title: Biodegradable nanoparticles sequentially decorated with Polyethyleneimine and Hyaluronan for the targeted delivery of docetaxel to airway cancer cells.
abstract: BACKGROUND
  Novel polymeric nanoparticles (NPs) specifically designed for delivering chemotherapeutics in the body and aimed at improving treatment activity and selectivity, cover a very relevant area in the field of nanomedicine. Here, we describe how to build a polymer shell of Hyaluronan (HA) and Polyethyleneimine (PEI) on biodegradable NPs of poly(lactic-co-glycolic) acid (PLGA) through electrostatic interactions and to achieve NPs with unique features of sustained delivery of a docetaxel (DTX) drug cargo as well as improved intracellular uptake.
  
  
  RESULTS
  A stable PEI or HA/PEI shell could be obtained by careful selection of layering conditions. NPs with exquisite stability in salt and protein-rich media, with size and surface charge matching biological requirements for intravenous injection and endowed with sustained DTX release could be obtained. Cytotoxicity, uptake and activity of both PLGA/PEI/HA and PLGA/PEI NPs were evaluated in CD44(+) (A549) and CD44(-) (Calu-3) lung cancer cells. In fact, PEI-coated NPs can be formed after degradation/dissociation of the surface HA because of the excess hyaluronidases overexpressed in tumour interstitium. There was no statistically significant cytotoxic effect of PLGA/PEI/HA and PLGA/PEI NPs in both cell lines, thus suggesting that introduction of PEI in NP shell was not hampered by its intrinsic toxicity. Intracellular trafficking of NPs fluorescently labeled with Rhodamine (RHO) (RHO-PLGA/PEI/HA and RHO-PLGA/PEI NPs) demonstrated an increased time-dependent uptake only for RHO-PLGA/PEI/HA NPs in A549 cells as compared to Calu-3 cells. As expected, RHO-PLGA/PEI NP uptake in A549 cells was comparable to that observed in Calu-3 cells. RHO-PLGA/PEI/HA NPs internalized into A549 cells showed a preferential perinuclear localization. Cytotoxicity data in A549 cells suggested that DTX delivered through PLGA/PEI/HA NPs exerted a more potent antiproliferative activity than free DTX. Furthermore, DTX-PLGA/PEI NPs, as hypothetical result of hyaluronidase-mediated degradation in tumor interstitium, were still able to improve the cytotoxic activity of free DTX.
  
  
  CONCLUSIONS
  Taken together, results lead us to hypothesize that biodegradable NPs coated with a PEI/HA shell represent a very promising system to treat CD44 overexpressing lung cancer. In principle, this novel nanocarrier can be extended to different single drugs and drug combinations taking advantage of the shell and core properties.
authors.affiliation: Laboratory of Drug Delivery, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. sara.maiolino@unina.it.
authors.forename: Sara
authors.initials: S
authors.lastname: Maiolino
authors.affiliation: Laboratory of Biochemistry, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. annapina.russo@unina.it.
authors.forename: Annapina
authors.initials: A
authors.lastname: Russo
authors.affiliation: Laboratory of Biochemistry, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. valentina.pagliara@unina.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Pagliara
authors.affiliation: Laboratory of Drug Delivery, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. claudia.conte@unina.it.
authors.forename: Claudia
authors.initials: C
authors.lastname: Conte
authors.affiliation: Laboratory of Drug Delivery, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. ungaro@unina.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ungaro
authors.affiliation: Laboratory of Biochemistry, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. giulia.russo@unina.it.
authors.forename: Giulia
authors.initials: G
authors.lastname: Russo
authors.affiliation: Laboratory of Drug Delivery, Department of Pharmacy, University of Napoli Federico II, Via Domenico Montesano 49, Napoli, 80131, Italy. quaglia@unina.it.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Quaglia
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D002460:Cell Line / Q000187:drug effects; D000077143:Docetaxel; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D057145:Nanoshells / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D043823:Taxoids / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D001672:Biocompatible Materials; C497483:CD44 protein, human; D005456:Fluorescent Dyes; D018960:Hyaluronan Receptors; D043823:Taxoids; D000077143:Docetaxel; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011094:Polyethyleneimine; D006820:Hyaluronic Acid