Unsulfated biotechnological chondroitin by itself as well as in combination with high molecular weight hyaluronan improves the inflammation profile in osteoarthritis in vitro model.

Several studies suggest that inflammation has a pivotal role during the progression of osteoarthritis (OA) and cytokines have been identified as the main process mediators. This study aimed to explore the ability to modulate the main OA pro-inflammatory biomarkers of novel gels (H-HA/BC) based on high molecular weight hyaluronan (H-HA) and unsulfated biotechnological chondroitin (BC). For the first time, BC was tested also in combination with H-HA on human primary cells isolated from pathological knee joints. Specifically, the experiments were performed using an OA in vitro model based on human chondrocytes and synoviocytes. To evaluate the anti-inflammatory effects of H-HA/BC in comparison with H-HA and BC single gels, NF-kB, COMP-2, MyD88, MMP-13 and a wide range of cytokines, known to be specific biomarkers in OA (e.g., IL-6, IL-8, and TNF-α), were evaluated. In addition, cell morphology and proliferation occurring in the presence of either H-HA/BC or single components were assessed using time-lapse video microscopy. It was shown that synovial fluids and cells isolated from OA suffering patients, presented a cytokine pattern respondent to an ongoing inflammation status. H-HA and BC significantly reduced the levels of 23 biomarkers associated with cartilage damage. However, H-HA/BC decreased significantly 24 biological mediators and downregulated 19 of them more efficiently than the single components. In synoviocytes cultures, cytokine analyses proved that H-HA/BC gels re-established an extracellular environment more similar to a healthy condition reducing considerably the concentration of 11 analytes. Instead, H-HA and BC significantly modulated 7 (5 only with a longer treatment) and 8 biological cytokines, respectively. Our results suggest that H-HA/BC beyond the viscosupplementation effect typical for HA-based gels, can improve the inflammation status in joints and thus could be introduced as a valid protective and anti-inflammatory intraarticular device in the field of Class III medical devices for OA treatments.

A Study for the Access to a Semi-synthetic Regioisomer of Natural Fucosylated Chondroitin Sulfate with Fucosyl Branches on N-acetyl-Galactosamine Units.

Fucosylated chondroitin sulfate (fCS) is a glycosaminoglycan found up to now exclusively in the body wall of sea cucumbers. It shows several interesting activities, with the anticoagulant and antithrombotic as the most attractive ones. Its different mechanism of action on the blood coagulation cascade with respect to heparin and the retention of its activity by oral administration make fCS a very promising anticoagulant drug candidate for heparin replacement. Nonetheless, its typically heterogeneous structure, the detection of some adverse effects and the preference for new drugs not sourced from animal tissues, explain how mandatory is to open an access to safer and less heterogeneous non-natural fCS species. Here we contribute to this aim by investigating a suitable chemical strategy to obtain a regioisomer of the natural fCS polysaccharide, with sulfated l-fucosyl branches placed at position O-6 of N-acetyl-d-galactosamine (GalNAc) units instead of O-3 of d-glucuronic acid (GlcA) ones, as in natural fCSs. This strategy is based on the structural modification of a microbial sourced chondroitin polysaccharide by regioselective insertion of fucosyl branches and sulfate groups on its polymeric structure. A preliminary in vitro evaluation of the anticoagulant activity of three of such semi-synthetic fCS analogues is also reported.

A Modular Approach to a Library of Semi-Synthetic Fucosylated Chondroitin Sulfate Polysaccharides with Different Sulfation and Fucosylation Patterns.

Fucosylated chondroitin sulfate (fCS)-a glycosaminoglycan (GAG) found in sea cucumbers-has recently attracted much attention owing to its biological properties. In particular, a low molecular mass fCS polysaccharide has very recently been suggested as a strong candidate for the development of an antithrombotic drug that would be safer and more effective than heparin. To avoid the use of animal sourced drugs, here we present the chemical transformation of a microbial sourced unsulfated chondroitin polysaccharide into a small library of fucosylated (and sulfated) derivatives thereof. To this aim, a modular approach based on the different combination of only five reactions was employed, with an almost unprecedented polysaccharide branching by O-glycosylation as the key step. The library was differentiated for sulfation patterns and/or positions of the fucose branches, as confirmed by detailed 2D NMR spectroscopic analysis. These semi-synthetic polysaccharides will allow a wider and more accurate structure-activity relationship study with respect to those reported in literature to date.