Effect of molecular weight on mechanical properties of electrospun poly (lactic acid) fibers for meniscus tissue engineering scaffold

Abstract

Molecular weight (MW) is an important factor that affects mechanical properties of polymeric material. The positive relationship between molecular weight and mechanical properties of polymeric fibers can be ascribed to an increase in the length of the molecular chains. In this research, effect of Polylactic acid (PLA) molecular weight on morphological and mechanical properties of electrospun PLA were studied. PLA with two different molecular weights were used to prepare some samples by using electrospinning process at various concentrations (10%, 15% and 20% w/v). The condition for fabricating electrospun PLA was a 15 cm of collection distance and 15 kV of working voltage. Morphology of the electrospun PLA was studied by the field emission scanning electron microscope (FE-SEM). Mechanical properties including tensile strength, Young’s modulus and elongation at break were determined by using the universal testing machine. The obtained suitable sample with optimum mechanical properties will be used in further step for the meniscus tissue engineering scaffold. The result of the study reported, the 20% low molecular weight electrospun (PLAL-20%H) fibers has the highest tensile strength (2.83 ± 0.47 MPa) and Young’s modulus (160.67 ± 34.06 MPa) while 20% the high molecular weight electrospun (PLAH-20%) fibers has the highest elongation at break (25.87 ± 6.47%). In fact, the uniform and smooth surface fibers was observed in high relative humidity (RH) condition during electrospining process. In conclusion, higher mechanical properties of electrospun PLA nanofiber were obtained from a higher concentration.