title: Dynamics of nanoparticle diffusion and uptake in three-dimensional cell cultures.
abstract: This study aims at elucidating the effect of three-dimensional (3D) extracellular matrix on cell behaviour and nanoparticle (NP) diffusion and its consequences on NP cellular uptake mechansims. For this purpose, human dermal fibroblasts (HDF) and human fibrosarcoma (HT1080) cell lines were grown within a 3D collagen gel and exposed to model polystyrene (PS) NPs of controlled size (44 and 100nm). Results indicate that, in 3D, cell morphology dramatically changes compared to standard 2D cultures and NP diffusion within the matrix is hampered by the interaction with the collagen fibres. As a consequence, NP cellular uptake, modeled with equations describing the stoichiometric exchange between NPs and cell membrane, is significantly slowed down in 3D and in the case of 100 nm NPs, in part due to the hampered diffusion of NPs in collagen gel compared to their transport in standard cell culture medium. Furthermore, our outcomes point at a significant contribution of the cytoskeleton assembly, in particular actin microfilaments, in governing the uptake of PS NPs in a 3D environment, and also that the macropinocytosis process is preserved and is mainly involved in the internalization of PS NPs in a 3D environment. However, depending on cell type and nanoparticle size, other endocytic pathways are also implicated when moving from 2D to 3D culture systems. This work highlights the importance of studying the nano-bio interaction in experimental models that resembles in vivo conditions in order to better predict the therapeutic efficacy of drug delivery systems.
authors.affiliation: Center for Advanced Biomaterial for Health Care (CABHC), Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci 53, Napoli, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Belli
authors.affiliation: Center for Advanced Biomaterial for Health Care (CABHC), Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci 53, Napoli, Italy; Centro di Ricerca Interdipartimentale sui Biomateriali (CRIB), Università di Napoli Federico II, Piazzale Tecchio 80, Napoli, Italy. Electronic address: daniela.guarnieri@iit.it.
authors.forename: Daniela
authors.initials: D
authors.lastname: Guarnieri
authors.affiliation: Dipartimento di Farmacia, Università di Napoli Federico II, Via Domenico Montesano 49, Napoli, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Biondi
authors.affiliation: Centro di Ricerca Interdipartimentale sui Biomateriali (CRIB), Università di Napoli Federico II, Piazzale Tecchio 80, Napoli, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Della Sala
authors.affiliation: Center for Advanced Biomaterial for Health Care (CABHC), Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci 53, Napoli, Italy; Centro di Ricerca Interdipartimentale sui Biomateriali (CRIB), Università di Napoli Federico II, Piazzale Tecchio 80, Napoli, Italy.
authors.forename: Paolo A
authors.initials: PA
authors.lastname: Netti
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D018929:Cell Culture Techniques; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D002470:Cell Survival / Q000187:drug effects; D003094:Collagen / Q000737:chemistry; D004058:Diffusion; D004705:Endocytosis / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005372:Filipin / Q000494:pharmacology; D005782:Gels; D006801:Humans; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry / Q000494:pharmacology*; D013395:Sucrose / Q000494:pharmacology
chemical_list: D005782:Gels; D011137:Polystyrenes; D013395:Sucrose; D005372:Filipin; D003094:Collagen; D015739:Nocodazole
keywords: 3D extracellular matrix; Cell morphology; Cytoskeleton assembly; Nanoparticles; Uptake kinetic; Uptake mechanism