title: Uptake and transport of B12-conjugated nanoparticles in airway epithelium.
abstract: Non-invasive delivery of biotherapeutics, as an attractive alternative to injections, could potentially be achieved through the mucosal surfaces, utilizing nanoscale therapeutic carriers. However, nanoparticles do not readily cross the mucosal barriers, with the epithelium presenting a major barrier to their translocation. The transcytotic pathway of vitamin B12 has previously been shown to 'ferry' B12-decorated nanoparticles across intestinal epithelial (Caco-2) cells. However, such studies have not been reported for the airway epithelium. Furthermore, the presence in the airways of the cell machinery responsible for transepithelial trafficking of B12 is not widely reported. Using a combination of molecular biology and immunostaining techniques, our work demonstrates that the bronchial cell line, Calu-3, expresses the B12-intrinsic factor receptor, the transcobalamin II receptor and the transcobalamin II carrier protein. Importantly, the work showed that sub-200 nm model nanoparticles chemically conjugated to B12 were internalised and transported across the Calu-3 cell layers, with B12 conjugation not only enhancing cell uptake and transepithelial transport, but also influencing intracellular trafficking. Our work therefore demonstrates that the B12 endocytotic apparatus is not only present in this airway model, but also transports ligand-conjugated nanoparticles across polarised epithelial cells, indicating potential for B12-mediated delivery of nanoscale carriers of biotherapeutics across the airways.
authors.affiliation: Division of Drug Delivery and Tissue Engineering, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Robyn
authors.initials: R
authors.lastname: Fowler
authors.affiliation: Division of Drug Delivery and Tissue Engineering, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Driton
authors.initials: D
authors.lastname: Vllasaliu
authors.affiliation: Division of Molecular and Cellular Science, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Franco H
authors.initials: FH
authors.lastname: Falcone
authors.affiliation: Division of Drug Delivery and Tissue Engineering, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Garnett
authors.affiliation: UCB Pharma, 208 Bath Road, Slough, Berkshire SL1 3WE, UK.
authors.forename: Bryan
authors.initials: B
authors.lastname: Smith
authors.affiliation: UCB Pharma, 208 Bath Road, Slough, Berkshire SL1 3WE, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Horsley
authors.affiliation: Division of Drug Delivery and Tissue Engineering, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Cameron
authors.initials: C
authors.lastname: Alexander
authors.affiliation: Division of Drug Delivery and Tissue Engineering, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK. Electronic address: Snjezana.Stolnik@nottingham.ac.uk.
authors.forename: Snow
authors.initials: S
authors.lastname: Stolnik
mesh_terms: D001692:Biological Transport; D051242:Caveolin 1 / Q000032:analysis; D002460:Cell Line; D002966:Clathrin / Q000032:analysis; D015870:Gene Expression; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000032:analysis / Q000235:genetics; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism*; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D051242:Caveolin 1; D002966:Clathrin; D011956:Receptors, Cell Surface; C029486:intrinsic factor-cobalamin receptor; C028176:transcobalamin receptor; D014805:Vitamin B 12
keywords: Airway epithelium; Calu-3 cells; Cubilin; Epithelial nanoparticle transport; Vitamin B(12)