Antibacterial materials for wound care applications utilizing antimicrobial peptides
Licentiate thesis, 2021
A wound bed is a haven for opportunistic pathogens and regardless of if it is caused by trauma or a surgical incision, bacteria that finds their way into a wound need to be dealt with in order to prevent an infection. Two approaches have been investigated in this thesis, with wound management as the application in mind. In the first approach, soft hydrogels were made out of the block copolymer Pluronic F-127 diacrylate. The polymer self-assembled into lyotropic liquid crystals which in turn were cross-linked in place. To these hydrogels, the antimicrobial peptide RRPRPRPRPWWWW-NH2 was covalently attached. This resulted in a non-toxic material consisting of 90 wt% water with an antibacterial surface active against the clinically relevant strains of bacteria S. aureus, S. epidermidis, and P. aeruginosa. It also showed good antibacterial effect against the antibiotic resistant strains MRSA and MDR-E. coli. In addition, this method increased the stability of the peptides against proteolytic degradation in serum.
The second approach focused on the development of particles using the same material foundation as the first approach. Particles were chosen in order to increase the antibacterial potential as well as obtaining a material suitable for applications where a liquid formulation is desired. The produced particles had a high antibacterial effect both in solution as well as in a slurry. For the slurry, the bacterial load of S. aureus in an agar plate model was reduced by 99.99%. Cryogenic electron microscopy experiments indicated that the mechanism of action for the AMP-modified particles indeed was due to interaction with the bacterial cell wall/membrane.
lyotropic liquid crystals
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Saba Atefyekta, Edvin Blomstrand, Anand K. Rajasekharan, Sara Svensson, Margarita Trobos, Jaan Hong, Thomas J. Webster, Peter Thomsen, and Martin Andersson, Antimicrobial Peptide Functionalized Mesoporous Hydrogels
Edvin Blomstrand, Anand K. Rajasekharan, Saba Atefyekta, and Martin Andersson, Cross-Linked Lyotropic Liquid Crystal Particles Modified with Antimicrobial Peptides for Antibacterial Applications
Chalmers Materials Analysis Laboratory
Areas of Advance
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