Chitosan hyaluronic acid

Biodegradable polymers, both synthetic and natural, have gained more attention as carriers because of their biocompatibility and biodegradability and therewith the low impact on the environment. Examples of biodegradable polymers are synthetic polymers, such as polyesters, poly(orfho-esters), polyanhydrides and polyphosphazenes, and natural polymers, like polysaccharides such as chitosan, hyaluronic acid and alginates. 

Mucoadhesives are generally macromolecular organic polymers made from natural (gelatin, agarose, chitosan, hyaluronic acid) or synthetic polymers (polyvinylpyrrolidone (PVP), polyacrylates, polyvinyl alcohol, cellulose derivates). They possess hydrophilic groups that can... 

Duceppe N, Tabrizian M (2009) Factors influencing the transfection efficiency of ultra low molecular weight chitosan/hyaluronic acid nanoparticles. Biomaterials 30(13) 2625-2631... 

Small drugs, as are most pharmaceuticals, can be directly loaded in the preformed films [56-58], Schneider demonstrated that chitosan/hyaluronic acid (CHI/HA)... 

There are many kinds of natural biodegradable polymers. They are classified into three types according to their chemical structures, i.e., polysaccharides, polypeptides/proteins and polynucleotides/nucleic acids. Among them, polysaccharides, such as cellulose, chitin/chitosan, hyaluronic acid and starch, and proteins, such as silk, wool, poly( y-glutamic acid), and poly(e-lysin), are well known and particularly important industrial polymeric materials. 

From among the natural carbohydrate polymers, we mention here cellulose, chitin and its deacetylated form chitosan, hyaluronic acid (hyaluronan), and heparin. Apart from cellulose, the monomer-unit sequences are not strictly regular, but the structures given below are representative. Chitosan, hyaluronic acid, and heparin are water-soluble because they carry electrically-charged functions. Since cellulose and chitin are insoluble in water, most of their radiation chemistry has been done in the solid state, as discussed below. Yields of molecular-weight reduction have usually been determined by viscosimetry and, more recently, by the laser light-scattering technique. 

Another approach to improve the properties of chitosan hydrogels is via the preparation of polymer composites. Porous hydrogels of N-carboxymethyl chitosan/polyvinyl alcohol were prepared by Lee et al. [99]. Hydroxypropyl chitosan was combined with sodium alginate for the formation of biodegradable hydrogels [100]. Chitosan-hyaluronic acid composite was prepared by Tan et al. [101]. 

Tan HP, Chu CR et al (2009) Injectable in situ forming biodegradable chitosan-hyaluronic acid based hydrogels for cartilage tissue engineering. Biomaterials 30 2499-2506... 

Fabrication Common preparation techniqnes discussed in earlier sections are nsed in formnlating bioadhesive microspheres. An important criterion is the use of bioadhesive polymers like chitosan, hyaluronic acid, starch, lysophosphatidylcholine along with degradable starch microspheres. 

H. Li, Y. Ge, R Zhang, L. Wu, S. Chen, The effect of layer-by-layer chitosan-hyaluronic acid coating on graft-to-bone healing of a polyfethylene terephthalate) artificial Ugament, J. Biomater. Sci. Polym. Ed. 23 (2012) 425 38. 

Oxidized hyaluronic acid was coupled with chitosan to form porous scaffolds after freeze drying. The proportion of porosity of the freeze-dried chitosan-hyaluronic acid dialdehyde composite (CHDA) gels enhanced with augmentation in oxidation. Fibroblast cells seeded onto CHDA porous scaffold adhered, proliferated and offered extracellular matrix components on the scaffold [99]. Chondrocytes encapsulated in CHDA gels retained their viability and specific phenotypic features. The gel material is therefore projected as a scaffold and encapsulated material for tissue engineering applications. Films of hyaluronan (HA) and a phosphoryl choline-modified chitosan (PC-CH) were constructed by the electrolyte multilayer (PEM)... 

Natural biocompatible and biodegradable macromolecules, especially plant-derived biopolymers, are more accessible, eco-friendly and cost-effective as compared with synthetic polymers [7-11], Thus, starch, dextran, cellulose, pectins, alginates, agar, gums, chitosan, hyaluronic acid, collagen, and gelatin are viable alternatives to synthetic polymers in pharmaceutical technology [12-16]. 

In situ cross-linkable chitosan-hyaluronic acid based hydrogels for preventing postoperative adhesion has been developed [153]. Hyalmonic acid was oxidized with sodium periodate which cleaves carbon-carbon bonds to create aldehyde groups in D-glucuronic acid units of the molecular chain. The solubility of chitosan in neutral aqueous solution was improved by incorporating carboxymethyl... 

Nath, S.D., Abueva, C., Kim, B., Lee, B.T., 2015. Chitosan-hyaluronic acid polyelectrolyte complex scaffold crossbnked with genipin for immobilization and controlled release of BMP-2. Carbohydr. Polym. 115, 160-169. 

Park, H., Choi, B., Hu, I.L., Lee, M. Injectable chitosan hyaluronic acid hydrogels for cartilage tissue engineering. Acta Biomater. 9,4779 786 (2013)... 

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