Sodium hyaluronate applications

A special production process was developed for the production of sodium hyaluronate through microbial fermentation with streptococci. It is possible to produce different sodium hyaluronates with varying molecular weights for diverse pharmaceutical and cosmetic applications. The company, Fermentech (London, England), for instance, produces sodium hyaluronate in this manner. The process employed, however, is continuous, as opposed to the otherwise standard production of individual batches. In batch cultures, cells are found at varying stages of the cell cycle, and therefore, at different metabolic states. That is to say, some or-... 

HPMC products are not suitable to maintain anterior chamber depth with concomitant increased vitreous pressure due to their low elasticity. Higher molecular weight sodium hyaluronate was proven to be superior for this clinical application (Strobel, 1997). 

Charteris and co-workers (1991) observed the formation of thin-walled filtration blebs with more microcysts than in the controls following subconjunctival and subscleral application of 1 % sodium hyaluronate. 

Limberg MB, McCaa C, Kissling GE, Kaufman HE. Topical application of hyaluronic acid and chondro-itin sulfate in the treatment of dry eyes. Am J Ophthalmol 1987 103 194-197 Lindquist TD, Edenfield M. Cytotoxicity of viscoelastics on cultured corneal epithelial cells measured by plasminogen activator release. J Refract Corneal Surg 1994 10 95-102 MacRae SM, Edelhauser HE, Hyndiuk RA, Burd EM, Schultz RO. The effects of sodium hyaluronate, chondroitin sulfate, and methylcellulose on the corneal endothelium and intraocular pressure. Am J Ophthalmol 1983 95 332-341... 

Mengher LS, Pandher KS, Bron AJ, Davey CC. Effect of sodium hyaluronate (0.1%) on break-up time (NIBUT) in patients with dry eyes. Br J Ophthalmol 1986 70 442-447 Meyer DR, McCulley JP. Different prospects of risk management from in vitro toxicology and its relevance to the evolution of viscoelastic formulations. Rosen ES (ed) Viscoealstic Materials Basic Science and Clinical Applications. New York, Pergamon Press, 1989, S. 45-90 Meyer K, Palmer JW. The polysaccharide of the vitreous humor. J Biol Chem 1934 107 629-634 Meyer K. Chemical structure of hyaluronic acid. Fed Proc 1958 17 1075-1077... 

Stamper RL, DiLoreto D, Schacknow P. Effect of intraocular aspiration of sodium hyaluronate on postoperative intraocular pressure. Ophthalmic Surg 1990 21 486-491 Steele ADM. Viscoelastic materials in keratoplasty. Trans Ophthalmol Soc UK 1983 103 268-269 Steele EA. Hydroxypropyl methylcellulose used as a viscoelastic fluid in ocular surgery, in Rosen ES (ed) Viscoelastic Materials Basic Science and Clinical Applications. New York, Pergamon Press, 1989,S. 161-163... 

Stenkula S. Sodium hyaluronate as a vitreous substitute and intravitreal surgical tool. Rosen ES (ed) Viscoelastic Materials Basis Science and Clinical Applications. New York, Pergamon Press, 1989, S. 157-160... 

Subsequent advances in the polymers field with respect to ocular drug delivery have led to the use of poly(vinyl alcohol) (PVA) sodium hyaluronate, and car-bomer, which often give better results [21-24] than celluloses. On the other hand cellulose-based hydrogels are still in focus for ophthalmical applications as ocular bandage [25]. 

HA was first isolated from bovine vitreous humor in acid form by Karl Meyer and John Pahner of Columbia University in 1934. They named the new pwlysaccharide hyaluronic acid, meaning uronic acid from hyaloid (vitreous). The term hyaluronan was introduced by Endre Balazs in 1986 to encompass the different forms the molecule can take—for example, the add form, hyaluronic acid, and the salts, such as sodium hyaluronate, which form at physiological pH [17]. Endre Balazs pioneered the medical use of HA. He derived the main concepts for many applications and... 

Besides the previously mentioned collagen, a wide variety of natural polymers have been involved in the synthesis of bio-nanohybrid materials with potential application in bone repair and dental prostheses. For instance, some recent examples refer to bionanocomposites based on the combination of HAP with alginate [96,97], chitosan [98,99], bovine serum albumin (BSA) [100], sodium caseinate [101], hyaluronic acid [102], silk fibroin [103,104], silk sericin [105], or polylactic add (PLA) [106,107]. These examples illustrate the increasing interest in the subject of HAP-based biohybrid materials, which has led to almost 400 articles appeared in scientific journals in 2006 alone. 

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