Therapeutic use of hyaluronan

Abstract

Hyaluronan used today as a therapeutic agent in human and animal medicine must be in a highly purified form, free of immunologically active protein molecules, from endotoxin and from inflammatory molecules originating from the tissues or bacterial cultures-the source of hyaluronan. All hyaluronans, whether in liquid or in covalently crosslinked gel form, must have certain elastoviscous properties to be usable for current therapeutic applications. Elastoviscous properties are especially important in the ophthalmic viscosurgical use. The metabolism of hyaluronan is very fast in most tissues, except in the vitreus. The ability of injected hyaluronan with a short half-life time in the joint to accomplish long-lasting analgesia represents a challenge for the design of the various products. The history of the therapeutic use of hyaluronan and its present status is described, with emphasis on its use in ophthalmic surgery and for a long-lasting analgesia in arthritic joints in humans and animals. The use of hyaluronan gels is described in viscoaugmentation as injected into the dermal layer of the skin. Hyaluronan gels were also used as viscosupplements injected into sphincter muscles to improve their function in aging or disease. The use of hyaluronan and its gel for drug delivery was suggested several decades ago, and is also mentioned.

Hyaluronic acid-coated liposomes for active targeting of gemcitabine

“…HA has many physiological roles that include tissue and matrix water regulation, structural and space-filling properties, lubrication and a number of macromolecular functions [25].…”

Polymer Based Therapies for the Treatment of Chronic Pain

“…Over the years, a great deal of research efforts have been put forth to synthesize chemically modified HA [49]. In order to synthesize HA derived viscosupplements, linear HA has been subjected to crosslinking reactions with a number of bifunctional reagents such as diepoxides, divinyl sulfone, epichlorohydrin etc [50,51]. Some representative examples of crosslinking chemistries that were carried out to prepare HA based hydrogels are shown in Figure 2.…”

Rheological Studies Dedicated to the Development of a Novel Injectable Polymeric Blend for Viscosupplementation Treatment

“…High molecular weight products and crosslinked hydrogels have been developed, but they are able to retard the hyaluronidases attack without preventing it. 27 Furthermore, inflammatory reactions sometimes accompanied by swelling and erythema have also been variably reported. 28,29 A new derivative similar to HA, but with a better behaviour in terms of hardness and stability towards enzymatic degradation 30 has been developed converting 50 % of the carboxylic groups of carboxymethylcellulose (CMC) into amidic groups to obtain the amidated carboxymethylcellulose (CMCA).…”