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Debrecen, Hungary

Berko S.,University of Szeged | Maroda M.,Teva Pharmaceuticals Inc. | Bodnar M.,BBS Biochemicals LLC | Eros G.,University of Szeged | And 6 more authors.
European Polymer Journal | Year: 2013

Cross-linking of the hyaluronic acid (hyaluronan, HA) molecule may be a possible chemical modification via which to improve the problem of the penetration of HA. The successful preparation and characterization of stable nanoparticulate systems based on HA were described and discussed previously. The purpose of the present study is to compare hydrogels based on linear or cross-linked HA as potential semisolid drug delivery forms from the aspects of deep HA penetration through the skin. The rheological properties, hydration, irritation effect, in vitro and in vivo skin penetration were studied. The hydration effect was kept and the rheological parameters were slightly changed after the cross-linking procedure. Diffusion and penetration studies demonstrated that the formation of smaller particles of HA by means of cross-linking resulted in better diffusion through a synthetic membrane and better penetration through the human epidermis and living animal skin as compared with linear HA, which did not penetrate. © 2013 Elsevier Ltd. All rights reserved.

Maroda M.,BBS Biochemicals LLC | Maroda M.,University of Szeged | Bodnar M.,BBS Biochemicals LLC | Berko S.,University of Szeged | And 7 more authors.
Carbohydrate Polymers | Year: 2011

The present paper describes the preparation and characterization of hydrophilic hyaluronan nanoparticles formed by cross-linking of hyaluronic acid (HA) with 2,2′(ethylenedioxy)bis(ethylamine) in the presence of water-soluble carbodiimide (CDI) in aqueous media. The particle size of cross-linked nanosystems was measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM), transmittance by UV-VIS spectrophotometry, gel permeation chromatography (GPC) and rheology to characterize the physico-chemical properties. The aqueous nanosystems prepared were stable, transparent or mildly opalescent with values of transmittance above 91%. It was observed, that a fraction of particles with size less than 20 nm, has been released during the purification by diafiltration. It was established that the hydrodynamic size of cross-linked HA nanoparticles can be controlled by variation of the reaction conditions such as concentration of HA, salt concentration of media, ratio of cross-linker and the final pH of the reaction mixture. © 2010 Elsevier Ltd. All rights reserved.

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