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  1. Atomic force microscope
  2. Atomic nanoscope
  3. Atom probe
  4. Ballistic conduction
  5. Bingel reaction
  6. Biomimetic
  7. Bio-nano generator
  8. Bionanotechnology
  9. Break junction
  10. Brownian motor
  11. Bulk micromachining
  12. Cantilever
  13. Carbon nanotube
  14. Carbyne
  15. CeNTech
  16. Chemical Compound Microarray
  17. Cluster
  18. Colloid
  19. Comb drive
  20. Computronium
  21. Coulomb blockade
  22. Diamondoids
  23. Dielectrophoresis
  24. Dip Pen Nanolithography
  25. DNA machine
  26. Ecophagy
  27. Electrochemical scanning tunneling microscope
  28. Electron beam lithography
  29. Electrospinning
  30. Engines of Creation
  31. Exponential assembly
  32. Femtotechnology
  33. Fermi point
  34. Fluctuation dissipation theorem
  35. Fluorescence interference contrast microscopy
  36. Fullerene
  37. Fungimol
  38. Gas cluster ion beam
  39. Grey goo
  40. Hacking Matter
  41. History of nanotechnology
  42. Hydrogen microsensor
  43. Inorganic nanotube
  44. Ion-beam sculpting
  45. Kelvin probe force microscope
  46. Lab-on-a-chip
  47. Langmuir-Blodgett film
  48. LifeChips
  49. List of nanoengineering topics
  50. List of nanotechnology applications
  51. List of nanotechnology topics
  52. Lotus effect
  53. Magnetic force microscope
  54. Magnetic resonance force microscopy
  55. Mechanochemistry
  56. Mechanosynthesis
  57. MEMS thermal actuator
  58. Mesotechnology
  59. Micro Contact Printing
  60. Microelectromechanical systems
  61. Microfluidics
  62. Micromachinery
  63. Molecular assembler
  64. Molecular engineering
  65. Molecular logic gate
  66. Molecular manufacturing
  67. Molecular motors
  68. Molecular recognition
  69. Molecule
  70. Nano-abacus
  71. Nanoart
  72. Nanobiotechnology
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  78. Nanocrystal solar cell
  79. Nanoelectrochemistry
  80. Nanoelectrode
  81. Nanoelectromechanical systems
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  83. Nano-emissive display
  84. Nanoengineering
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  115. Nanotube
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  117. Nanowire
  118. National Nanotechnology Initiative
  119. Neowater
  120. Niemeyer-Dolan technique
  121. Ormosil
  122. Photolithography
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  125. Quantum dot
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  128. Quantum solvent
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  131. Richard Feynman
  132. Royal Society's nanotech report
  133. Scanning gate microscopy
  134. Scanning probe lithography
  135. Scanning probe microscopy
  136. Scanning tunneling microscope
  137. Scanning voltage microscopy
  138. Self-assembled monolayer
  139. Self-assembly
  140. Self reconfigurable
  141. Self-Reconfiguring Modular Robotics
  142. Self-replication
  143. Smart dust
  144. Smart material
  145. Soft lithography
  146. Spent nuclear fuel
  147. Spin polarized scanning tunneling microscopy
  148. Stone Wales defect
  149. Supramolecular assembly
  150. Supramolecular chemistry
  151. Supramolecular electronics
  152. Surface micromachining
  153. Surface plasmon resonance
  154. Synthetic molecular motors
  155. Synthetic setae
  156. Tapping AFM
  157. There's Plenty of Room at the Bottom
  158. Transfersome
  159. Utility fog

 



NANOTECHNOLOGY
This article is from:
http://en.wikipedia.org/wiki/Transfersome

All text is available under the terms of the GNU Free Documentation License: http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License 

Transfersome

From Wikipedia, the free encyclopedia

 

Transfersome is a term registered as a trademark by the German company IDEA AG, and used by them to refer to their proprietary drug delivery technology. Active components of living cells - the cellular machinery - tend to have names ending in "some", hence the obviously derived name for a sub-cellular transfer system. A Transfersome is an artificial vesicle designed to be like a cell vesicle, and used to deliver drugs or genetic material into a cell. Its bounding membrane is more flexible than that of a liposome, allowing it to deform and pass through openings in a barrier, such as the skin, whose diameters are much smaller than the average vesicle size.

A Transfersome is an at least bi-component, most often vesicular, aggregate. The main functional characteristic of the aggregate is the extreme flexibility and permeability of its bilayer-like membrane coating. Its basis is the interdependency of local membrane shape and composition, which makes the bilayer self-regulating and self-optimising. The bilayer is thus capable of stress adaptation, via local and reversible bilayer component demixing. All this makes a Transfersome into a device suitable for non-invasive and targeted drug delivery, for example across intact skin.

Another beneficial consequence of high bilayer flexibility is the increased Transfersome affinity to bind and retain water. Ultradeformable Transfersome vesicles put in a dry environment therefore seek to find water richer region. This forces Transfersome vesicles applied on open skin to penetrate the skin barrier in a search for adequate hydration. The resulting vesicle migration is a consequence of continuous bilayer adaptation and deformation, but must not compromise unacceptably either the vesicle integrity or the protective skin barrier properties in real-life applications.

A basic Transfersome is composed of one natural amphiphat (such as phosphatidylcholine) that tends to self-aggregate into vesicles. The latter are then supplemented by at least one bilayer softener (e.g. a biocompatible surfactant). The vesicle-like Transfersome thus normally possesses an aqueous core surrounded by a complex, very fluid and adaptable lipid bilayer. In its basic organization broadly similar to a simple lipid vesicle (a so-called liposome), a Transfersome differs from the latter by its more flexible and permeable, "softened" bilayer membrane. A Transfersome vesicle can consequently change shape readily and easily by adjusting relative concentration of its two components in the bilayer to the local stress experienced by the complex bilayer. This can be observed indirectly by studying stress- or deformation-dependent vesicle bilayer elasticity or permeability. In a single experiment, the same goal can be achieved by determining the pressure dependency of Transfersome suspension-flux through a nano-porous filter (with the pores considerably smaller than the average vesicle size). The rate of resulting transport must grow with driving force (head pressure) non-linearly (often sigmoidally) until maximum flow is reached. For an ideal Transfersome, experiencing no friction in pores, the maximum flow is equivalent to the flux of the suspending liquid measured with a similar trans-filter pressure, and the minimum pressure required to attain good transport is a measure of bilayer flexibility. The observed functional dependency of suspension flux versus pressure can therefore be used to derive bilayer elasticity and flexibility, as well as permeability, based on theoretical description of the underlying enforced transport, viewed as an activated transport process.

References

  • G. Gompper, D.M. Kroll (October 1995). "Driven transport of fluid vesicles through narrow pores". Physical Review E 52 (4): 4198–4208. DOI:10.1103/PhysRevE.52.4198.
  • G. Cevc, A. Schätzlein, H. Richardsen (2002-08-19). "Ultradeformable Lipid Vesicles can Penetrate the Skin and other Semi-Permeable Barriers Intact. Evidence from Double Label CLSM Experiments and Direct Size Measurements". Biochim. Biophys. Acta 1564: 21–30. PMID 12100992.
  • G. Cevc, A. Schätzlein, H. Richardsen, U. Vierl (2003). "Overcoming semi-permeable barriers, such as the skin, with ultradeformable mixed lipid vesicles, Transfersomes, liposomes or mixed lipid micelles". Langmuir 19 (26): 10753–10763. DOI:10.1021/la026585n.
  • G. Cevc (2004). "Lipid vesicles and other colloids as drug carriers on the skin". Advanced Drug Delivery Reviews 56 (5): 675–711. PMID 15019752.

Further reading

  • Science. IDEA AG. — IDEA's own detailed explanation of what Transfersomes are and what they do.
  • What is the difference between liposomes and Transfersomes?. Scientific FAQ. IDEA AG.
  • Medical trial that started in 2005
Retrieved from "http://en.wikipedia.org/wiki/Transfersome"