Design and characterization of polymeric water-born nanostructures

Giuseppe Battaglia
Biomaterials & Tissue Engineering Group, Department of Engineering Materials, University of Sheffield, The Kroto Research Institute, Sheffield, United Kingdom. Research overview.

Today, the ability of biological membranes to form functional and dynamic structures with tuneable size that can vary from a few nanometers (vesicles) up to meters (neurons) has been mimicked by synthetic amphiphiles. New advances in polymeric chemistry and physics have recently allowed the design of a new class of amphiphilic membranes (1) based on amphiphilic block copolymers. These "super" amphiphiles have molecular weight much higher than the biological amphiphiles and therefore they generate highly entangled membranes providing the final structure with improved mechanical properties. This unique structure also has the intrinsic advantage that once it is formed the kinetics of destabilization can be very slow and consequently the lifetime of the supra-molecular structures they assemble is much longer than their biological analogues. Polymeric membranes form assemblies that have remarkable similarities with biological analogues , such as vesicles (1, 2), tubular myelins (3), and tissue-like structures (4). These membrane-enclosed structures have the unique ability to encapsulate hydrophilic compounds within their enclosed aqueous core, hydrophobic compounds within their membranes, and amphiphilic compounds aligned on the hydrophilic-hydrophobic interface. Furthermore, the wholly synthetic nature of such copolymers allows the application of different compositions and functionalities over a limitless range of molecular weights and consequently of membrane thicknesses. Herein, we present the different routes to control the architecture based on amphiphilic polymeric membranes. Furthermore, how these structures can be of asset for biomedical applications including gene delivery (5).

References
  1. D. E. Discher, A. Eisenberg, Science 297, 967-73 (2002).
  2. G. Battaglia, A. J. Ryan, J. Am. Chem. Soc. 127, 8757-8764 (2005).
  3. G. Battaglia, A. J. Ryan, Angew. Chem. Int. Edit. 45, 2052-2056 (2006).
  4. G. Battaglia, A. J. Ryan, Nature Mat. 4, 869-876 (2005).
  5. H. Lomas, I. Canton, S. MacNeil, J. Du, S. P. Armes, A. J. Ryan, A. L. Lewis, G. Battaglia, Adv. Mater. 2007, in the press.

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