title: Targeting of porous hybrid silica nanoparticles to cancer cells.
abstract: Mesoporous silica nanoparticles functionalized by surface hyperbranching polymerization of poly(ethylene imine), PEI, were further modified by introducing both fluorescent and targeting moieties, with the aim of specifically targeting cancer cells. Owing to the high abundance of folate receptors in many cancer cells as compared to normal cells, folic acid was used as the targeting ligand. The internalization of the particles in cell lines expressing different levels of folate receptors was studied. Flow cytometry was used to quantify the mean number of nanoparticles internalized per cell. Five times more particles were internalized by cancer cells expressing folate receptors as compared to the normal cells expressing low levels of the receptor. Not only the number of nanoparticles internalized per cell, but also the fraction of cells that had internalized nanoparticles was higher. The total number of particles internalized by the cancer cells was, therefore, about an order of magnitude higher than the total number of particles internalized by normal cells, a difference high enough to be of significant biological importance. In addition, the biospecifically tagged hybrid PEI-silica particles were shown to be noncytotoxic and able to specifically target folate receptor-expressing cancer cells also under coculture conditions.
authors.affiliation: Center for Functional Materials, Department of Physical Chemistry, Abo Akademi University, Porthansgatan 3-5, FI-2500 Turku, Finland.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Rosenholm
authors.forename: Annika
authors.initials: A
authors.lastname: Meinander
authors.forename: Emilia
authors.initials: E
authors.lastname: Peuhu
authors.forename: Rasmus
authors.initials: R
authors.lastname: Niemi
authors.forename: John E
authors.initials: JE
authors.lastname: Eriksson
authors.forename: Cecilia
authors.initials: C
authors.lastname: Sahlgren
authors.forename: Mika
authors.initials: M
authors.lastname: Lindén
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry; D018920:Coculture Techniques; D016503:Drug Delivery Systems; D005434:Flow Cytometry / Q000379:methods; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D016062:Porosity; D011956:Receptors, Cell Surface / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D011108:Polymers; D011956:Receptors, Cell Surface; D012822:Silicon Dioxide; D011094:Polyethyleneimine; D005492:Folic Acid