Liposomes sterically stabilised

Adamina M, et al. Encapsulation into sterically stabilised liposomes enhances the immunogenicity of melanoma-associated Melan-A/MART-1 epitopes. Br J Cancer 2004 90 263. 

However, the degree of accumulation of liposomes in tumour tissue depends on their blood circulation time. In order to maximise the accumulation of liposomes, and thus boron, in the tumour, liposomes with long survival time in systemic circulation, should be employed. The liposomal circulation time may be dramatically increased by attachment of long flexible polyethylene glycol (PEG) chains to a proportion of the lipids in the liposomal membrane. Such sterically stabilised liposomes have been shown to circulate for several days, up to a week, without detection by the immune system. 

In order to fulfil the above requirements we have developed a concept that comprises sterically stabilised liposomes with double targeting (SLT-particles).8 Specific targeting is achieved by providing the sterically stabilised liposomes with ligands directed towards receptors that are overexpressed on the surface of the tumour cells. Furthermore, by choosing ligands that are directed towards receptors that mediate... 

Vaage, J., Donovan, D., Loftus, T., Abra, R., Working, P, Huang, A. Chemoprevention and therapy of mouse mammary carcinomas with doxorubicin encapsulated in sterically stabilised liposomes. Cancer 1994, 73, 2366-2371. 

Allen, T. M., Stuart, D. D. Liposomal pharmacokinetics — classical, sterically-stabilised, cationic hposomes and immunoliposomes. In Liposomes rational design (Janoff, A. S., Ed.), Marcel Dekker, Inc. New York, 2005, pp. 63-87. 

K. Kostarelos, T. F. Tadros, P. F. Luckham, Physical conjugation of (tri-) block copolymers to liposomes toward the construction of sterically stabilised vesicle systems, Langmuir, 1999, 15, 369-376. 

Kostarelos, K., Tadros, Th.F. and Luckham, P.F., Physical Conjugation of (tri-) Block Copolymers to Liposomes Toward the Construction of Sterically Stabilised Vesicle Systems , Langmuir 15, 369 - 376 (1999). 

This potential force occurs in microstructured fluids like microemulsions, in cubic phases, in vesicle suspensions and in lamellar phases, anywhere where an elastic or fluid boundary exists. Real spontaneous fluctuations in curvature exist, and in liposomes they can be visualised in video-enhtuiced microscopy [59]. Such membrane fluctuations have been invoked as a mechanism to account for the existence of oil- or water-swollen lamellar phases. Depending on the natural mean curvature of the monolayers boimding an oil region - set by a mixture of surfactant and alcohol at zero -these swollen periodic phases can have oil regions up to 5000A thick With large fluctuations the monolayers are supposed to be stabilised by steric hindrance. Such fluctuations and consequent steric hindrance play some role in these systems and in a complete theory of microemulsion formation. 

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