Disclosed is a composition comprising shortened poly-&bgr；-1&rarr；4-Nacetylglucosamine fibers, wherein the shortened fibers have been produced by irradiating poly-&bgr；-1&rarr；4-N-acetylglucosamine fibers with a dose of irradiation, and wherein (i) the length of greater than 50% of the shortened fibers is less than about 15 &mu；m in length or (ii) the average length of the shortened fibers is less than about 15 &mu；m in length.
