Purpose: In this study, the electrospinnability of poly(lactic-co-glycolic acid) (PLGA) solutions was investigated, with a focus on understanding the influence of molecular weight of PLGA, solvent type and solvent composition on the physical properties of electrospun nanofibers.
Method: Various solvents were tested to dissolve two PLGA grades (50 KDa-RG755, 100 KDa-RG750). The viscoelasticity, surface tension, and evaporation rate of the PLGA solutions were characterized prior to the electrospinning process. The resulting electrospun nanofibers were characterized with respect to the morphology and mechanical properties.
Results: Two pairs of solvent mixtures, i.e. dimethylformamide (DMF)-tetrahydrofuran (THF) and DMF-chloroform (CHL), were identified to provide a stable cone-jet. Within the polymer concentration range studied (10-30%, w/v), RG750 solutions could be electrospun into uniform fibers at 30% (w/v) or at 20% (w/v) when modifying the solvent composition. In comparison to DMF-THF solution, fibers had larger diameter, higher stiffness and tensile strength when electrospun from DMF-CHL solution.
Conclusion: The high molecular weight polymer could ensure sufficient intermolecular interaction to generate uniform fibers. The solvent could influence the morphology and mechanical properties of the electrospun fibers by altering the properties of PLGA solution, and drying rate of fibers in the electrospinning process.
Keywords: electrospinning; mechanical property; morphology; rheological property.