Antibiotics enzymic modification

Fig. 5.1 Schematic representation of possible modifications for antimicrobial surfaces (left), tissue modulative surfaces (right) and multifunctional surfaces (middle). Antimicrobial surfaces can be achieved by the release and or by the surface display of antimicrobial substances, such as AMPS, antibiotics, enzymes, QSIs and antifouling polymers. A specific tissue response can be induced by the presentation of adhesive biomolecules, hydrogels scaffolds or micro-roughening, for example. Combining both of these approaches leads to multifunctional surfaces which discourage bacterial adhesion, or kill bacteria, while stimulating tissue cells to adhere, differentiate or express specific genes.

Over the past few years there have been an increasing number of reports of diseases that are becoming resistant to previously effective drug treatments. This resistance is often due to the presence of enzymes that bring about chemical modification of the drug to an inactive form, e.g. /S-lactamase enzymes deactivate (6-lactam antibiotics by their conversion to penicillanic acid. 

Resistance to a range of antibiotics is of increasing concern in clinical practice since the genes are often carried on transmissible plasmids. There are different types of mechanism that confer resistance, inclnding enzymatic covalent modification of the antibiotic, effective efflnx systems, and indnction of a cellnlar enzyme that is resistant to the antibiotic. Examples of these are used as illustration. 

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