Development of wet-spun alginate fibers for wound dressing applications

Abstract

Smart alginatebased wound dressings were successfully developed using the wet spinning process. In order to improve the mechanical properties and include the ability to promote tissue reconstruction of neat alginate fiber, chitin whisker, a nanofibrilla chitin, was incorporated in the alginate wet-spun fibers. Incorporation of low amount of chitin whiskers in the nanocompoite fibers improved the mechanical properties as well as accelerated the biodegradation process of the fibers in the presence of lysozyme. Antimicrobial property was introduced to alginate fibers by coating/incorporating the fibers with silver particles/chitosan whiskers, respectively. Good distribution of silver particles was observed at a low amount of the silvercoated alginate fiber, resulting in the enhancement of the mechanical properties of the fibers. The embedded chitosan whiskers lead the fibers to increase in the tensile strength but lowering the elongation at break. Both of the fibers show antibacterial efficacy against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. Lastly, a novel method of using chitosan in the form of an emulsion was proposed in order to overcome the major problem associated with the production of alginate/chitosan hybridized fibers by wet spinning which is the formation of gels due to ionic interactions of the oppositely-charged molecules of alginate and chitosan when these two polymers are directly mixed. By this method, chitosan can be mixed in alginate fiber up to 10% w/w. The alginate/chitosan hybridized fibers showed spotty features of the chitosan-citrate complex micelles on the surface and the inside of the hybridized fibers. Preliminary studies demonstrated that the obtained chitosanspotted alginate fibers showed great promises as carriers for drug delivery.