Antimicrobial and pro-angiogenic properties of soluble and nanoparticle-immobilized LL37 peptides

Antimicrobial peptides (AMPs), such as LL37 peptides, may be immobilized on the surface of medical devices to render them with antimicrobial and angiogenic properties. However, little is known about LL37 properties after immobilization. Here, we have studied the antimicrobial and pro-angiogenic activity of soluble and immobilized LL37 peptides (conjugated to gold nanoparticles). Both soluble and immobilized LL37 peptides have potent antimicrobial activity against Gram-positive and Gram-negative bacteria in the presence of 10% human serum (HS). However, the immobilized LL37 peptides showed less cytotoxicity to endothelial cells (ECs) at a concentration that was able to kill bacteria. Interestingly, although both soluble and immobilized LL37 peptides showed pro-angiogenic activities in Matrigel and chorioallantoic membrane (CAM) assays, they induce different signalling pathways in ECs. The results described here highlight the importance of investigating the properties of immobilized AMPs that might act as a new entity.

Automated summary

Both soluble and immobilized forms of LL37 peptides exhibit potent antimicrobial activity against bacteria, with the immobilized form showing lower cytotoxicity to endothelial cells at effective concentrations. Additionally, both forms have pro-angiogenic activities, but elicit different signaling pathways in endothelial cells.