Fabrication and surface modification of melt-electrospun poly(D,L-lactic-co-glycolic acid) microfibers

Abstract

In this study, biodegradable poly(D,L-lactic-co-glycolic acid) (PLGA) fibers were prepared by a melt-electrospinning and treated with plasma in the presence of either oxygen or ammonia gas to modify the surface of the fibers. The effects of processing parameters on the melt-electrospinning of PLGA were examined in terms of fiber morphology and diameter. Among the processing parameters, the spinning temperature and mass flow rate had a significant effect on the average fiber diameter and its distribution. The water contact angle of melt-electrospun PLGA fibers decreased significantly from 123 A degrees to 55 A degrees (oxygen plasma treatment) or to 0 A degrees (ammonia plasma treatment) by plasma treatment for 180 sec, while their water content increased significantly from 2.4 % to 123 % (oxygen plasma treatment) or to 189 % (ammonia plasma treatment). Ammonia gas-plasma enhanced the surface hydrophilicity of PLGA fibers more effectively compared to oxygen gas-plasma. X-ray photoelectron spectroscopy analysis supported that the number of polar groups, such as hydroxyl and amino groups, on the surface of PLGA fibers increased after plasma treatment. Overall, the microfibrous PLGA scaffolds with appropriate surface hydrophilicity and fiber diameter could be fabricated by melt electrospinning and subsequent plasma treatment, without a significant deterioration of fiber structure and dimensional stability. This approach of controlling the surface properties and structures of fibers could be useful in the design and tailoring of novel scaffolds for tissue engineering.