Optimization of amphiphile-based colloidal carriers

Yechezkel Barenholz Some amphiphiles tend to self-aggregate; in others, aggregation to defined structures can be induced.¹ This, together with our ability to control the composition, type, shape, and size of the amphiphilebased assembly, I-3 makes these molecules excellent candidates to form suitable carriers for a broad spectrum of agents including water-soluble, amphipathic, and hydrophobic molecules of low, medium, and high molecular mass.3-5 These amphiphile-based assemblies include micelles and mixed micelles of various aggregation numbers and shapes, I-3,6 micelle-like assemblies,? liposomes of various types,3-5,8 emulsions, and microemulsions 10 The enormous built-in versatility due to large differences in the properties of each of the different assemblies - and the ability to control the physicochemical properties of each assembly by its composition and method of preparation - make them suitable to fit controlled-release and passive and active targeting of molecules associated with the assembly in a broad spectrum of applications, such as medicaI,3,4,8 cosmetic, II agricultural, ecological, food, and other industrial applications.3.6.8When using the same agent with various types of amphiphile-based carrier it becomes clear that the exact type of the colloidal assembly has a major impact on the performance of the agent associated with the assembly.12.13 To a large extent, the ability to form a suitable assembly regarding efficiency and stability of agent-loading, and the ability of the assembly to affect the performance of the agent, is dependent on the physicochemical properties of the agent and its mode of interaction with the molecules forming the carrier.