Bacterial resistance to antimicrobial agents, especially antibiotics, recently gained worldwide resonance, as more and more authorities start recognizing “superbugs” as a major problem for the future of healthcare. Known drugs are progressively losing efficacy due to excessive use or misuse and the risk of regression to pre-antibiotic death-by-infection rates seems a close reality. This threat demands strong multidisciplinary efforts by the scientific community toward the development of new antimicrobial technologies. Together with optimal functional and biological properties, novel medical devices and tissue engineering scaffolds should also provide an inhibitory effect against bacteria, preferably avoiding the use of conventional antibiotics. In this doctoral thesis, the research has focused on enhancing the antibacterial properties of biodegradable and bioresorbable polyesters (BBPEs), one of the most important classes of polymers for biomedical applications in orthopedics, tissue engineering and drug delivery among others. First, it is demonstrated how this class of materials lacks intrinsic pH-dependent antibacterial activity, a phenomenon that was hinted as a possible consequence of their hydrolytic degradation, albeit not confirmed by previous literature reports. Well-established optical density measurements and agar diffusion assays were performed, confirming that plain bioresorbable polyesters are not active against bacteria. In order to overcome this disadvantage of BBPEs, a novel antibiotic-free antibacterial material based on therapeutic ions-chelating chitosan was prepared and characterized. Chitosan is known to be an ideal ion-carrying polymer thanks to its chelating ability. The complexation of chitosan with several biologically relevant ions (e.g. zinc, cerium, calcium and copper) was investigated and demonstrated by combined analysis with Fourier-transform infrared and energy dispersive X-ray spectroscopies. Among these ions, copper was selected in this project. It acts as a quick inhibitor of ...


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    Title :

    An investigation on antibiotic-free antibacterial materials combining bioresorbable polyesters, chitosan and therapeutic ions ; Eine Untersuchung zu antibiotikafreien, antibakteriellen Materialien, die bioresorbierbare Polyester, Chitosan und therapeutische Ionen enthalten


    Contributors:

    Publication date :

    2019-01-01


    Type of media :

    Theses


    Type of material :

    Electronic Resource


    Language :

    English


    Keywords :

    Classification :

    DDC:    629




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