title: Intracellular trafficking and cellular uptake mechanism of PHBV nanoparticles for targeted delivery in epithelial cell lines.
abstract: BACKGROUND
  Nanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3).
  
  
  RESULTS
  As a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents.
  
  
  CONCLUSIONS
  Our results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.|Escuela de Bioquímica, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Peñaloza
authors.affiliation: Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Echaurren #183, 8370071, Santiago, Chile.
authors.forename: Valeria
authors.initials: V
authors.lastname: Márquez-Miranda
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.|Escuela de Bioquímica, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Cabaña-Brunod
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.|Escuela de Bioquímica, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Reyes-Ramírez
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.|Escuela de Bioquímica, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Felipe M
authors.initials: FM
authors.lastname: Llancalahuen
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.|Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Echaurren #183, 8370071, Santiago, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Vilos
authors.affiliation: Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Maldonado-Biermann
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Velásquez
authors.affiliation: Laboratorio de Genética y Patógenesis Bacteriana, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Fuentes
authors.affiliation: Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Echaurren #183, 8370071, Santiago, Chile.
authors.forename: Fernando D
authors.initials: FD
authors.lastname: González-Nilo
authors.affiliation: Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Maité
authors.initials: M
authors.lastname: Rodríguez-Díaz
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile. maria.otero@unab.cl.
authors.forename: Carolina
authors.initials: C
authors.lastname: Otero
mesh_terms: D001692:Biological Transport; D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000378:metabolism*; D016503:Drug Delivery Systems; D004705:Endocytosis; D006367:HeLa Cells; D006801:Humans; D053758:Nanoparticles / Q000378:metabolism* / Q000648:ultrastructure; D009369:Neoplasms / Q000188:drug therapy*; D011091:Polyesters / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D004337:Drug Carriers; D011091:Polyesters; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates