Encapsulation and Delivery

Portilla-Arias JA, Camargo B, Garcia-Alvarez M et al (2009) Nanoparticles made of microbial poly(y-glutamate)s for encapsulation and delivery of drugs and proteins. J Biomater Sci Polym Ed 20 1065-1079... 

The electrostatic interaction between oppositely charged protein and polysaccharide can be utilized for encapsulation and delivery of hydro-phobic nutraceuticals. As a result of this interaction, we may have either complex coacervation (and precipitation) or soluble complex formation, depending on various factors, such as the type of polysaccharide used (anionic/cationic), the solution pH, the ionic strength, and the ratio of polysaccharide to protein (see sections 2.1, 2.2 and 2.5 in chapter seven for more details) (Schmitt et al, 1998 de Kruif et al., 2004 Livney, 2008 McClements et al, 2008, 2009). The phenomenon of complex... 

Polymeric vesicles, or polymersomes, are of interest for the encapsulation and delivery of active ingredients. They offer enhanced stability and lower permeability compared to lipid vesicles, and the versatility of synthetic polymer chemistry provides the ability to tune properties such as membrane thickness, surface... 

When the core is an oily liquid, the surrounding polymer is a single layer of polymer, and the vesicle is referred to as a nanocapsule. These systems have found utility in the encapsulation and delivery of hydrophobic drugs Polymers used for the formation of nanocapsules have typically included polyester homopolymers such as poly(D,L-lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA) and poly(caprolactone) PCL [112],... 

In addition, tween 20 reduced the number of aqueous channels between the internal aqueous droplets as well as those communicating with the external medium. The inventors claimed that these results constitute a step ahead in the improvement of an existing technology in controlling protein encapsulation and delivery from microspheres prepared by the multiple solvent evaporation method [215]. 

Du and coworkers [122] prepared vesicles from poly(2-(methacryloyloxy)ethyl phosphorylcholine-fe-2-(diisopropylamino)ethyl methacrylate (PMPC-fe-PDPA) directly in water without any cosolvents. These vesicles are stable at physiological pH and completely dissociate below pH 6. Moreover, they are very close analogues of conventional liposomes due to the biomimetic phosphorylcholine motif. Further research demonstrated that these polymersomes are efficient systems for pH-controlled encapsulation and delivery of DNA [218],... 

Encapsulation and delivery of DNA has also been investigated with poly(amino acid) (poly(AA)) based polymer vesicles. Brown and coworkers synthesized an amphiphilic triblock copolymer from methoxy-poly(ethylene glycol) (mPEG), hydrophobic palmitic acid chains in block segments along a poly-L-lysine (PLL) or... 

Initial work with degradable PEG-PLA vesicles has shown that the encapsulation and delivery of siRNA in vitro is comparable to levels achieved with the commonly used lipoplex of siRNA and Lipofectamine 2000 (LFA) [241],... 

Lavasanifar A, Samuel J, Satari S, Kwon GS. Block copolymer micelles for the encapsulation and delivery of amphotericin B. Pharm Res 2002 19 418-422. 

In general, particulate drug carriers can be used to reverse MDR by three ways (1) intrinsic MDR reversal activities of drug carriers (2) encapsulation and delivery of MDR reversal agents (3) delivery of combinational therapy or unconventional anticancer agents and (4) bypassing the membrane transporter resistance mechanisms. Some researchers also combined more than one of these approaches to obtain additional MDR reversal activity. 

Polymersomes A Synthetic Biological Approach to Encapsulation and Delivery... 

Lomas H, Canton I, MacNeU S, Du J, Armes SP, Ryan AJ, Lewis AL, Battaglia G (2007) Biomimetic pH sensitive polymersomes for efficient DNA encapsulation and delivery. Adv Mater 19 4238- 243... 

Perfectly branched dendrimers have potentially better properties for applications in the field of biomedicine than hyperbranched polymers due to their well-defined and predictable structure and narrow mass distribution, which is important for in vitro and in vivo applications. However, hyperbranched polymers have one very significant advantage, which is their easier preparation by a one-step synthesis. Therefore, hyperbranched polymers are also used in technical applications, for example, as additives, blends, or coating components and as multifunctional cross-linkers. But both, dendrimers and hyperbranched polymers, have been extensively studied in the fields of encapsulation and delivery of drugs, dyes, and genes because of their original branched architecture (Fig. 5.15). Small molecules of interest can be incorporated in the interior cavities of dendritic molecules or bound to their outer functional groups. 

Recent studies also indicated that rosin nanoparticles can he effective for the encapsulation and delivery of drugs [127], Rosin formulations have also been used in the controlled release of carbofurane nematicides, thus allowing the applied doses to be reduced by half and to increase significantly their effectiveness and availability in the soil over longer periods of time [128]. 

Kosaraju S.L., 2005. Colon targeted delivery systems Review of polysaccharides for encapsulation and delivery. Critic. Rev. Food. Sci. Nutr. 45 251-258. 

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