Polycyanoacrylates

As has been mentioned earlier, polycyanoacrylates possess a relatively low ceiling temperature, because the polymer will thermally revert back to monomer by an... 

Preparation of nanoparticles can be by a variety of different ways. The most important and frequently used is emulsion polymerization others include interfacial polymerization, solvent evaporation, and desolvation of natural proteins. The materials used to prepare nanoparticles are also numerous, but most commonly they are polymers such as poly-alklcyanoacrylate, polymethylmethacrylate, poly-butylcyanoacrylate, or are albumin or gelatin. Distribution patterns of the particles in the body can vary depending on their size, composition, and surface charge [83-85]. In particular, nanoparticles of polycyanoacrylate have been found to accumulate in certain tumors [86,87]. 

Polycyanoacrylates, Department of Polymer Science, University of Southern Mississippi. http //www.psrc.usm.edu/macrog/pca.htm... 

Couvreur P, Kante B, Roland M, Guiot P, Bauduin P, Speiser P (1979) Polycyanoacrylate nanocapsules as potential lysosomotropic carriers preparation, morphological and sorptive properties. J Pharm Pharmacol 31 331-332. 

Peracchia MT, Fattal E, Desmaele D, Besnard M, Noel JP, Gomis JM, Appel M, d Angelo J, Couvreur P (1999) Stealth PEGylated polycyanoacrylate nanoparticles for intravenous administration and splenic targeting. J Control Release 60 121-128. 

Calvo, P., et al. 2001. Long-circulating PEGylated polycyanoacrylate nanoparticles as new drug... 

Polycyanoacrylate - DermabondR product consisting of 2-ocyl-cyanocrylate plasticized and stabilized for antimicrobial growth. 

Kreuter, J., U. Muller, et al. (1989). Quantitative and microaudiographic study on mouse intestinal distribution of polycyanoacrylate nanoparticles. Int J Pharm 55 39-45. 

Calvo P, Gouridn B, Chacun H, Desmaele D, D Angelo J, Noel J, Georgin D, Fattal E, Andreux J, Couvreur P (2001) Long-circulating PEGylated polycyanoacrylate nanoparticles as new drug canier for brain delivery. Pharm Res 18 1157—1166. 

Calvo P, Gouiidn B, Villanoya H, Eclancher F, Giannavola C, Klein C, Andreux JP, Couvreur P (2002) Quantification and localization of PEGylated polycyanoacrylate nanopaificles in brain and spinal cord dui ing experimental allergic encephalomyelitis in tire rat. Eui JNeurosci 15 1317-1326. 

Kreuter, J. Muller, V. Munz, K. Quantitative and micro-autoradiographic study on mouse intestinal distribution of polycyanoacrylate nanopartides. Int. J. Pharm. 1989, 55, 39-A5. 

PEG-coated (polycyanoacrylate) nanoparticles Paclitaxel Transferrin S-180 bearing mice ... 

Several other biodegradable, biocompatible, injectable polymers are being investigated for drug delivery systems. They include polyvinyl alcohol, block copolymer of PLA-PEG, polycyanoacrylate, polyanhydrides, cellulose, alginate, collagen, gelatin, albumin, starches, dextrans, hyaluronic acid and its derivatives, and hydroxyapatite. ... 

A variety of methods have been used for microsphere formation including non-degradable polystyrene, poly(methyl methacrylate) (PMMA), and polyacrylamide (PAAm) microspheres, as well as PLLA, PGA, PGLA, polycyanoacrylate, starch, and protein microspheres, which would be more likely to be fully biodegradable [42, 110]. Measurable amounts of polystyrene [107] and PAAm microspheres [110] persist in the tissue for many weeks after administration. It seems likely, however, that PGA [108] and protein microspheres [110] may be degraded in vivo in a period of days. 

Spray drying has been proposed as a means of providing a carrier for efficient nanoparticle delivery (Fig. 26). A nanoparticle suspension was spray dried in the presence of lactose, used as a carrier, to demonstrate that nanoparticles remained in the nano-range size after spray drying and provide a means to improve their delivery by inhalation (73). Nanoparticles made out of polystyrene, colloidal silica (20) as well as gelatin and polycyanoacrylate (73) have been spray dried in the presence of lactose DPPC or DMP to improve their drug delivery efficiency. 

A scientific breakthrough in order to design USCAs on demand can be seen in the third generation (Myomap, Quantison, BiSphere and Sonavist). Compared to the more or less free bubbles of the first and second generations, the novel type of USCAs consist of encapsulated microbubbles with a shell formed by a biopolymer (like human albumin) and/or a biocompatible synthetic polymer (like copolymers of poly-lactide and polyglycolide or derivatives of polycyanoacrylate). In addition to the prolongation of the lifetime in the blood stream, these polymer-stabilized microbubbles can be manufactured to fulfill certain needs, and to interact with diagnostic ultrasound in a defined and optimal manner. 

A unified science of adhesion is still being developed. Adhesion can result from mechanical bonding between the adhesive and adherend and/or primary and/or secondary chemical forces. Contributions through chemical forces are often more important and illustrate why nonpolar polymeric materials such as polyethylene are difficult to bond, although polycyanoacrylates are excellent adhesives. Numerous types of adhesives are available such as solvent-based, latex, pressure-sensitive, reactive, and hot-melt adhesives. 

ODNs directed to a point mutation in codon 12 of the HA-ras mRNA adsorbed to such nanoparticles were injected into tumor tissue, and suppressed oncogene-mediated tumor proliferation at concentrations 100 times lower than the free oligonucleotides [435], Because of the negative surface potential ( -potential) of polycyanoacrylate particles, a cationic copolymer such as DEAE-dextran (known as a transfection enhancer), or a hydrophobic cationic detergent such as CTAB, are usually used. In the meantime, base-modified nanoparticles of the methacrylate type have also been described [399-401, 404, 405, 407]. They have shown to increase plasma stability of ODNs and increase cellular uptake. Effects of toxicity were observed depending on the type of modification. As they are also used as car-... 

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