Development of chitosan-tripolyphosphate fiber for biomedical application

Chitosan, a glycosaminoglycan, is the second most abundant naturally occurring polysaccharides. It has been extensively exploited in biomaterials research due to its easy tailorable structure and function. Chitosan fibers are being produced through wet-spinning route for different purposes. But, chitosan fibers produced in conventional alkaline bath generally suffers from quick dissolution in acidic media and high degradation rate in vivo. Crosslinking of the fibers with chemical agents is usually preferred to avoid that problem of instability. The crosslinking agents are highly toxic in nature and not suitable for biomedical use. Crosslinking of chitosan fibers with any non-toxic agent could make it better biocompatible and may find potential biomedical application. Present study focuses on production of chitosan-tripolyphosphate fibers through wetspinning technique. STPP was used as an in situ coagulant cum crosslinking agent for chitosan fibers. The fibers were produced by injecting homogeneous chitosan solution through a spinneret into sodium tripolyphosphate (STPP) coagulation bath. Viscosity of the chitosan solutions was measured for evaluation of flow behavior at different shear rate. FTIR analysis revealed presence of ionic cross-linking between tripolyphosphates (TPP) and chitosan molecules in chitosan-TPP fibers. Swelling behavior and water retention capacity of the chitosan-TPP fibers were also evaluated. Scanning electron micrographs showed fine chitosan fibers with diameters ~ 40 ¿m. These chitosan-TPP fibers may have potential biomedical applications due to their non-toxic in nature and enhanced stability.