title: Enhanced Specificity and Drug Delivery in Tumors by cRGD-Anchoring Thermosensitive Liposomes.
abstract: OBJECTIVE
  To develop RGD-targeted thermosensitive liposomes with increased tumor retention, improving drug release efficiency upon mild hyperthermia (HT) in both tumor and angiogenic endothelial cells.
  
  
  METHODS
  Standard termosensitive liposomes (TSL) and TSL containing a cyclic Arg-Gly-Asp (cRGD) pentapeptide with the sequence Arg-Cys-D-Phe-Asp-Gly (RGDf[N-Met]C) were synthetized, loaded with Dox and characterized. Temperature- and time-dependent drug release profiles were assessed by fluorometry. Intracellular Dox delivery was studied by flow cytometry and confocal microscopy. Cytotoxic effect of TSL and RGD-TSL was studied on B16Bl6 melanoma, B16F10 melanoma and HUVEC. Intravital microscopy was performed on B16Bl6 tumors implanted in dorsal-skin fold window-bearing mice. Pharmacokinetic and biodistribution of Dox-TSL and Dox-RGD-TSL were followed in B16Bl6 tumor bearing mice upon normothermia or initial hyperthermia conditions.
  
  
  RESULTS
  DLS and cryo-TEM revealed particle homogeneity and size of around 85 nm. Doxorubicin loading efficiency was >95%as assessed by spectrofluorometry. Flow cytometry and confocal microscopy showed a specific uptake of RGD-TSL by melanoma and endothelial cells when compared to TSL and an increased doxorubicin delivery. High resolution intravital microscopy demonstrated specific accumulation of RGD-TSL to the tumor vasculature. Moreover, application of hyperthermia resulted in massive drug release from RGD-TSL. Biodistribution studies showed that initial hyperthermia increases Dox uptake in tumors from TSL and RGD-TSL.
  
  
  CONCLUSIONS
  RGD-TSL have potency to increase drug efficacy due to higher uptake by tumor and angiogenic endothelial cells in combination with heat-triggered drug release.
authors.affiliation: Laboratory Experimental Surgical Oncology, Section Surgical Oncology Department of Surgery, Erasmus MC Cancer Center, Rotterdam, The Netherlands. b.dicheva@erasmusmc.nl.|Laboratory of Experimental Surgical Oncology, Department of Surgical Oncology, Erasmus MC Cancer Institute, PO Box 2040, 3000, CA, Rotterdam, The Netherlands. b.dicheva@erasmusmc.nl.
authors.forename: Bilyana M
authors.initials: BM
authors.lastname: Dicheva
authors.affiliation: Laboratory Experimental Surgical Oncology, Section Surgical Oncology Department of Surgery, Erasmus MC Cancer Center, Rotterdam, The Netherlands.
authors.forename: Timo L M
authors.initials: TL
authors.lastname: ten Hagen
authors.affiliation: Laboratory Experimental Surgical Oncology, Section Surgical Oncology Department of Surgery, Erasmus MC Cancer Center, Rotterdam, The Netherlands.
authors.forename: Ann L B
authors.initials: AL
authors.lastname: Seynhaeve
authors.affiliation: Laboratory Experimental Surgical Oncology, Section Surgical Oncology Department of Surgery, Erasmus MC Cancer Center, Rotterdam, The Netherlands.|Department of Pharmaceutics, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohamadreza
authors.initials: M
authors.lastname: Amin
authors.affiliation: Laboratory Experimental Surgical Oncology, Section Surgical Oncology Department of Surgery, Erasmus MC Cancer Center, Rotterdam, The Netherlands.|Institut Gustave Roussy, Villejuif, France.
authors.forename: Alexander M M
authors.initials: AM
authors.lastname: Eggermont
authors.affiliation: Laboratory Experimental Surgical Oncology, Section Surgical Oncology Department of Surgery, Erasmus MC Cancer Center, Rotterdam, The Netherlands.
authors.forename: Gerben A
authors.initials: GA
authors.lastname: Koning
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use; D045744:Cell Line, Tumor; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004317:Doxorubicin / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008081:Liposomes / Q000737:chemistry*; D008545:Melanoma / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D010456:Peptides, Cyclic / Q000737:chemistry*; D013696:Temperature; D014018:Tissue Distribution
chemical_list: D000903:Antibiotics, Antineoplastic; D003692:Delayed-Action Preparations; D008081:Liposomes; D010456:Peptides, Cyclic; C507169:cyclic arginine-glycine-aspartic acid peptide; D004317:Doxorubicin
keywords: Doxorubicin; RGD - thermosensitive liposomes; drug delivery; hyperthermia