Drug Delivery and Controlled Release

Magnetic and Electron Transport Behaviors of Conductive-Polymer Nanocomposites 

Conductive conjugated polymers belonging to polyenes or polyaromatics, such as polyacetylene, polyanUine (PANl), polypyrrole (PPy), polythiophene, poly(p-phenylene), and poly(phenylene vinylene) classes, have been investigated extensively [1-3]. PANI and PPy families of conjugated polymers are of much interest due to their low cost, easy synthesis, unique conduction mechanism, good stability and environmentally benign performance [4,5], 

Nanostructured Conductive Polymers Edited by Ali Efteldian 2010 Jdm Wiley Sons, Ltd 

Composites are engineered materials made from two or more constituent materials with significandy different physical or chemical properties which remain separate and distinct on a macroscopic level within the finished structure. Nanocomposites can be defined [18] as multiphase solid materials, in which at least one of the phases has a dimension of less than 100 nanometers (nm). In other words, the stmctures have nanometer-scale dimensional repeat distances between the different phases that make up the unity. In the broadest sense this definition can include colloids, porous (mesoporous) media, gels, and copolymers, but is more usually taken to mean the solid combination of nanodimensional phases differing in properties due to dissimilarities in structure and chemistry. The properties of the nanocomposites are different from the bulk composites. 

Polymer-based nanocomposites reinforced with nanoparticles (NPs) have attracted much interest due to their homogeneity, relatively easy processability, and tunable physicochemical properties, such as mechanical, magnetic, electric, thermoelectric, and electronic properties [2,19-36], High particle loading is required for certain industrial applications, such as electromagnetic-wave absorbers [37,38], photovoltaic cells (solar cells) [39,40], photo detectors, and smart structures [41 3]. A nanoparticle core with a polymer shell renders many industrial applications possible, such as nanofluids and magnetic resonance imaging (MRI). 

---

The biomedical use of polyphosphazenes for drug delivery and controlled release systems still draws considerable attention. It has been demonstrated for the degradable polymer [NP(NHCH2C02Et)2]n that the rate of degradation increases by partially replacement of the ethyl glycinate groups by small amounts... 

These results were the first investigation regarding the relationship between the cytotoxicity of silica and the population doubling time of different cell lines as well as the benefits of using chitosan to prepare composite silica nanoparticles. They would be relevant for future applications of silica nanoparticles in drug delivery and controlled release applications. 

De Angelis F, Pujia A, Falcone C, laccino E, Palmier C, Liberale C, Mecarini F, Candeloro P, Luberto L, De Laurentiis A (2010) Water soluble nanoporous nanoparticle for in vivo targeted drug delivery and controlled release in B cells tumor context. Nanoscale 2(10) 2230-2236 Finkel T, Holbrook NJ (2000) Oxidants, oxidative stress and the biology of ageing. Nature... 

MIP-CNTs nanocomposites are also proposed as innovative drug dehveiy devices (Yin et al., 2010). MIP nanotubes were fabricated by atom transfer radical polymerization (ATRP) and applied in enantioselective drug delivery and controlled release. Authors found that S-propranolol imprinted nanotubes provided differential release of enantiomers, whereby the release of the more therapeutically active S-propranolol (eutomer) is greatly promoted whilst the release of the less active R-enantiomer (distomer) is retarded. 

Yin, J. Cui, Y. Yang, G. Wang H. (2010). Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release. Chemical Communications, 46, 7688-7690. 

Mesoporous Silica Nanoparticles for Drug Delivery and Controlled Release Applications... 

---