Scandinavian Researchers Discover Potential Arthritis Treatment

The natural polysaccharide alginate and particularly its sulfated derivatives have potent anti-oxidant, anti-inflammatory, and anti-immunogenic properties, which indicate that it may be a promising biomaterial to be explored for treatment of arthritis.

Degeneration of articular cartilage represents one of the most common causes of pain and disability in our aging society. Current treatments only address the symptoms of joint disease, but not their underlying causes which include oxidative stress and inflammation in cartilage and surrounding tissues. Sulfated biopolymers that mimic aspects of the native extracellular environment of cartilage are recently gaining interest as a means to slow the inflammatory events responsible for tissue degeneration.

In searching for new approaches to treating arthritis, investigators at ETH Zurich (Switzerland), the Swiss Federal Laboratories for Materials Science and Technology (St. Gallen, Switzerland), and the Norwegian research institute SINTEF (Trondheim, Norway) worked with alginate, a long-chain polysaccharide isolated from the brown algae Laminaria hyperborea.

The investigators reported in the June 16, 2017, online edition of the journal Biomaterials Science that alginate - and particularly its sulfated derivatives - have potent anti-oxidant, anti-inflammatory, and anti-immunogenic properties in vitro. They found that these polymers exerted a free radical scavenging activity in a sulfation-dependent manner. In particular, the sulfation degree of substitution of alginate directly correlated with its ability to scavenge superoxide radicals and to chelate metal ions.

The investigators also studied the effect of sulfated alginate on the ability of IL-1beta (Interleukin 1beta) to stimulate inflammatory genes in human chondrocytes and found decreased expression of the pro-inflammatory markers IL-6 and CXCL8 (IL8), which inversely correlated with the sulfation degree. Moreover, in studies testing the ability of the alginates to modulate macrophage polarization, the investigators found that they decreased both the gene expression and synthesis of the proinflammatory cytokine TNF-alpha (Tumor necrosis factor-alpha) in human THP-1 macrophages with M1-like phenotype in a sulfation-dependent manner. Thus, sulfated alginates effectively protected against oxidative stress and inflammation in vitro and should be a promising biomaterial to be explored for treatment of osteoarthritis.

Related Links:
ETH Zurich
Swiss Federal Laboratories for Materials Science and Technology
SINTEF