Microparticle drug delivery, nanoparticle

Key Words shRNA RNAi Biodegradable polymer Natural polymer Synthetic polymer Non-viral gene delivery Drug delivery Nanoparticle Microparticle Tumor targeting. 

Konjac glucomannan Extrusion Nanoparticles microparticles Drug delivery... 

A large variety of drug delivery systems are described in the literature, such as liposomes (Torchilin, 2006), micro and nanoparticles (Kumar, 2000), polymeric micelles (Torchilin, 2006), nanocrystals (Muller et al., 2011), among others. Microparticles are usually classified as microcapsules or microspheres (Figure 8). Microspheres are matrix spherical microparticles where the drug may be located on the surface or dissolved into the matrix. Microcapsules are characterized as spherical particles more than Ipm containing a core substance (aqueous or lipid), normally lipid, and are used to deliver poor soluble molecules... 

Nanoparticles show great promise as devices for the controlled release of drugs, provided that the choice of material for nanoparticle formation is made with the appropriate considerations of the drug cargo, administration route, and the desired site of action. The use of nano- and microparticles as controlled drug-delivery devices has recently been extensively reviewed [97]. 

Microparticles and nanoparticles present some advantageous features, namely mucoadhesive properties. They have demonstrated some potential in vaginal drug delivery, particularly in the formulation of delivery systems for vaccines or peptides and proteins [160, 161], Nonetheless, these particles have to be incorporated in adequate carrier systems in order to be delivered. This task has been shown to be complex, it being hard to achieve controlled-release and steady-release profiles. 

Brannon-Peppas, L. Recent advances on the use of biodegradable microparticles and nanoparticles in controlled drug delivery. Int. J. Pharm. 1995, 116, 1-9. 

Figure 1 Formulation of controlled drug delivery systems using the supercritical fluid-derived RESS process (A) films, (B) microparticles/nanoparticles/ liposomes, (C) coated products including microcapsules, and (D) microporous foams.

Nanoparticles and/or capsules are colloidal drug delivery systems whose size ranges from 1 to 1000 nm. Similar to microparticles, nanoparticles also offer... 

Figure 9.24 Particles for drug delivery. Particulate delivery systems include (a) microcapsules, (b) microparticles, and (c) surface-modified nanoparticles. In the nanoparticles, the drug is entrapped in the solid pol)mier core.

Commercially, pullulan is produced by a fermentation process. A fungus Aureobasidium pul-lulans grows on a carbohydrate substrate. Then A. pullulans is harvested, followed by the rupture of cell with either enzyme or physical force. Pullulan then is extracted using simple water extraction process. The process is completely eco-friendly and therefore pullulan can be used for drug delivery. Pullulan hydrogel microparticles or nanoparticles are used for oral administration of gastro-sensitive drugs. 

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