Biofilm formation microbial degradation

All release systems that liberate an immobilized biocide into the surroundings will exhaust rather quickly. Furthermore, the constant release is an environmental issue and supports the building of biocide-resistance in microbial strains. If a release system is the only possible option, then it would be desirable to release the biocide on demand, e.g., in cases of infection or the start of biofilm formation. This can be achieved by either degrading or swelling the matrix with an infection-specific enzyme or metabolite, or by cleaving the linker between biocide and surface with a biochemical factor. 

Another way to keep microbial cells off surfaces is to create materials that constantly renew their surface, e.g., by being degraded. This so-called self-polishing does not keep microbes away effectively because the degradation process and the formation of a biofilm have different time scales. The latter takes merely hours, whereas the first should be in the range of days to months to provide a useful protection. In practice, such self-polishing systems only work in combination with released biocides and are discussed in Sect. 6.1 in greater detail. 

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