Nanocapsules, controlled release

One particular example of controlled release is sustained release. In this form the desired material is continuously released over a period of time at a constant rate. Two timely publications (3)(4) cover the general area of controlled release, which can also include the controlled release of agricultural materials and biological materials, far example, pheromones. In using the term microencapsulation in this article, the author intends to refer to capsules in the size range of 1 micron to 1000 microns. Capsules below 1 micron in size are frequently referred to as nanocapsules and they are made by one or more very specialized methods (5). The term capsule refers to macro objects in the order of 1 millimeter or larger. This term of capsule is frequently used in the delivery of pharmaceuticals. 

Prego, C., D. Torres, et al. (2006). Chitosan-PEG nanocapsules as new carriers for oral peptide delivery. Effect of chitosan pegylation degree. J Control Release 111(3) 299-308. 

Allard E, Passirani C, Garcion E, Pigeon P, Vessieres A, Jaouen G, Benoit JP (2008) Lipid nanocapsules loaded with an organometallic tamoxifen derivative as a novel drug-carrier system for experimental malignant gliomas. J Control Release 130 146-153... 

Toub, N., Angiari, C., Eboue, D., Fattal, E., Tenu, J. P., Le Doan, T., and Couvreur, P. (2005), Cellular fate of oligonucleotides when delivered by nanocapsules of poly(isobu tylcyanoacrylate),/. Controlled Release, 106(1-2), 209-213. 

Flillaireau, FI., Doan, T. L., Appel, M., and Couvreur, P. (2006), Flybrid polymer nanocapsules enhance in vitro delivery of azidothymidine-triphosphate to macrophages, J. Controlled Release, 116, 346-352. 

Nanocapsules Prepared by Interfacial Polymerization of Microemulsions, Proceedings of the 27th International Symposium on Controlled Release of Bioactive Materials of the Controlled Release Society, Inc., Paris, France, July 9-13, 2000 Abstract 6138. 

The use of microlatices for biological applications is also very attractive. Let us recall that conventional latices prepared from emulsion polymerization are already used for such purposes, for example, in immunoassays, as adsorbents for proteins, for immobilization of enzymes and antibodies, and for controlled release in drug delivery [165]. The latex particle size is in the range 0.1-10 /im. Stable microlatices in the nanosize range (20-30 nm) may be preferred, and some procedures based on inverse microemulsion polymerization have been proposed for the preparation of nanocapsules [4,166-169]. 

Lboutoimne, H., Charlet, JT., Ploton, C., Flason, F., and Pirot, E., Sustained ex vivo skin antiseptic activity of chlorhexidine in polyfepsilon-caprolactone) nanocapsule encapsulated form and as a digluconate, J. Control Release, 82 (2 3), 319-334, 2002. 

Damge, C., Michel, C., Aprahamian, M., Couvreur, P., and Devissaguet, J. P., 1990, Nanocapsules as carriers for oral peptide delivery, J. Controlled Release 13 233-239. 

Rosenbauer EM, Wagner M, Musyanovych A, Landfester K. Controlled release from polyurethane nanocapsules via pH-, UV-hght- or temperature-induced stimuh. Macromolecules 2010 43 5083-93. 

T. Nassar, A. Rom, A. Nyska, and S. Benita, Novel double coated nanocapsules for intestinal delivery and enhanced oral bioavailabihty of tacroKmus, a Pgp substrate drug, J. Control. Release, 133 (1), 7784,2009. 

Lee, S. H., Choi, S. H., Kim, S. H. and Park,T. G. (2008).Thermally sensitive cationic polymer nanocapsules for specific cytosolic delivery and efficient gene silencing of siRNA Swelling induced physical disruption of endosome by cold shock. Journal of Controlled Release, 125,25-32. 

Scheme 37 Encapsulation and controlled release from hypertranched core-shell nanocapsules.

Sukhomkov GB, Antipov AA, Voigt A, Donath E, Mohwald H. pH-Controlled macromolecule encapsulation in and release from polyelectrol3de multilayer nanocapsules. Macromol Rapid Commun 2001 22 44-46. 

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