Polymers as wound dressings

An ideal wound dressing would be protective, proteolytic, and capable of relieving 

The skin provides a number of protective functions. The stratum corneum acts as a barrier that prevents invasive infection, and sebum secreted by sebaceous glands has an antibacterial action. The burn wound is vulnerable to bacterial colonization and invasive bacterial contamination and sepsis. As the burn depth increases the potential reservoir for bacterial invasion increases before viable tissue and host defenses are reached. Burns dressing should have either an antibacterial barrier function or a bactericidal/bacteriastatic function or ideally both. 

The dressing should also protect the regenerating epidermis from further mechanical injury. 

Apart from the most superficial injuries, the wound is going to result in a layer of dead tissue. The natural process of removing this tissue involves proteolysis and phagocytosis. The deeper the wound the more tissue has to be removed and the longer it will take for healing to occur. The ideal dressing would either support or augment the natural autolytic process or, even better, have an intrinsic enzymatic action. 

Apart from the selective promotion of specific cell behavior, the ideal wound dressing would also provide an environment which would be more conducive to heahng. In this respect, the healing wound performs better in a moist healing environment but not in a macerated heahng environment. As such, the dressing should have the physical ability to deal with the exudates produced by the wound but at the same time not allow the wound to dry out and the tissues to desiccate. 

8 Bioadhesivity of water-soluble polymers 8.4.9 Polymers as wound dressings 

Adhesion between a surface of a hydrophilic polymer, or a surface to which a hydrophilic polymer has been grafted or adsorbed, and a biological surface arises from interactions between the polymer chains and the macromolecules on the mucosal surface. From Fig. 8.23(a) it is clear that to achieve maximum adhesion there should be maximum interaction between the polymer chains of the bioadhesive (A) and the mucus (B). The charge on the molecules will be important, and for two anionic polymers maximum interaction will occur when they are not charged. Penetration and association must be balanced. Table 8.5 shows the adhesive performance of a 

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