Antibacterial Activity on Orthopedic Clinical Isolates and Cytotoxicity of the Antimicrobial Peptide Dadapin-1

In orthopedic surgery, biomaterial-associated infections represent a complication of serious concern. Most promising strategies to prevent these infections currently rely on the use of anti-infective biomaterials. Desirably, in anti-infective biomaterials, the antibacterial properties should be achieved by doping, grafting, or coating the material surfaces with molecules that are alternative to conventional antibiotics and exhibit a potent and highly specific activity against bacteria, without altering the biocompatibility. Antimicrobial peptides (AMPs) are among the most interesting candidate molecules for this biomaterial functionalization. Here, the potential expressed by the recently discovered peptide Dadapin-1 was explored by assaying its MIC, MBIC and MBC on clinical strains of relevant bacterial species isolated from orthopedic infections and by assessing its cytotoxicity on the human osteoblast-like MG63 cells. When appropriately tested in diluted Mueller Hinton Broth II (MHB II), Dadapin-1 exhibited significant antibacterial properties. MIC values were in the range of 3.1-6.2 mu M for the gram-positive bacteria Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus warneri, and 12.4-24.9 mu M for the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Interestingly, the peptide was found non-cytotoxic, with an IC50 exceeding the highest concentration tested of 179 mu M. Overall, Dadapin-1 expresses considerable potential for future application in the production of anti-infective biomaterials.

Automated summary

In orthopedic surgery, preventing biomaterial-associated infections is a major concern. An effective strategy is to use anti-infective biomaterials that are coated, grafted, or doped with alternative molecules to conventional antibiotics. Antimicrobial peptides (AMPs) show promise as candidate molecules for this purpose. This study explored the potential of the peptide Dadapin-1, finding it to have significant antibacterial properties against relevant bacterial species while being non-cytotoxic to human cells. These findings suggest Dadapin-1 could be used in the production of anti-infective biomaterials.