Polymer microcapsules

Steps 7-10 involved the selection of animal models, islet isolation and the testing of the polymer microcapsules as bioartificial organs. This has been discussed elsewhere [61,62]. 

Kreft O, Javier AM, Sukhorukov GB, Parak WJ (2007) Polymer microcapsules as mobile local pH-sensors. J Mater Chem 17 4471 1476... 

The destruction of hydrogen peroxide by catalase was also a research topic at Mitsubishi Gas Chemical Company [61]. Here, it was tried to encapsulate the enzyme in polymer microcapsules based on cross-linked polystyrene. The microencapsulated catalase showed improved thermostability and showed the same activity at 65 °C as the free catalase did at room temperature. A specific use of the immobilized enzyme was unfortunately not indicated. 

Microcapsules of synthetic polymer and cyclodextrin Three examples in the literature mention an association between synthetic polymer microcapsules and CyDs [12-14] as a means of encapsulating drugs complexed with CyDs. 

Yu J, Murthy VS, Rana RK, Wong MS (2006) Synthesis of nanoparticle-assembled tin ox-ide/polymer microcapsules. Chem Commun 10 1097-1099... 

Kentepozidou A, Kiparissides C. Production of water-containing polymer microcapsules by the complex emulsion/solvent evaporation technique. Effect of process variables on the microcapsule size distribution. Journal of Microencapsulation. November-December 1995 12(6) 627—638. PubMed PMID 8558385. 

For example, hydrophobic particles tend to be sequestered in the fiver [22]. Thus, adjustment of the size and wettability of the polymer microcapsules can have a great influence on their ultimate distribution in the body. 

Poly (DL-lactIc acid) biocompatible polymer, medicine Poly (DL-lactic acid) biocompatible polymer, microcapsules Poly (DL-lactic acid) biocompatible polymer, microspheres Poly (DL-lactic acid)... 

The protein-polymer microcapsules can be obtained by supercritical anti-solvent techniques [8]. Homogeneous protein-polymer mixtures were contacted with supercritical carbon dioxide in order to produce microspheres with diameter ranging from 1 to 5 pm and containing around 80% of protein. Production of PLA microparticles containing insulin, lysozyme, and chemotrypsin is claimed. SAS crystallization of a pharmaceutical (naproxen) and a biodegradable poly(L-lactic acid) was reported [8]. The results from SAS studies showed very small spherical particles... 

A. (2009) Oil-filled polymer microcapsules for ultrasound-mediated delivery of lipophilic drugs. / Controlled Release, 133, 109-118. 

Scanning electron microscopy (SEM) of microcapsules from which HD is extracted have been studied to understand the extent of encapsulation. One-hole, large-hole and half-moon morphologies imply that HD is not encapsulated completely by polymer, whereas a hollow morphology indicates complete encapsulation. Figure 5.8 shows SEM images of polymer microcapsules as a function of HD amount at lower monomer conversion (without DMAEMA). In the absence of DMAEMA, one-hole or... 

CdTe semiconductor nanocrystaline luminescent markers together with magnetite nanoparticles were firstly included into polymer microcapsules to control capsules remotely via magnetic field. Embedding magnetic nanoparticles in microcapsule shells gives an opportunity to control capsule transfer and shell permeability. For example, the authors of. used goldcobalt nanoparticles to "open" capsules remotely. 

D. Gorin, D. G. Shchukin, A. I. Mikhailov, K. Koehler, S. A. Sergeev, S. A. Portnov, I. V. Taranov, V. V. Kislov and G. B. Sukhorukov, Effect of microwave radiation on polymer microcapsules containing inorganic nanoparticles. Technical Physics Letters, 32(1), 70-72 (2006b). 

A. Shulkin, and H.D.H. Stover, Polymer microcapsules by interfacial polyaddition between styrene-maleic anhydride copolymers and amines, /. Membrane ScL, 209,421-432,2002. 

Overall, targeting strategies employing specific vector molecules are being actively pursued in many laboratories. Success with this approach has already been demonstrated in vivo with a variety of pharmaceutical carriers, including soluble polymers, microcapsules, microparticles, cells, cell ghosts, liposomes, and micelles, for a review see However, the actual usefulness of this approach for drug delivery in human trials remains to be seen. 

A variety of different formulations for controlled release polymers exist including microparticles, microcapsules and microspheres. Microparticles range in size from 1-200 pm, while particles with a diameter smaller than 1 pm are called nanoparticles. Microcapsules are microparticles which have the substance of interest enclosed in a shell of degradable polymer. Microcapsules however are characterized by a relatively fast release of large amounts of the enclosed substance. Microspheres (Figi 1), on the other hand, are monolithic in structure, Le. have the substance unifomdy distributed within the polymer layer. This distribution results in a more uniform release over longer periods of time. We selected such microspheies prepared from poly(lactide-glycolide) copolymers to develop our sensors. 

Zebli, B. Susha, A. S. Sukhorukov, G. B. Rogach, A. L. Parak, W. J., Magnetic Targeting and Cellular Uptake of Polymer Microcapsules Simultaneously Functionalized with Magnetic and Luminescent Nanocrystals. Langmuir, 2005, 21, 4262-4265. 

Figure 17.11 SEM image of multihollow polymer particles crosslinked with 50% EGDMA showing the (a) surface and (b) an internal image. (With kind permission from Springer Science + Business Media Colloid Polymer Science, Multihollow polymer microcapsules by water-in-oil-in-water emulsion polymerization Morphological study and entrapment characteristics, 281, 2, 2003, 157-163, J.-W. Kim, J.-Y. Ko, J.-B. Jun et al)...

Kim, J.-W. et al. (2003) MultihoUow polymer microcapsules by water-in-oil-in-water emulsion polymerization morphological study and entrapment characteristics. Colloid and Polymer Science, 281,157-163. 

Gaponik N, Radtchenko EL, Gerstenberger MR, Fedutik YA, Sukhorukov GB, Rogach AL (2003) Labeling of biocompatible polymer microcapsules with near-infrared emitting nanocrystals. Nano Lett 3 369-372... 

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