Use of Cellulose as Implant Material

Microbial cellulose derived from Acetobacter xylinum by fermentation process has been established to be a remarkably versatile biomaterial and can be used in wide variety of applied scientific endeavours, especially for medical devices. Due to its ultra-fine network architecture, high degree of crystallinity, hydrophilicity and moldability, microbial cellulose is a natural candidate for numerous medical and tissue-engineered apphcations. The use of direct nanomechanical measurement determined that these fibers are very strong, and when used in combination with other biocompatible materials, produce nanocomposites particularly suitable for use in human and veterinary 

Recently, it was found that microbial cellulose can be a good matrix for obtaining different types of calcium carbonate crystals with improved biocompatibility. In a recent study, calcium chloride (CaCy and sodimn carbonate (Na COj) have been used as starting reactants to promote caldiun carbonate deposition on microbial 

Microbial cellulose is an interesting material for biomedical applications. Materials intended as vascular grafts must satisfy many important features such as blood compatibility, cell interactions and mechanical properties. Microbial cellulose has xmique properties that make it an exciting candidate as a cardiovascular graft material strength. 

Several studies have shown that microbial cellulose can be molded into tubular form with diameter 6 mm. Klemm et al. [101] prepared a microbial cellulose tube having 1 mm diameter and 5 mm length with a wall thickness of 0.7 mm. The tensile strength of the material was foxmd to be comparable to that of normal blood vessels (800 mN) and is employed as blood vessel to replace part of the carotid artery. Alter four weeks, the microbial cellulose/carotid artery complex was covered with connective tissue. The in-vivo bicompatibility tests show that microbial cellulose can be used as a replacement blood vessel. Recently, Brown et al [102] have prepared small tubes of microbial cellulose-fibrin composites treated with glutaraldehyde in order to crosslink the polymers and allow a better match of the mechanical properties with those of native small-diameter blood vessels. 

The potential use of microbial cellulose-based composites for the production of heart valve replacements is currently under study. Milton et al [104] and Mohammadi et al [105] prepared biocompatible microbial cellulose-poly(vinyl alcohol) nanocomposite for the production of heart valve leaflets. The nanocomposite prepared by Millon and 

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