Pharmaceutical Research

, Volume 25, Issue 11, pp 2567–2572 | Cite as

Surface Modification of Pharmaceutical Nanocarriers with Ascorbate Residues Improves their Tumor-Cell Association and Killing and the Cytotoxic Action of Encapsulated Paclitaxel In Vitro

  • Gerard G. M. D’Souza
  • Tao Wang
  • Karen Rockwell
  • Vladimir P. Torchilin
Research Paper



To evaluate the potential of ascorbate as a novel ligand in the preparation of pharmaceutical nanocarriers with enhanced tumor-cell specific binding and cytotoxicity.


Palmitoyl ascorbate was incorporated into liposomes at varying concentrations. A stable formulation was selected based on size and zeta potential measurements. A co-culture of cancer cells with GFP expressing non-cancer cells was used to determine the specificity of palmitoyl ascorbate liposome binding. Liposomes were fluorescently labeled to facilitate analysis by flow cytometry and fluorescence microscopy. The cytotoxic action of palmitoyl ascorbate liposomes against a variety of cell types was assayed using a standard metabolic assay. The cytotoxic effect of a low dose of paclitaxel incorporated in palmitoyl ascorbate liposomes on various cell lines was also determined.


Palmitoyl ascorbate liposomes associated preferentially with various cancer cells compared to non-cancer cells in a co-culture model. Palmitoyl ascorbate liposomes exhibited anti-cancer toxicity in numerous cancer cell lines. Furthermore, ascorbate liposomes enhanced the effectiveness of encapsulated paclitaxel compared to paclitaxel encapsulated in ‘plain’ liposomes.


Surface modification of liposomes with ascorbate residues represents a novel way to target and kill certain types of tumor cells and additionally can potentiate the effect of paclitaxel delivered by the liposomes.


ascorbate cancer liposomes nanocarriers targeting 



This research is based on a hypothesis originated and proposed by Anthony R. Manganaro. Funding was provided by Anthony R. Manganaro.


  1. 1.
    S. J. Padayatty et al. Vitamin C pharmacokinetics: implications for oral and intravenous use. Ann. Intern. Med. 140(7):533–537 (2004).PubMedGoogle Scholar
  2. 2.
    E. Cameron, and L. Pauling. Supplemental ascorbate in the supportive treatment of cancer: Prolongation of survival times in terminal human cancer. Proc. Natl. Acad. Sci. U. S. A. 73(10):3685–3689 (1976) doi: 10.1073/pnas.73.10.3685.PubMedCrossRefGoogle Scholar
  3. 3.
    E. T. Creagan et al. Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial. N. Engl. J. Med. 301(13):687–690 (1979).PubMedGoogle Scholar
  4. 4.
    C. G. Moertel et al. High-dose vitamin C versus placebo in the treatment of patients with advanced cancer who have had no prior chemotherapy. A randomized double-blind comparison. N. Engl. J. Med. 312(3):137–141 (1985).PubMedGoogle Scholar
  5. 5.
    Q. Chen et al. Pharmacologic ascorbic acid concentrations selectively kill cancer cells: action as a pro-drug to deliver hydrogen peroxide to tissues. Proc. Natl. Acad. Sci. U. S. A. 102(38):13604–13609 (2005) doi: 10.1073/pnas.0506390102.PubMedCrossRefGoogle Scholar
  6. 6.
    Q. Chen et al. Ascorbate in pharmacologic concentrations selectively generates ascorbate radical and hydrogen peroxide in extracellular fluid in vivo. Proc. Natl. Acad. Sci. U. S. A. 104(21):8749–8754 (2007) doi: 10.1073/pnas.0702854104.PubMedCrossRefGoogle Scholar
  7. 7.
    D. B. Agus, J. C. Vera, and D. W. Golde. Stromal cell oxidation: a mechanism by which tumors obtain vitamin C. Cancer Res. 59(18):4555–4558 (1999).PubMedGoogle Scholar
  8. 8.
    D. B. Agus et al. Vitamin C crosses the blood-brain barrier in the oxidized form through the glucose transporters. J. Clin. Invest. 100(11):2842–2848 (1997) doi: 10.1172/JCI119832.PubMedCrossRefGoogle Scholar
  9. 9.
    S. C. Rumsey et al. Dehydroascorbic acid transport by GLUT4 in Xenopus oocytes and isolated rat adipocytes. J. Biol. Chem. 275(36):28246–28253 (2000).PubMedGoogle Scholar
  10. 10.
    S. C. Rumsey et al. Glucose transporter isoforms GLUT1 and GLUT3 transport dehydroascorbic acid. J. Biol. Chem. 272(30):18982–1899 (1997) doi: 10.1074/jbc.272.30.18982.PubMedCrossRefGoogle Scholar
  11. 11.
    C. M. Kurbacher et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Lett. 103(2):183–189 (1996) doi: 10.1016/0304-3835(96)04212-7.PubMedCrossRefGoogle Scholar
  12. 12.
    C. D. Chiang et al. Ascorbic acid increases drug accumulation and reverses vincristine resistance of human non-small-cell lung-cancer cells. Biochem. J. 301(Pt 3):759–764 (1994).PubMedGoogle Scholar
  13. 13.
    A. M. Evens et al. Motexafin gadolinium generates reactive oxygen species and induces apoptosis in sensitive and highly resistant multiple myeloma cells. Blood. 105(3):1265–1273 (2005) doi: 10.1182/blood-2004-03-0964.PubMedCrossRefGoogle Scholar
  14. 14.
    N. J. Bahlis et al. Feasibility and correlates of arsenic trioxide combined with ascorbic acid-mediated depletion of intracellular glutathione for the treatment of relapsed/refractory multiple myeloma. Clin. Cancer Res. 8(12):3658–3668 (2002).PubMedGoogle Scholar
  15. 15.
    G. Rosenblat et al. Effect of ascorbic acid and its hydrophobic derivative palmitoyl ascorbate on the redox state of primary human fibroblasts. J. Med. Food. 4(2):107–115 (2001) doi: 10.1089/109662001300341761.PubMedCrossRefGoogle Scholar
  16. 16.
    S. Palma et al. Solubilization of hydrophobic drugs in octanoyl-6-O-ascorbic acid micellar dispersions. J. Pharm. Sci. 91(8):1810–1816 (2002) doi: 10.1002/jps.10180.PubMedCrossRefGoogle Scholar
  17. 17.
    D. Gopinath et al. Ascorbyl palmitate vesicles (Aspasomes): formation, characterization and applications. Int. J. Pharm. 271(1-2):95–113 (2004) doi: 10.1016/j.ijpharm.2003.10.032.PubMedCrossRefGoogle Scholar
  18. 18.
    F. Yuan et al. Microvascular permeability and interstitial penetration of sterically stabilized (stealth) liposomes in a human tumor xenograft. Cancer Res. 54(13):3352–3356 (1994).PubMedGoogle Scholar
  19. 19.
    H. Hashizume et al. Openings between defective endothelial cells explain tumor vessel leakiness. Am. J. Pathol. 156(4):1363–1380 (2000).PubMedGoogle Scholar
  20. 20.
    S. K. Hobbs et al. Regulation of transport pathways in tumor vessels: role of tumor type and microenvironment. Proc. Natl. Acad. Sci. U. S. A. 95(8):4607–4612 (1998) doi: 10.1073/pnas.95.8.4607.PubMedCrossRefGoogle Scholar
  21. 21.
    W. G. Kaelin Jr. The von Hippel-Lindau tumor suppressor gene and kidney cancer. Clin. Cancer Res. 10(18 Pt 2):6290S–625S (2004) doi: 10.1158/1078-0432.CCR-sup-040025.PubMedCrossRefGoogle Scholar
  22. 22.
    K. Block et al. NAD(P)H oxidases regulate HIF-2alpha protein expression. J. Biol. Chem. 282(11):8019–8026 (2007) doi: 10.1074/jbc.M611569200.PubMedCrossRefGoogle Scholar
  23. 23.
    M. Levine et al. Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proc. Natl. Acad. Sci. U. S. A. 93(8):3704–3709 (1996) doi: 10.1073/pnas.93.8.3704.PubMedCrossRefGoogle Scholar
  24. 24.
    M. V. Clement et al. The in vitro cytotoxicity of ascorbate depends on the culture medium used to perform the assay and involves hydrogen peroxide. Antioxid. Redox Signal. 3(1):157–163 (2001) doi: 10.1089/152308601750100687.PubMedCrossRefGoogle Scholar
  25. 25.
    K. K. Parsons et al. Ascorbic acid-independent synthesis of collagen in mice. Am. J. Physiol. Endocrinol. Metab. 290(6):E1131–E1139 (2006) doi: 10.1152/ajpendo.00339.2005.PubMedCrossRefGoogle Scholar
  26. 26.
    S. Telang et al. Depletion of ascorbic acid restricts angiogenesis and retards tumor growth in a mouse model. Neoplasia. 9(1):47–56 (2007) doi: 10.1593/neo.06664.PubMedCrossRefGoogle Scholar
  27. 27.
    R. C. Rose, and A. M. Bode. Biology of free radical scavengers: an evaluation of ascorbate. FASEB J. 7(12):1135–1142 (1993).PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Gerard G. M. D’Souza
    • 1
  • Tao Wang
    • 1
  • Karen Rockwell
    • 1
  • Vladimir P. Torchilin
    • 1
  1. 1.Department of Pharmaceutical Sciences and Center for Pharmaceutical Biotechnology and NanomedicineNortheastern UniversityBostonUSA

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