Polysaccharides carbohydrate-based delivery

Abstract Carbohydrates have been investigated and developed as delivery vehicles for shuttling nucleic acids into cells. In this review, we present the state of the art in carbohydrate-based polymeric vehicles for nucleic acid delivery, with the focus on the recent successes in preclinical models, both in vitro and in vivo. Polymeric scaffolds based on the natural polysaccharides chitosan, hyaluronan, pullulan, dextran, and schizophyllan each have unique properties and potential for modification, and these results are discussed with the focus on facile synthetic routes and favorable performance in biological systems. Many of these carbohydrates have been used to develop alternative types of biomaterials for nucleic acid delivery to typical polyplexes, and these novel materials are discussed. Also presented are polymeric vehicles that incorporate copolymerized carbohydrates into polymer backbones based on polyethylenimine and polylysine and their effect on transfection and biocompatibility. Unique scaffolds, such as clusters and polymers based on cyclodextrin (CD), are also discussed, with the focus on recent successes in vivo and in the clinic. These results are presented with the emphasis on the role of carbohydrate and charge on transfection. Use of carbohydrates as molecular recognition ligands for cell-type specific dehvery is also briefly... 

Apart from polyplexes, various nanoscale assemblies of cationic polysaccharides are also proposed to promote the surface-mediated delivery of DNA to cells. These approaches are classified into one of two broad categories (i) methods based upon the physical adsorption of preformed polyplex on polymeric surfaces like PLGA or collagen films and these polyplex functionalized films promoted surface-mediated transfection of cells in vitro and in vivof (ii) methods for layer-by-layer adsorption of DNA and cationic polymers on surfaces to fabricate multilayered thin films. Recently, degradable carbohydrate-based nanogels were proposed for codelivery of pDNA and therapeutic proteins. These systems were designed to possess stimuli-sensitive characteristics where the temperature-sensitive property of nanogels allowed the facile encapsulation of biomaterials, while... 

Bhaw-Luximon A (2011) Modified natural polysaccharides as nanoparticulate drug delivery devices. In Narain R (ed) Engineered carbohydrate-based materials for biomedical applications-polymers, surfaces, dendiimers, nanopaitieles, and hydrogels. Wiley, Hoboken... 

A number of factors must be considered when selecting a suitable polysaccharide or combination of polysaccharides to fabricate a biopolymer-based delivery system. It is important to establish suitable environmental and solution conditions in which the polysaccharide molecules can associate with other polysaccharide or non-polysaccharide structure-forming molecules. To do so, one needs to know the physicochemical properties of the polysaccharides involved, such as helix-coil transition temperatures (for carrageenan, alginate,pectin) electrical properties (pKa values) sensitivity to specific monovalent or multivalent ions or susceptibility to enzyme or chemical reactions (BeMiller and Whistler, 1996). The most widely used carbohydrates for encapsulation purposes are probably alginates (Kailasapathy and Champagne, 2011 Kainmani et al, 2011), starch (Li et al, 2009) and its linear biopolymer amylose (Lalush et al, 2005). 

Garcia-Gonzalez, C.A., Alnaief, M., Smirnova, I., 2011. Polysaccharide-based aerogels— promising biodegradable carriers for drug delivery systems. Carbohydr. Polym. 86 (4), 1425-1438. 

Delair (2012). In situ forming polysaccharide-based 3D-hydrogels for cell delivery in regenerative medidne. Carbohydrate Polymers, 87(2), 1013-1019 Doi http // dx.doi.org/10.1016/j.carbpol.2011.09.069... 

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