Polyurethane nanoparticles

M.B. Fritzen-Garcia, B.G. Zanetti-Ramos, C.S. De Oliveira, V. Soldi, A. Pasa, and T.B. Creczynski-Pasa, Atomic force microscopy imaging of polyurethane nanoparticles onto different solid substrates. Mat. Sci. Eng. C., 29(2), 405-409 (2009). 

FIGURE 23.1 Mechanism of targeted drug deUvery and cell internahzation into tumor cells using multiblock multifunctional polyurethane nanoparticles. Reprinted with permission from Ref. [38]. Copyright 2013. American Chemical Society. 

Millable polyurethane elastomers are prepared from bi-functional castor oil or its blends, with poly(propylene glycol) at two different ratios of 1 4-butane diol as a chain extender and TDI. Castor oil-based polyurethane nanoparticles with an average diameter of 300 nm are prepared by a... 

Ou C, Su C, Jeng U, Hsu S. Characterization of biodegradable polyurethane nanoparticles and thermally induced self-assembly in water dispersion. Acs Appl Mater Interfaces April 23, 2014 6(8) 5685-94. 

Chen YP, Hsu SH. Preparation and characterization of novel water-based biodegradable polyurethane nanoparticles encapsulating superparamagnetic iron oxide and hydrophobic drugs. J Mater Chem B 2014 2 3391 01. 

Nano-anulsions constitute an attractive alternative for preparing polyurethane nanoparticles because of their small droplet size and, consequently, very large surface area and high kinetic stabiUty. - Nano-emulsions are a class of emulsions with a uniform and extremely small droplet size, usually ranging between 20 and 200 nm. They can be classified as oil-in-water (OAV) or water-in-oil (W/O) nano-emulsions if the internal phase is constituted by oil or aqueous droplets dispersed in aqueous or oily external phase, respectively. Therefore both hydrophobic and hydrophilic... 

Multifunctional biotinylated and streptavidin-coated polyurethane-urea nanoparticles have also been engineered from OAV nano-emulsions." " In these studies, biotin or streptavidin reacts with diisocyanate at the droplet interface and are successfully attached to the nanoparticle polymeric matrices. These nanoparticles exhibit diameters around 110-140mn (biotin nanoparticles) and 70-74nm (streptavidin nanoparticles). In addition, streptavidin-coated polyurethane-urea nanoparticles were functionalized with biotin anti-VCAM-1 and anti-ICAM-1 antibodies for specific targeting. Both nanoparticulate systems showed no cytotoxicity in healthy endothelial cells and therefore good biocompatibility properties. Figure 7.1 shows a schema of the synthesis of different polyurethane nanoparticles obtained from 0/W nano-emulsions by interfacial polymerization and images obtained by transmission electron microscopy. 

The formation of polyurethane nanoparticles from inverse nano-emulsions (W/O) has also been achieved. Interfacial polyaddition in inverse nano-emulsion is of special interest since this allows the encapsulation of hydrophilic active materials such as proteins or nucleic acids. Thus, taking advantage of the high reactivity of tolylene 2,4-diisocyanate with water molecules, polyurea lipid nanocapsules with aqueous cores obtained from W/O nano-emulsions and prepared by PIT method were designed. Polymer synthesis occurs by in situ interfacial polymerization after nano-emulsion formation. Volatile oils employed as the continuous phase were removed by evaporation and the nanocapsules were redispersed in water. These nanocapsules could be potentially used for encapsulation of both hydrophilic and lipophilic molecules simultaneously. 

Figure 7.1 Fonnation of different polyurethane nanoparticles (naked polyurethane, pegylated pol5mrethane, lysine-coated polyurea, biotinylated polyurethane-urea/pc DNA complex, and functionalized streptavidin-coated polyurethane-urea nanoparticles) obtained by interfacial polycondensation from O/W nano-emulsions (a) and transmission electron micrographs of polyurethane nanoparticles after being negatively stained with 1% v/v uranyl acetate (b).

Significant advances have been made in the design, formation, and characterization of polyurethane nanoparticles. Different approaches have been employed to synthesize polyurethane nanoparticles as carriers of imaging agents, as dmgs, or as copolymers to form different versatile matrices. The chemical reactivity and properties of these polymers make them suitable to bind peptides, nucleic acids, antibodies. 

Zhu Q, Wang Y, Zhou M, Mao Ch, Huang X, Bao J, et al. Preparation of anionic polyurethane nanoparticles and blood compatible behaviors. JNanosc Nanotech 2012 12(5) 4051-6. 

Zanetti-Ramos BG, Lemos- Senna E, Soldi V, Borsali R, Cloutet E, Cramail H. Polyurethane nanoparticles from a natural polyol via miniemulsion technique. Polymer 2006 47 8080-7. 

Dessy A, Piras AM, Alderighi M, Sandreschi S, Chiellini F. Doxorubicin loaded polyurethanes nanoparticles. Nano BiomedEng 2012 4(2) 83-8. 

Temperature- and pH-responsive PU-based nanoparticles Doxorubicin Hexamethylene diisocyanate (HDl) and 4,4 -diphenylmeth-ane diisocyanate (MDl)-based PUs showed temperature-and pH-responsive properties Efficient encapsulation into polyurethane nanoparticles and uptaken by Huh-7 cells HDI-based PUs were nontoxic [29]... 

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