Current Pharmaceutical Biotechnology - Volume 9, Issue 4, 2008

In 1934, the polysaccharide hyaluronan [hyaluronic acid or HA] was extracted from bovine eyes by Karl Meyer. As of early 2008, >22,000 research papers on HA-related science, >1,500 US patents with HA claims, and a ∼$1.5 billion/year market (“Global Markets for Hyaluronic Acid” Millenium Research 2006) definitively prove the value of HA. This sugar polymer is in the same chemical family as heparin, an anticoagulant and a Read More

Hyaluronan solutions known as ophthalmic viscoelastic devices (OVDs) are used in surgical procedures within the eye and on the surface of the eye to prevent dryness and to facilitate wound healing. HA and a variety of derivatives facilitate procedures including vitreoretinal surgery, anterior segment surgery, glaucoma surgery, and corneal transplantation.

Presently, the two main commercial sources of hyaluronic acid (HA) are rooster combs and streptococci. Harvesting from rooster combs is complex and costly. Streptococci are difficult to genetically manipulate and require complex media for growth. Both sources have potential problems with unwanted by-products, such as allergens and toxins. These problems can be solved by producing the HA with safe bacilli t Read More

Hyaluronan (HA) is a very useful polymer, but its properties sometimes need to be altered or enhanced by chemical modification for biomedical applications. A wide variety of HA derivatives are currently used for eye surgery, joint viscoelastic supplementation, and anti-adhesion films. The future promises to deliver new classes of HA-based reagents as well as new polymers that can be used in situ with living cells or within the body.

In many cases, the cellular response to hyaluronan (HA) depends on the molecular weight (MW) of the polymer chain. Most HA preparations from Nature or its derivatives possess wide size distributions called polydisperse. New chemoenzymatic synthesis technology allows the production of very narrow size distribution polymers called monodisperse. The use of stoichiometrically controlled and synchronized polymerization re Read More

Hyaluronan (HA) polysaccharide has differential effects on cells depending on polymer size. One of the more exciting findings is that small chains or oligosaccharides of HA (6-18 sugar units), but not large polymers, will kill many types of cancer cells by triggering apoptosis while leaving normal cells unaffected. Even chemoresistant cells become drug-sensitive when co-treated with HA oligosaccharides. Overall, these observation Read More

Despite advances in chemotherapeutic regimens, the treatment of metastatic cancer remains a challenge. A key problem with chemotherapy drugs is nonspecific drug distribution, resulting in low tumor concentrations and systemic toxicity. The holy grail of clinical cancer research has been to establish more specific ways of directing therapeutics to tumors, whether through more targeted anti-cancer agents or via the metho Read More

Biofilm formation occurs spontaneously on both inert and living systems and is an important bacterial survival strategy. In humans bioflms are responsible for many pathologies, most of them associated with the use of medical devices. A major problem of biofilms is their inherent tolerance to host defences and antibiotic therapies; there is therefore an urgent need to develop alternative ways to prevent and control biofilm-a Read More

The concept of probiotics now has been around for more than a century, with its consumption increasing exponentially; owing to exciting scientific and clinical findings, limiting side effects of existing pharmaceutical agents and increased consumer demand for natural products. But, the evidence for their safety and efficacy has largely been anecdotal, lacking an integrated scientific basis. Clinical studies conducted with p Read More

Jatropha curcas is a stress - resistant perennial plant growing on marginal soils. This plant is widespread throughout arid and semiarid tropical regions of the world and has been used as a traditional folk medicine in many countries. J.curcas is a source of several secondary metabolites of medicinal importance. The leaf, fruits, latex and bark contain glycosides, tannins, phytosterols, flavonoids and steroidal sapogenins that Read More

Silkworm pupae protein is a good source of high quality protein. The hydrolyzates of silkworm pupae protein catalyzed by neutrase, pepsin, acidic protease (Asperqiius usamii NO. 537), flavourzyme, alcalase, and trypsin with inhibitory activity on angiotensin I-converting enzyme (ACE) were identified by HPLC. The hydrolyzates catalyzed by acidic protease exerted the highest inhibitory activity on ACE. The hydrolyzing conditio Read More

Jatropha curcas is a drought resistant, perennial plant that grows even in the marginal and poor soil. Raising Jatropha is easy. It keeps producing seeds for many years. In the recent years, Jatropha has become famous primarily for the production of biodiesel; besides this it has several medicinal applications, too. Most parts of this plant are used for the treatment of various human and veterinary ailments. The white late Read More

Caffeine and other methylxanthines produce multiple physiologic effects throughout the human body, many of these effects could potentially modulate the activity of anticancer therapy. Caffeine may directly interfere with drug transport to tumor cells by formation of mixed stacking complexes with polyaromatic drugs. If formed in cells, these complexes may also prevent of intercalating drugs from DNA binding and, i Read More