Fabrication of drug-releasing textile materials

In ion complexes between drugs and ion-exchange fibers, the drugs act as the mobile counter ion. They can be released by ions in the body fluids, though this might disturb the homeostasis. Furthermore, in ex-vivo apphcations the amount of such ions will probably be too low to achieve sufficient drug release. Hence a co-solution of a salt, such as sodium chloride or sodium phosphate, is often used. The sodium ions will replace the drug ions and the latter will combine with the chloride or phosphate ions. 

The salt can be encompassed in a gel based on gelatin, agar, or polyvinyl alcohol, which is then brought into contact with the textile fiber loaded with the drug. The salt will diffuse through the gel and fiber, and thus release the drug. 

Wool and other animal fibers contain hydroxyl, amine, carboxylate, and thiol groups that can easily react with nanoparticles. Synthetic fibers usually have a limited number of reactive groups, while ceUulosic fibers have hydroxyl groups as the only reactives. To increase the possible particle-textile combinations, a bifunctional molecule can be used to link an amine-reactive particle with cellulose in order to attach reactive amine groups on the cellulose fibers. 

Eor particle fixation, the textile material is exposed to a solution, dispersion, or emulsion of the textile-reactive particles by conventional methods such as soaking, dipping, spraying, fluid flow, or padding, in which a catalyst may be present in the medium. The actual fixation takes place in the curing stage, which can proceed while the textile is still in contact with the particle solution, or preferably after the drying 

In the case of using a linker molecule, the textile material may first be treated with the linker and subsequently with the particle solution. The contact time can vary widely, from seconds to days, as can treatment temperatures and pressures. 

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