Uptake studies with chondrotropic 99mTc-chondroitin sulfate in articular cartilage. Implications for imaging osteoarthritis in the knee

Chondroitin sulfate-functionalized lipid nanoreservoirs: a novel cartilage-targeting approach for intra-articular delivery of cassic acid for osteoarthritis treatment

Novel intra-articular nanoreservoirs were implemented employing different cartilage targeting approaches to improve cartilage bioavailability of a chondroprotective drug, cassic acid (CA), for effective amelioration of cartilage deterioration off-targeting CA gastrointestinal disorders. Herein, we compared active cartilage-targeting approach via chondroitin sulfate (CHS) functionalization versus passive targeting using positively charged nanoparticles to target negatively charged cartilage matrix. Firstly, CA integrated nanoreservoirs (CA-NRs) were fabricated based on ionic conjugation between CA and cationic hydrophobic surface modifier octadecylamine (ODA) and were further functionalized with CHS to develop CHS-CA-NRs. Confocal laser microscope was used to visualize the accumulation of nanoparticles into the cartilage tissue. Both targeting approaches promoted CA local cartilage availability and prolonged its residence time. Compared to passive targeted CA-NRs, active targeted CHS-CA-NRs showed higher fluorescence signals in proximity to and inside chondrocytes which lasted for up to 21 days. In MIA-osteoarthritic rats, CHS-CA-NRs showed superior antiosteoarthritic activity, exhibiting highest cartilage repair compared to CA-NRs. Additionally, CHS-CA-NRs significantly inhibited OA inflammatory cytokine, degradation enzyme and oxidative stress and improved cartilage matrix biosynthesis. Conclusively, CHS-CA-NRs improved OA repair showing a superior efficacy for articular cartilage targeting with CHS which could be a potential advance for OA therapy.

[Chondroitin sulfate role in the complex rehabilitation of elderly people with chronic pain syndrome]

The article presents the data of the latest domestic and foreign original studies, the results of a number of meta-analyses, conclusions of randomized clinical trials (RCTs), and other scientific studies that prove the effectiveness and necessity of mandatory inclusion in the treatment of chronic pain syndrome of the stage of non-invasive non-pharmacological therapy. One of the promising areas of pharmacotherapy for degenerative-dystrophic joint lesions is the use of chondroprotectors (CP), in particular chondroitin sulfate (CS). According to new Clinical Recommendations of Ministry Health (MH) of the Russian Federation (RF) «Chronic pain in patients of elderly and senile age» (2020), according to which the purpose of CS is recommended for patients older than 60 years with joint pain and contraindications to non-steroidal anti-inflammatory drugs (NSAIDs) or senile asthenia for the purpose of pain relief and the prevention of exacerbations of pain. A high level of reliability and persuasiveness of the recommendations was noted (1A) of CS use. Most of the CS is available in the form of forms for oral use, the bioavailability of which, according to clinical studies, is 13-38% due to the destruction of the CS molecules in the gastrointestinal tract. Intramuscular (i/m) administration of the drug can increase the bioavailability of CS, which can not only increase the effectiveness of therapy, but also lead to a more rapid development of the symptomatic effect. In Russia available parenteral forms of CS (Chondroguard) pharmaceutical quality, efficacy has been proven in randomized clinical trial (RCT) MH RF. To relieve pain in the joints, it is recommended to use parenteral forms of CS (Chondroguard) at a dose of 100-200 mg per day, every other day, the total duration of the course of treatment is 25-30 injections.

A new look at back pain treatment in light of the latest ESCEO guidelines

Chronic pain (CP) is still one of the urgent problems of modern medicine. The paper provides a review of the main pharmacotherapeutic approaches from the standpoint of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) guidelines. When preparing this material, the authors have analyzed the publications available in the resources: PubMed, EMBASE, Cochrane, and еLIBRARY. The paper presents the main pathogenetic mechanisms of pain syndrome development in osteoarthritis (OA), including synovial inflammation and associated immune disorders. It considers the types of development of pain syndrome and the main prognostic outcomes according the mechanism of pain, providing a rationale for the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and/or chondroprotectors (CPs). In accordance with the ESCEO guidelines, it is noted that when starting OA therapy, CPs should be considered as the first step (in their long-term prescription and pharmaceutical quality), then NSAIDs should be added (topically), then (if ineffective) orally, by excluding patients with hip OA. It is known that the intramuscular administration of CPs (chondroitin sulfate (CS) in particular) can increase their bioavailability. The use of glucosamine sulfate (GS) is recommended for patients over 60 years of age. According to the recommendations of the 2019 ESCEO experts, CS and GS should be used as a disease-modifying OA drug from the first step and at all subsequent stages.

Preclinical evaluation of (99m)Tc labeled chondroitin sulfate for monitoring of cartilage degeneration in osteoarthritis

PURPOSE

In previous in-vitro and ex-vivo studies we proved the specific uptake of (99m)Tc radiolabeled chondroitin sulfate (CS) in human articular cartilage. As a logical next step for the clinical use for imaging osteoarthritis we investigated in-vivo uptake of (99m)TcCS in dogs.

PROCEDURES

The radiolabeling of CS Condrosulf (IBSA, Lugano, Switzerland) was performed using 25mg of CS and 20-40MBq/kg body weight of (99m)Tc by means of the tin method. In-vivo uptake of (99m)TcCS was evaluated in dogs (n=12, castrated males, 4-9years, with 15-51kg body weight). 6 healthy dogs served as controls and 6 with clinical and radiological signs of osteoarthritis in the carpal, elbow, and tarsal joint were examined. The tracer was i.v. injected into the external cephalic vein. The uptake was monitored after 2, 4, 6 and 24h in healthy and osteoarthritic dogs using a planar gamma camera by regional planar or whole body ventral and dorsal acquisition. For whole body scintigraphy animals were under general anesthesia, for planar under sedation only.

RESULTS

In healthy control dogs we did not detect any specific uptake of (99m)TcCS in the cartilage. In contrast, in the diseased dogs suffering from osteoarthritis a significant, specific, persistent uptake between 4 and 6h in tarsal, carpal and cubital joints was documented. Median target (joint) to background (mid antebrachium) ratio (T/B) in the OA joints after 4, 6, and 24h was significantly higher than in healthy controls. Target to background ratio using soft tissue as a background (T/S) a similar significantly higher than in healthy controls. In all osteoarthritic joints we found a significant positive correlation (r=0.8, n=20) between grade of disease (I-III) and T/B. When matching radiographic (X ray) changes in osteoarthritic joints (grade II and III) we found also a maximal uptake of (99m)TcCS at the specific anatomical site of highest cartilage degeneration. None of the dogs experienced any side effects.

CONCLUSION

These results suggest that (99m)TcCS might become a promising diagnostic tool for imaging osteoarthritis. More extensive and detailed examinations are required, however, before extending this methodology for application in humans.

A pharmacoproteomic study confirms the synergistic effect of chondroitin sulfate and glucosamine

Osteoarthritis (OA) is the most common age-related rheumatic disease. Chondrocytes play a primary role in mediating cartilage destruction and extracellular matrix (ECM) breakdown, which are main features of the OA joint. Quantitative proteomics technologies are demonstrating a very interesting power for studying the molecular effects of some drugs currently used to treat OA patients, such as chondroitin sulfate (CS) and glucosamine (GlcN). In this work, we employed the iTRAQ (isobaric tags for relative and absolute quantitation) technique to assess the effect of CS and GlcN, both alone and in combination, in modifying cartilage ECM metabolism by the analysis of OA chondrocytes secretome. 186 different proteins secreted by the treated OA chondrocytes were identified. 36 of them presented statistically significant differences (p ≤ 0.05) between untreated and treated samples: 32 were increased and 4 decreased. The synergistic chondroprotective effect of CS and GlcN, firstly reported by our group at the intracellular level, is now demonstrated also at the extracellular level.