title: Folate-targeted multifunctional amino acid-chitosan nanoparticles for improved cancer therapy.
abstract: OBJECTIVE
  Tumor targeting nanomaterials have potential for improving the efficiency of anti-tumoral therapeutics. However, the evaluation of their biological performance remains highly challenging. In this study we describe the synthesis of multifunctional nanoparticles decorated with folic acid-PEG and dual amino acid-modified chitosan (CM-PFA) complexed with DNA and their evaluation in organotypic 2D co-cultures of cancer-normal cells and also on 3D multicellular tumor spheroids models.
  
  
  METHODS
  The physicochemical characterization of CM-PFA multifunctional carriers was performed by FTIR, (1)H NMR and DLS. 2D co-culture models were established by using a 1:2 cancer-to-normal cell ratio. 3D organotypic tumor spheroids were assembled using micromolding technology for high throughput screening. Nanoparticle efficiency was evaluated by flow cytometry and confocal microscopy.
  
  
  RESULTS
  The CM-PFA nanocarriers (126-176 nm) showed hemocompatibility and were internalized by target cells, achieving a 3.7 fold increase in gene expression. In vivo-mimicking 2D co-cultures confirmed a real affinity towards cancer cells and a negligible uptake in normal cells. The targeted nanoparticles penetrated into 3D spheroids to a higher extent than non-targeted nanocarriers. Also, CM-PFA-mediated delivery of p53 tumor suppressor promoted a decrease in tumor-spheroids volume.
  
  
  CONCLUSIONS
  These findings corroborate the improved efficiency of this delivery system and demonstrate its potential for application in cancer therapy.
authors.affiliation: CICS-UBI - Health Sciences Research Centre, Universidade da Beira Interior, Avenida Infante D. Henrique, 6200-506, Covilhã, Portugal.
authors.forename: Vítor M
authors.initials: VM
authors.lastname: Gaspar
authors.forename: Elisabete C
authors.initials: EC
authors.lastname: Costa
authors.forename: João A
authors.initials: JA
authors.lastname: Queiroz
authors.forename: Chantal
authors.initials: C
authors.lastname: Pichon
authors.forename: Fani
authors.initials: F
authors.lastname: Sousa
authors.forename: Ilídio J
authors.initials: IJ
authors.lastname: Correia
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage / Q000737:chemistry; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry; D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry; D018920:Coculture Techniques; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods*; D005492:Folic Acid / Q000008:administration & dosage* / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D009369:Neoplasms
chemical_list: D000596:Amino Acids; D000970:Antineoplastic Agents; D004337:Drug Carriers; D048271:Chitosan; D005492:Folic Acid