Phage-display library biopanning and bioinformatic analysis yielded a high-affinity peptide to inflamed vascular endothelium both in vitro and in vivo

Vascular inflammation is considered the primary pathological condition occurring in many chronic diseases. To detect the inflamed endothelium via imaging analysis or guide the drug to target lesions is therefore important for early diagnosis and treatment of vascular inflammatory diseases. In this study, we obtained a novel peptide NTTTH through high throughout biopanning and bioinformatic analysis. In vitro studies indicated that NTTTH homologs could especially target inflamed vascular endothelial cells, as imaging quantitative analysis indicated that the mean of integrated optical density (MIOD) and mean of stained area (MSA) were significantly higher versus control (P < 0.05). In vivo studies showed that, after intravenous injection of enhanced green fluorescent protein (EGFP)-labeled NTTTH homologs into the lipopolysaccharide (LPS)-inflamed mice for 30 min, NTTTH homologs were distributed in highly vascularized and inflamed organs like liver and kidney. As a control, little fluorescence could be detected in mice injected with EGFP alone. Cryosection showed that NTTTH homologs especially targeted inflamed vasculatures but not normal ones. We did not detect fluorescence signal in either normal or inflamed mice which were injected with EGFP alone. The results suggested the role of NTTTH homologs in guiding the targeted binding of EGFP to inflamed vasculature and the potential usage for imaging detection and drug delivery. (C) 2013 Elsevier B.V. All rights reserved.