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Block copolymer micelles as drug carriers | 13:38 |
Block copolymer micelles are composed of polymer chains with sequences of hydrophilic and hydrophobic blocks. In a dilute aqueous solution, they form spherical or cylindrical nano-objects comprised of several chains with a hydrophobic core and extended hydrophilic corona. Lipophilic drugs can be dissolved in the core of these micelles, while the corona will assure solubility of this nano-container in aqueous media. In addition, if the corona is composed of a block which does not induce the immune reaction (for example PEO) the interior of the micelle will be invisible to the immune system. Such systems are extensively studied experimentally. The questions that can be answered within the SCMFT method include: the critical micellar concentration (CMC) of the aggregates, the region of stability of micelles, the maximal load of drug as a function of a chain architecture, the equilibrium sizes and size distributions of micelles loaded with and without drug. Finally, we can predict the release rate of the active component, modifying the method in line with the Dynamic Density Functional Theory (DDFT) using the local variations of the SCMF free energy as the thermodynamic force causing the material flow. We are constantly looking for practical applications of our theory.
The architecture of the primary sequence of the block copolymer can be altered in order to achieve desired properties. For example, this is the case in the so-called scorpion-like surfactants, where the hydrophobic block is constructed from two stiff units composing a fixed angle. Such a structure allows for more space inside the core of the micelle to carry a lipophilic drug, thus increasing the load of drug per micelle.
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Category: Fields of research |
Views: 3033 |
Added by: drug-delivery
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