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Purpose: To determine alterations of chondroitin sulfate (CS) that reflect cartilage damage in an experimental osteoarthritis (OA) model as well as in human OA samples., Materials and Methods: Rats were subjected to anterior cruciate ligament transection (ACLT; OA) or a sham procedure and sacrificed 14, 28, or 70 days after ACLT for histopathology and analysis of extracted CS. Cartilage samples from 14 patients undergoing hip or shoulder arthroplasty secondary to OA or fracture (control) were subjected to the same protocol. The CS content (µg/mg dry cartilage) after proteolysis was determined by densitometry, using agarose-gel electrophoresis. Molar mass (MM) and peak MM of CS were determined using high-performance size-exclusion chromatography (HPSEC)., Results: OA and sham joints at 70 d had 24 [22-24] and 3 [1-6] median histopathology scores, respectively (p < 0.001). Relative CS content (77.7 ± 8.3 µg/mg) was significantly increased in OA samples 70 d after ACLT, as compared to sham (53.5 ± 10.0 µg/mg). Peak MM of CS was higher in OA than in sham samples (P < 0.05). Similarly, CS content and peak MM were higher in cartilage from human OA patients, as compared to fracture samples, reproducing experimental data., Conclusion: Cartilage matrix from experimental and human OA samples has increased in the relative CS content. Increase in the peak MM distinguishes CS of the extracellular matrix of OA from normal cartilage.

We aimed to determine the characteristics that distinguish glycosaminoglycans (GAGs) from osteoarthritis (OA) and normal cartilage and from men and women. Cartilage samples from 30 patients subjected to total joint arthroplasty secondary to OA or fracture (control) were evaluated, and the GAG content (μg/mg dry cartilage) after proteolysis was determined by densitometry, using agarose-gel electrophoresis. Relative percentages of carbon (C), nitrogen (N), and sulfur (S) in GAGs were determined by elemental microanalysis, as well as the zeta potential. Seventeen samples (56.6%) were from patients >70 years old, with 20 (66.6%) from women, and most [20 (66.6%)] were from the hip. The GAG content was similar regardless of patients being >/≤ 70 years old with 96.5 ± 63.5 and 78.5 ± 38.5 μg/mg ( P = 0.1917), respectively. GAG content was higher in women as compared to men, with 89.5 ± 34.3 and 51.8 ± 13.3 μg/mg, respectively ( P = 0.0022), as well as in OA than fracture samples, with 98.4 ± 63.5 and 63.6 ± 19.6 μg/mg, respectively ( P = 0.0355). The GAG extracted from the cartilage of patients >70 years old had increase in N, and there were no gender differences regarding GAG elemental analysis. GAG from OA had a highly significant ( P = 0.0005) decrease in S% (1.79% ± 0.25%), as compared to fracture samples (2.3% ± 0.19%), with an associated and significant ( P = 0.0001) reduction of the zeta potential in the OA group. This is the first report of a reduced S content in GAG from OA patients, which is associated with a reduced zeta potential., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer JF is currently organizing a Research Topic with the author FR., (Copyright © 2021 Nunes, Girão, Cunha, Feitosa, Pinto and Rocha.)

Galactomannan extracted from Cassia fistula seed endosperm present little data related to the its structural characterization. This study reports the chemical characterization of the galactomannan from Cassia fistula (CF) and their oxidized derivatives. The extracted CF presented a yield of 26.5% (w/w) and the intrinsic viscosity [η] was 9.73 dL/g. 1D and 2D nuclear magnetic resonance spectroscopy (NMR) confirmed that the polysaccharide has a backbone of 4-linked β-D-mannose units, and contains galactose units as pending groups. These galactose units are linked to the central core through a (1→6) linkage and the galactomannan presented Man/Gal ratio of 3.1/1. The galactomannan from Cassia fistula presents low cytotoxicity in Vero cells with a CC 50  > 1000 μg/ml. The properties of CF resemble other commercially important galactomannans such as Locust bean gum. Three oxidized derivatives of CF were produced by periodate oxidation, which were carefully characterized by different structural techniques. It was observed that as the degree of oxidation increased, there was an increase in the Man/Gal ratio and a reduction in molar mass and viscosity. The polialdehyde produced may be explored as a versality material to react with amine group of the protein and amined polysaccharide to produce biomaterials., Competing Interests: Declaration of competing interest There are no conflicts of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Injection of Hylan G-F20 (HY) into joints may provoke local flares, which mechanisms may involve reaction to protein contaminants. We have previously developed a protein-free saline-soluble galactomannan derived from guar gum (GM) that displays both analgesia and chondroprotection in experimental osteoarthritis (OA). We now demonstrate that both GM and Hylan G-F20 (HY) promote mild synovitis with cytokine release after intra-articular injection., Methods: Mice received 100 μg/25 μL GM or HY or saline into the knees. Joint pain was evaluated using von Frey test; cell influx, interleukin (IL)-1, IL-6, and CXCL-1 (pg/mL) levels were assessed in joint lavage at 6 h. Synovia were excised for histopathology., Results: Neither GM nor HY after being given into mice knee joints induced pain albeit promoting mild cell influx into joint washings as well as mild synovitis at histology, with no damage to the underlying cartilage. HY but not GM promoted IL-1 release into mice joints. Both compounds induced IL-6 and CXCL-1 release., Conclusion: Intra-articular injection of HY or GM promote acute transient synovitis whilst not provoking detectable significant joint damage. Local administration of these polysaccharides induces acute intra-articular release of inflammatory cytokines, which may account for joint flares following viscosupplementation.

Xyloglucan was extracted from Tamarindus indica (T. indica) seeds from industrial residue, presenting a glucose, xylose and galactose ratio of 1.41:1.31:1 respectively, with aim of elaborating a film. A Central Compound Rotatable Design (CCRD) with Xyloglucan variables from T. indica (XylTi) and Glycerol (Gly) was used to prepare the film. The films were analyzed for water vapor permeability, thickness, opacity, moisture, tensile strength, elongation at break, Scanning Electron Microscopy, thermogravimetric analysis and FT-IR. A significant (p < 0.05) influence of XylTi and Gly was observed, resulting in an increase in moisture (24.09%), tensile strength (20.70 MPa) and elongation at break (50.84%), with an increase in the independent variables. The best results for this work proposal were the film with 4.5% XylTi/1.5% Gly (T3). The T3 film was used in evaluating the efficiency of the optimized film for packaging cut-up 'Sunrise Solo' papaya, and the results showed a higher mass loss than the PVC film and statistically the same for ethylene and carbon dioxide production. It is concluded that films made with xyloglucan from T. indica seeds obtained from the residue of the fruit pulp industry presented good physical characteristics, highlighting the T3 elaboration, and are viable for manufacturing food packaging., (Copyright © 2019. Published by Elsevier B.V.)