title: Transferrin receptor specific nanocarriers conjugated with functional 7peptide for oral drug delivery.
abstract: In an attempt to increase the interaction of a nanocarrier system with gastrointestinal epithelial cells, a transferrin receptor (TfR) specific 7peptide was conjugated to PEG-b-PCL copolymer and the functional nanocarriers were constructed and characterized. The endocytosis, intracellular trafficking and transcytosis of such nanocarriers loaded with coumarin 6 (7pep-M-C6) in a human colon carcinoma cell line (Caco-2) were investigated, followed by the in vivo intestine distribution study. The real-time imaging of live cell, three dimensional reconstruction of confocal image, quantitative colocalization analysis and other techniques were applied. First, the TfR expression was confirmed in Caco-2. Then, 7pep-M-C6 exhibited higher intracellular uptake compared with unmodified nanocarriers. In a live cell study, 7pep-M-C6 demonstrated faster uptake kinetics especially in the surface of cells. Together with a competition study using TfR antibody, it was proved that the increased cellular uptake was due to a receptor-mediated mechanism. Besides the unspecific endocytosis pathway, 7pep-M-C6 was found to enter the cells through a specific clathrin-mediated mechanism, related to the expression of TfR on Caco-2 cells. Possibly for this reason, 7pep-M-C6 tended to colocalize more with late endosomes and lysosomes than the control micelles. Also for the same mechanism, the increased transport of 7pep-M-C6 across Caco-2 monolayer was found, through a transcellular but not a paracellular pathway, while an increased in vivo intestinal distribution of 7pep-M-C6 was observed. In conclusion, the functional nanocarriers could specifically interact with gastrointestinal endothelial cells, increase their transport and alter their pathway as a result.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Du
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Fan
authors.forename: Nan
authors.initials: N
authors.lastname: Zheng
authors.forename: Bing
authors.initials: B
authors.lastname: He
authors.forename: Lan
authors.initials: L
authors.lastname: Yuan
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Xueqing
authors.initials: X
authors.lastname: Wang
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Wang
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003374:Coumarins / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D004705:Endocytosis; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000648:ultrastructure; D007783:Lactones / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D049329:Nanostructures / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011990:Receptors, Transferrin / Q000378:metabolism*; D013844:Thiazoles / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D003374:Coumarins; D007783:Lactones; D010455:Peptides; D011990:Receptors, Transferrin; D013844:Thiazoles; C517282:coumarin 6; C521904:poly(ethylene glycol)-block-poly(epsilon-caprolactone); D011092:Polyethylene Glycols