Year: 2015
Type: article
Abstract: The number of diabetics, obese individuals and other patients carrying other lifestyle diseases\nis increasing worldwide. At the same time the population is ageing. These patients all suffer\nfrom poor blood circulation, which often gives rise to non-healing, or chronic, wounds. Thus,\nthe number of chronic wounds is also increasing at a fast pace. Such wounds often carry\ninfection since the wound environment is favorable for bacteria. The wounds cause pain, odor\nand can lead to amputation or even death. Hence, the patients are treated with systemic and\ntopical antimicrobial substances, e.g. antibiotics. However, the overexposure and misuse of\nsuch drugs has created another issue worldwide: bacterial resistance. There are already some\ninfections that are difficult to treat due to the rapid development of bacterial resistance and\nfewer working drugs.\nOur work has focused on a release platform that can administer drugs only when a wound\nshows signs of infection. By sensing the type of infection at hand, the release system should\nbreak down and expose a suitable antimicrobial substance to the bacteria. Such a release\nsystem would not only combat the infection but also decrease the risk of bacterial resistance\nand other side effects on the patient, since it would be administered locally and only when it is\nneeded.\nTwo bacteria were chosen as targets, Staphylococcus aureus and Pseudomonas aeruginosa,\nwhich often are pathogenic in chronic wounds. Both bacteria exude very substrate specific\nproteases, i.e. V8 and Protease IV, respectively. Hence, nanofilms corresponding to each\nprotease were assembled via the layer-by-layer route. V8 readily degrades peptide bonds\ninvolving poly-L-glutamic acid (PLGA), which also was the main component in the release\nsystem against S. aureus, while Protease IV degrades bonds involving poly-L-lysine, which\nhence was used as component in the release system against P. aeruginosa. The nanofilms\nwere found not to be degraded by normal human enzymes; however, each bacterial protease\nruptured their respective film if they reached a concentration similar to the concentration\nfound in a chronic wound. Consequently, the drug was released or exposed only when in\ncontact with the bacterial enzymes. Such release systems could be used to fight infection\nwhile avoiding bacterial resistance and misuse of antimicrobials.\n
Author: Marina Craig
Language: English
Topic: Wound Healing and Treatments
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1701602413