Tuning Mechanical Properties of the Composite Nanofibers by Changing the Composition of the Polymer Solution

ABSTRACT: Composite nanofibers are suitable candidates for applications in biomedical engineering. The relationship and the balance between the structural-volumetric characteristics and the mechanical behavior of the nanofibrous composites have been proved but, in this study, we studied the pattern of such relationships between random and aligned nanofibrous composites made up of PLGA and fibrin. After evaluating the fibers' morphology and the mats' porosity, the relationship between these two features and the tensile strength of the mats was investigated. All mats exhibited relatively homogeneous fibers with higher fiber diameters for random fibers than the oriented ones (0.23 to 1.65 µm and 0.34 to 0.58 µm, respectively) and the diameter of the fibers decreased by fibrin percentage. The porosity proportions of the mats were in the range of 78.4% to 81.4% and random mats depicted higher porosity and interconnected pores. The mechanical features of the mats were compatible with natural tissues and the mechanical characteristics of the aligned mats were higher. In aligned mats, fibrin decreased the diameter of the fibers and the porosity proportion, limited the fiber’s thickness distribution, and increased the interconnectivity of the pores and all these factors led to lowering the tensile strength and the stiffness of the aligned mats. On the other hand, the porosity features of the random mats did not significantly change by fibrin, but fibrin lowered the diameter of the fibers and limited the fiber’s thickness distribution, and these two factors decreased the tensile strength and stiffness of the random mats