Cellulose Fibres Funcionalised by Chitosan: Characterization and Application

Abstract

Fibrous (textile) materials, such as used in the medical field or health services can be divided into two basic groups, according to whether they are used 1) inside organic tissues (internal/implantable): vascular grafts, meshes, stents, tendons and ligament implants, surgical threads, etc.) or 2) on their surface (external/non-implantable): gauzes, bandages, surgical covers, nappies, tampons, etc. The use of natural cellulose fibers, such as cotton and flax, goes back in medical applications to ancient times and still today, in some medical applications, cellulose fibrous materials represent materials that can not be exchanged with any other. In the more recent past new procedures and technologies enabled the production of various chemical cellulose fibers such as viscose, modal and lyocell, which are cleaner and even more hygroscopic than cotton, and as such highly applicable within hygiene and medical fields. The great potential of cellulose fibers lies in their molecular structure, which offers excellent possibilities as a matrix for the design of bioactive, biocompatible, and intelligent materials. Over the last twenty years the increase in the number of microbially caused diseases and hospital infections has led to intensive research into new materials and procedures, which would assure permanent bioactive effects together with complete safety for the people (Chung et al. 1998, Liu et al. 2000, Lee et al. 1999). Fungi, as well as gram positive and gram negative bacteria are commonly found in textile materials, especially in bedclothes. Many of these microorganisms are pathogens or potential pathogens and quite often related to nosocomial infections (Takai et al. 2002). Fibrous materials used in the medical and hygiene fields are usually in contact with extremely contaminated environments. Escherichia Coli and Penicillium Crysogenum very often cause diseases, as well as the disintegration and foul smell of fibrous materials (Chang et al. 1996). Therefore, the most important biomedical characteristics of a fibrous material for external use are its’ antimicrobial properties. In textiles these are usually achieved by treatments with silvers salts, quaternary ammonium chloride, metals, aromatic, halogen compouns, etc. (Kenawy et al. 2007, Takai et al. 2002). Antimicrobial agents act either as growth inhibitors (bacterioor fungi-static) or they kill the microorganisms (bio-cidal). Almost all antimicrobial agents used in convetional textile treatments are biocidal, as they damage the cell wall or the membrane permeability, denature proteins, inhibit enzyme activity or lipid synthesis, which are all essential for cell survival (Gao et. al. 2008). The most important issue regarding biocides used on commercial textiles is the potential induction of bacterial resistance to these substances, which could also