Thermosensitive Sterically Stabilized Liposomes: Formulation and in Vitro Studies on Mechanism of Doxorubicin Release by Bovine Serum and Human Plasma
- 631 Downloads
Purpose. To formulate thermosensitive sterically stabilized liposomes and to study the effects of plasma and serum components in vitro.
Methods. The rate of release of encapsulated doxorubicin (Dox) from liposomes of various compositions was followed by fluorometric assay at 37°, 42° and 45°C, in buffer and also in both calf serum and human plasma up to 50% by volume.
Results. The optimal composition for the maximal differential release of doxorubicin between 37°C and 42°C in human plasma was a mixture of dipalmitoylphosphatidylcholine/hydrogenated soy phosphatidylcholine/cholesterol and distearoylphosphatidylethanolamine derivatized with polyethylene glycol at a molar ratio of 100:50:30:6. In experiments designed to study the mechanism causing increased permeability of liposomes in bovine serum, we found two different distinct release patterns: a slow linear rise of rate of Dox release for fluid liposomes and fast exponential rise reaching plateau within 5 minutes for solid phase (rigid) liposomes. This release of Dox from rigid but not fluid liposomes was inhibited by pre-heating serum at 55°C for 30 minutes or by addition of EDTA (but not EGTA) or antiserum to the C3 component of complement.
Conclusions. A formulation of sterically stabilized liposomes with the proper thermal sensitivity in human plasma has been obtained. In addition, the results suggest that complement may play an important role in the interaction of rigid but not fluid liposomes with bovine serum. Human plasma did not show this effect.
Unable to display preview. Download preview PDF.
- 1.I.H. Kedar and N. M. Bleehen. Experimental and clinical aspects of hyperthermia, applied to the treatment of cancer with special reference to the role of ultrasonic and microwave heating. Adv. Radiat. Biol. 6:229–266 (1976).Google Scholar
- 2.D. Papahadjopoulos, T.M. Allen, A. Gabizon, E. Mayhew, K. Matthay, S.K. Huang, K.D. Lee, M.C. Woodle, D.D. Lasic, C. Redemann and F.J. Martin. Sterically stabilized liposomes: Improvements in pharmacokinetics and antitumor therapeutic efficacy. Proc. Natl. Acad.Sci (USA) 88:11460–11464 (1991).Google Scholar
- 3.M.B. Yatvin, H. Muhlensiepen, W. Porschen, J.N. Weinstein, L.E. Feinendegen. Selective delivery of liposome-associated Cis-dichlorodiammineplatinum (II) by heat and its influence on tumor drug uptake and growth. Cancer Res 41:1602–1607 (1981).Google Scholar
- 4.S. Maekawa, K. Sugimachi, M. Kitamura. Selective treatment of metastatic lymph nodes with combination of local hyperthermia and temperature-sensitive liposomes containing bleomycin. Cancer Treat. Rep. 71:1053–1059 (1987).Google Scholar
- 5.J.N. Weinstein, R.L. Magin, M.B. Yatvin and D.S. Zaharko. Liposome and local hyperthermia: Selective delivery of methotrexate to heated tumors. Science 204:188–191 (1979).Google Scholar
- 6.K. Iga, Y. Ogawa and H. Toguchi. Heat induced drug release rate and maximal targeting index of thermosensitive liposome in tumor bearing mice. Pharmaceut. Res. 9:658–662 (1991).Google Scholar
- 7.K. Iga, N. Hamaguchi, Y. Igari, Y. Ogawa, H. Toguchi and T. Shimamoto. Increased tumor Cisplatin levels in heated tumors in mice after administration of thermosensitive, large unilamellar vesicles encapsulating Cisplatin. J. Pharm. Sci. 180:522–525 (1991).Google Scholar
- 8.J.L. Merlin. Encapsulation of Doxorubicin in thermosensitive small unilamellar vesicle liposomes. Eur. J. Cancer 27:1026–1030 (1991).Google Scholar
- 9.G. Gregoriadis. Fate of injected liposomes: observations on entrapped solute retention, vesicle clearance and tissue distribution in vivo. In G. Gregoriadis, (ed.), Liposomes as Drug Carriers, John Wiley & Sons Ltd., Chichester, 1988, pp. 3–18.Google Scholar
- 10.A. Chonn, P.R. Cullis, and D.V. Deviene. The role of surface charge in the activation of the classical and alternative pathways of complement by liposomes. J. Immunol. 146:4234–4241 (1991).Google Scholar
- 11.F.C. Szoka and D. Papahadjopoulos. Comparative properties and methods of preparation of lipid vesicles (liposomes). Ann. Rev. Biophys. Bioeng. 9:467–508 (1980).Google Scholar
- 12.G. Haran, R. Cohen, L.K. Bar, Y. Barenholz. Transmembrane ammonium sulfate gradients in liposomes produce efficient and stable entrapment of amphip. weak bases. Biochim. Biophys. Acta, 1151:201–215 (1993).Google Scholar
- 13.D. Papahadjopoulos, K. Jacobson, S. Nir and T. Isac. Phase transition in phospholipid vesicles: Fluorescence polarization and permeability measurements concerning the effect of temperature and cholesterol. Biochim. Biophys. Acta 311:330–348 (1973).Google Scholar
- 14.V. Yashar and Y. Barenholz. The interaction of Cholesterol and Cholest-4-en-3-one with dipalmitoylphosphatidylcholine. Comparison based on the use of three fluorophores. Biochim. Biophys. Acta. 985:271–278 (1989).Google Scholar
- 15.E.J. Luna and H.M. Mc Connell. Lateral phase separations in binary mixtures of phospholipids having different charges and different crystalline structures. Biochim. Biophys. Acta. 470:303–316 (1977).Google Scholar
- 16.E. Mayhew, Y. Rustum, F. Szoka and D. Papahadjopoulos. Role of Cholesterol in enhancing the antitumor activity of cytosine arabinoside entrapped in liposomes. Cancer Treat. Rep. 63:1923–1928 (1979).Google Scholar
- 17.S.K. Huang, P.R. Stauffer, K. Hong, J.W.H. Guo, T.L. Phillips, A. Huang, and D. Papahadjopoulos. Liposomes and hyperthermia in mice: increased tumor uptake and therapeutic efficacy of Doxorubicin in sterically stabilized liposomes. Cancer Res. 54:2186–2191 (1994).Google Scholar
- 18.H.M. Gaber, N.Z. Wu, K. Hong, S.K. Huang, M.W. Dewhirst, and D. Papahadjopoulos. Thermosensitive liposomes: extravasation and release of contents in tumor microvascular networks. Int. J. Rad. Onc. Biol. Phys. In Press (1995).Google Scholar
- 19.K. Funato, R. Yoda and H. Kiwada. Contribution of complement system on destabilization of liposomes composed of hydrogenated egg phosphatidylcholine in rat fresh plasma. Biochim. Biophys. Acta. 1103:198–204 (1992).Google Scholar
- 20.N. Okada, T. Yasuda, T. Tsumita, and H. Okada. Activation of the alternative complement pathway of guinea-pig by liposomes incorporated with trinitrophenylated phosphatidylethanolamine. Immunol. 45:115–124 (1982).Google Scholar
- 21.S. B. Field and J. W. Hand (Eds). An introduction to the practical aspects of clinical Hyperthermia. Taylor and Francis, Publ., New York, 1990.Google Scholar
- 22.H. I. Bicher, F. W. Hetzel, T. S. Sandhu, S. Frinak, P. Vaupel, M. D. O'Hara and T. O'Brien. Effects of hyperthermia on normal and tumor microenvironment. Radiology 137:523–531 (1980).Google Scholar
- 23.T.M. Allen, C. Hansen, F. Martin, C. Redemann. and A. Yau Young. Liposomes containing synthetic lipid derivatives of poly(ethyleneglycol) show prolonger circulation half-lives in vivo. Biochim. Biophys. Acta 1066:29–36 (1991).Google Scholar
- 24.A. A. Gabizon, A. Dagan, D. Goren, Y. Barenholz and Z. Fuks. Liposomes as in vivo carriers of adriamycin: reduced cardiac uptake and preserved antitumor activity in mice. Cancer Res. 42:4737–4739 (1982).Google Scholar
- 25.K. Maruyama, D. Unezaki, N. Takahashi and I. Motoharu. Enhanced delivery of doxorubicin to tumor by long-circulating thermosensitive liposomes and local hyperthermia. Biochim. Biophys. Acta. 1149:209–216 (1993).Google Scholar
- 26.S. Unezaki, K. Maruyama, N. Takahashi, M. Koyama, T. Yuda, A. Suginaka and M. Iwatsuru. Enhanced delivery and antitumor activity of Doxorubicin using long-circulating thermosensitive liposomes containing amphipathic polyethylene glycol in combination with local hyperthermia. Pharm. Res. 11,8:1180–1185, (1994).Google Scholar
- 27.G. Scherphof and H. Morselt. On the size dependent distintegration of small unilamellar phosphatidylcholine vesicles in rat plasma. Biochemistry 221:423–429 (1984).Google Scholar
- 28.D. Liu and L. Huang. Small, but not large, unilamellar liposomes composed of Dioleoylphosphatidylethanolamine and Oleic acid can be stabilized by human plasma. Biochemistry 28:7700–7707 (1989).Google Scholar
- 29.H. Harashima, K. Sakata, K. Funato and H. Kiwada. Enhanced hepatic uptake of liposomes through complement activation depending on the size of liposomes. Pharmaceut. Res. 11: 402–406 (1994).Google Scholar
- 30.E. Fattal, S. Nir, R.A. Parente, and F. C. Szoka, Jr. Poreforming peptides induce rapid phospholipid flip-flop in membranes. Biochemistry 33:6721–6731, (1994).Google Scholar