hydrophilicity and good biocompatibility. Human TM consists mainly of radial and circulating collagen fibers. Electro-spun membranes have a high potential for biomimetic replication of these structures. Furthermore, the nanofibers produced in this way morphologically resemble the natural extracellular molecules of TM: collagen and elastin. In addition, the acousto-mechanical properties of the membranes are determined by their complex, process-related microstructure. The aim of this work is development of a three-dimensional biomimetic TM implant based on polycaprolactone and silk fibroin by electrospinning. The influence of spinning solution viscosity, fiber diameter and orientation as well as porosity will be investigated. A numerical calculation of the effective stiffness of the materials is realized by the application of a homogenization process. Furthermore, a finite element model (FEM) is developed to simulate experimental tests of the sound transfer function with a laser Doppler vibrometer (LDV). Thus, the relationship between the microstructure of the nanofibers and the macroscale acousto-mechanical behavior of the implants can be identified by a parametric study. With the results obtained, real TM implants with a customized nanofiber structure produced, which are expected to have a sound transfer function comparable to human TM. Experiments on these TM implants will be performed and compared with the results of the FEM simulation in order to gain a broad understanding of the acousto-mechanical behavior.

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Artikel online veröffentlicht:
10. Juni 2020