Insights on the reactivity of chondroitin and hyaluronan toward 1,4-butanediol diglycidyl ether.

Hyaluronic acid (HA) cross-linked with 1,4-butanediol diglycidyl ether (BDDE) are hydrogels with many biomedical applications. Degree of substitution, cross-linking and substitution position of the cross-linker might influence the properties of the hydrogels. We showed earlier that the most common substitution position of the cross-linker on the hyaluronan chain was the 4-hydroxyl of N-acetylglucosamine.

1D NMR methods for determination of degree of cross-linking and BDDE substitution positions in HA hydrogels.

Hyaluronic acid polymers cross-linked with BDDE are today among the most used hydrogels for biomedical applications. The physical properties of the hydrogels depend, among other parameters, on the degree of cross-linking of HA. Another parameter likely to affect the physical properties is the substitution position of the linker on the HA functional groups.

Determination of substitution positions in hyaluronic acid hydrogels using NMR and MS based methods.

In hydrogels of cross-linked polysaccharides, the total amount of cross-linker and the degree of cross-linking influence the properties of the hydrogel. The substitution position of the cross-linker on the polysaccharide is another parameter that can influence hydrogel properties; hence methods for detailed structural analysis of the substitution pattern are required. NMR and LC-MS methods were developed to determine the positions and amounts of substitution of 1,4-butanediol diglycidyl ether (BDDE) on hyaluronic acid (HA), and for the first time it is shown that BDDE can react with any of the four available hydroxyl groups of the HA disaccharide repeating unit.

Modification and cross-linking parameters in hyaluronic acid hydrogels--definitions and analytical methods.

Definitions and methods for the quantification of degree of modification and cross-linking in cross-linked hyaluronic acid (HA) hydrogels are outlined. A novel method is presented in which the HA hydrogel is degraded by the enzyme chondroitinase AC and the digest product analyzed by size exclusion chromatography combined with electrospray ionization mass spectrometry (SEC-ESI-MS). This method allows for the determination of effective cross-linker ratio (CrR) which together with the degree of modification (MoD), determined by, e.

Gel properties of hyaluronic acid dermal fillers.

Background: Most of the hyaluronic acid (HA)-based dermal fillers currently on the market are chemically modified with cross-linkers to improve the mechanical properties and duration in vivo.

Objective: To investigate differences in the properties of dermal fillers that can be related to the respective cross-linking and manufacturing methods used.

Methods And Materials: Thirteen commercially available HA fillers were analyzed.

Intra-articular Duration of Durolane™ after Single Injection into the Rabbit Knee.

Objective: The aim of the present study was to investigate the intra-articular duration of Durolane™ in a rabbit model to allow comparison between Durolane™ residence time and data reported for other hyaluronic acid products as well as native hyaluronic acid.

Design: (14)C-labeled Durolane™ was manufactured by labeling the cross-linker used for stabilization. A single injection of approximately 0.