title: Tetrameric far-red fluorescent protein as a scaffold to assemble an octavalent peptide nanoprobe for enhanced tumor targeting and intracellular uptake in vivo.
abstract: Relatively weak tumor affinities and short retention time in vivo hinder the application of targeting peptides in tumor molecular imaging. Multivalent strategies based on various scaffolds have been utilized to improve the ability of peptide-receptor binding or extend the clearance time of peptide-based probes. Here, we use a tetrameric far-red fluorescent protein (tfRFP) as a scaffold to create a self-assembled octavalent peptide fluorescent nanoprobe (Octa-FNP) using a genetic engineering approach. The multiligand connecting, fluorophore labeling and nanostructure formation of Octa-FNP were performed in one step. In vitro studies showed Octa-FNP is a 10-nm fluorescent probe with excellent serum stability. Cellular uptake of Octa-FNP by human nasopharyngeal cancer 5-8F cells is 15-fold of tetravalent probe, ∼80-fold of monovalent probe and ∼600-fold of nulvalent tfRFP. In vivo enhanced tumor targeting and intracellular uptake of Octa-FNP were confirmed using optical imaging and Western blot analysis. It achieved extremely high contrast of Octa-FNP signal between tumor tissue and normal organs, especially seldom Octa-FNP detected in liver and spleen. Owing to easy preparation, precise structural and functional control, and multivalent effect, Octa-FNP provides a powerful tool for tumor optical molecular imaging and evaluating the targeting ability of numerous peptides in vivo.
authors.affiliation: Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
authors.forename: Haiming
authors.initials: H
authors.lastname: Luo
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Honglin
authors.initials: H
authors.lastname: Jin
authors.forename: Chuan
authors.initials: C
authors.lastname: Huang
authors.forename: Jianwei
authors.initials: J
authors.lastname: Fu
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Gong
authors.forename: Shaoqun
authors.initials: S
authors.lastname: Zeng
authors.forename: Qingming
authors.initials: Q
authors.lastname: Luo
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents; D045744:Cell Line, Tumor; D016503:Drug Delivery Systems; D005818:Genetic Engineering / Q000379:methods; D006801:Humans; D049408:Luminescent Agents / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics*; D008164:Luminescent Proteins / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D008958:Models, Molecular; D049329:Nanostructures; D009374:Neoplasms, Experimental / Q000473:pathology; D011487:Protein Conformation; D000097573:Red Fluorescent Protein
chemical_list: D000970:Antineoplastic Agents; D049408:Luminescent Agents; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein