Collagen targeted self-anchoring antimicrobial molecular agents

The intrinsic characteristics of collagen, when combined with its natural abundance in the tissues and its easy exposure due to any fissure of epithelium during a wound or an injury, makes it a common site for bacterial colonization. Within dense collagen fibrils, such as those in dentin, bound pathogens are partially shielded from antibiotic penetration. With the increasing prevalence of antibiotic resistance, microbial infections remain a persistent global health concern. In this study, we engineered a collagen targeted self-anchoring antimicrobial peptide as a novel therapeutic agent and tested its multifunctional activities on a collagen platform. Our peptide design incorporated an antimicrobial peptide (AMP) with another peptide designed for collagen-binding properties through a spacer domain. The novel collagen targeted AMP (COLTAMP) peptide was computationally evaluated for its potential to simultaneously exhibit both desired functions, collagen-binding and antibacterial activity. The predicted secondary structure of COLTAMP was confirmed using Fourier-transform infrared and Raman spectroscopies as complementary vibrational techniques. The interactions of the targeted AMP with collagen fibrils were characterized using atomic force microscopy, providing insights into the effects of the peptide on the organization of fibrils. The antimicrobial activity of the targeted AMP was tested using a zone of inhibition assay against a model pathogen, Streptococcus mutans, which thrives in the oral cavity and colonizes distant tissues once it enters the bloodstream. Confirming the antimicrobial activity of COLTAMP, we next explored its mechanism of action using a scanning electron microscopy (SEM). SEM imaging confirmed bacterial cell wall disruption following the delivery of COLTAMP, leading to pronounced effects on bacterial membrane integrity. The proposed self-anchoring targeted multifunctional peptide offers spatially distributed antimicrobial peptides across collagen fibrils. Multifunctional targeted peptide agents that selectively anchor bioactive domains directly to damaged collagen offer potential treatment strategies for infections involving diverse injury sites.