Mechanical characterization of a melt-drawn Poly(L-lactide-co-ε-caprolactone) (PLC) for tissue engineering application
Goh, Wei Jian
Date of Issue2016-05-11
School of Mechanical and Aerospace Engineering
This report outlines the student’s project to investigate the mechanical properties of melt-drawn POLY(L-lactide-co--caprolactone) (PLC) of 90-10 composition used in tissue engineering. It is a type of semicrystalline co-polymer. The glass transition temperature of POLY(L-lactide-co--caprolactone) is measured at the range of 15 – 20 C, making this copolymer elastomeric at body temperature. Firstly, literature reviews have been done to analyze the mechanical properties of human esophagus. By comparing the mechanical properties of PLC scaffolds and human esophagus, we can highlight the differences and learnt how to apply it in tissue engineering. From fabrication to mechanical testing of PLC scaffolds, it allows us to understand the material structure and its behavior under different stresses and variables throughout the experiment. The variables such as rotational speed applied during the sample fabrication may affect the mechanical properties of the PLC scaffolds. For mechanical testing of PLC scaffolds, the fabricated samples are prepared into strips of 5 mm by 20 mm (n = 3) and they are sandwiched in between fine grade sand paper. After preparation, they will undergo uniaxial testing using INSTRON 5566 tensile testing machine. The mechanical tests include both pull to failure testing and pre-conditioning cyclic testing to find out maximum stress or strain that the material can withstand. After the mechanical testing, results on the mechanical properties of the PLC is obtained from the experiment and can be used to analyze the PLC scaffolds effectively. An experimental result summary for PLC samples fabricated under 150 revolutions/min (RPM) and 600 revolutions/min is listed below. For 150 RPM samples, mean ultimate tensile strength of 14.42 Mpa, mean yield strength of 12.45 Mpa and modulus of elasticity of 1.67 are obtained. For 600 RPM samples, mean ultimate tensile strength of 13.43 Mpa, mean yield strength of 11.35 Mpa and modulus of elasticity of 2.32 are obtained. On the other hand, for mechanical properties of porcine esophagi is given as mean ultimate tensile stress of 9.43 Mpa and modulus of elasticity of 2.71. As such, a comparison can be made between the mechanical properties of PLC scaffold and esophagus. Thus, this research focus on finding out the benefits of PLC and whether it can be applicable to esophageal tissue engineering. Finally, the results from the experiment can enable us to learn more about the mechanical properties of the PLC scaffolds and understand how it can be put to good use in tissue engineering, in this case, we are referring to human esophagus. The fabrication and mechanical testing of the PLC samples are also done concurrently to maintain the accuracy of the results.
Final Year Project (FYP)
Nanyang Technological University