Sub-toxic levels of Co(2+) are anti-inflammatory and protect cartilage from degradation caused by IL-1β

Double hits with bioactive nanozyme based on cobalt-doped nanoglass for acute and diabetic wound therapies through anti-inflammatory and pro-angiogenic functions

Regeneration of pathological wounds, such as diabetic ulcers, poses a significant challenge in clinical settings, despite the widespread use of drugs. To overcome clinical side effects and complications, drug-free therapeutics need to be developed to promote angiogenesis while overcoming inflammation to restore regenerative events. This study presents a novel bioactive nanozyme based on cobalt-doped nanoglass (namely, CoNZ), which exhibits high enzymatic/catalytic activity while releasing therapeutic ions. Cobalt oxide "Co3O4" tiny crystallites produced in situ through a chemical reaction with H2O2 within CoNZ nanoparticles play a crucial role in scavenging ROS. Results showed that CoNZ-treatment to full-thickness skin wounds in mice significantly accelerated the healing process, promoting neovascularization, matrix deposition, and epithelial lining while reducing pro-inflammatory signs. Notably, CoNZ was highly effective in treating pathological wounds (streptozotocin-induced diabetic wounds). Rapid scavenging of ROS by CoNZ and down-regulation of pro-inflammatory markers while up-regulating tissue healing signs with proliferative cells and activated angiogenic factors contributed to the observed healing events. In vitro experiments involving CoNZ-cultures with macrophages and endothelial cells exposed to high glucose and ROS-generating conditions further confirmed the effectiveness of CoNZ. CoNZ-promoted angiogenesis was attributed to the release of cobalt ions, as evidenced by the comparable effects of CoNZ-extracted ionic medium in enhancing endothelial migration and tubule formation via activated HIF-1α. Finally, we compared the in vivo efficacy of CoNZ with the clinically-available drug deferoxamine. Results demonstrated that CoNZ was as effective as the drug in closing the diabetic wound, indicating the potential of CoNZ as a novel drug-free therapeutic approach.

Association of urinary heavy metal combined exposure with periodontitis among US adults from NHANES 2011-2014

Some heavy metals are associated with periodontitis; whereas most of these associations have focused on individual metal, there are no specific studies on the effects of combined heavy metal exposure on periodontitis. We conducted an analysis on the association between urinary heavy metal exposure and periodontitis in participants aged 30 years and older using multiple logistic regression and Bayesian kernel machine regression (BKMR). This analysis was performed on data from the National Health and Nutrition Examination Survey from 2011 to 2014. The study found that using logistic regression, the 4th quartile of urinary lead and molybdenum and the 3rd quartile of urinary strontium were positively associated with periodontitis compared to the reference quartile after adjusting for covariates. Odds ratio (OR) with 95% confidence interval (CI) was 1.738 (1.069-2.826), 1.515 (1.025-2.239), and 1.498 (1.010-2.222), respectively. The 3rd and 4th quartiles of urinary cobalt were negatively associated with periodontitis, and their ORs and 95% CIs were 0.639 (0.438-0.934) and 0.571 (0.377-0.964), respectively. The BKMR model showed that urinary barium, lead, and molybdenum were positively associated with periodontitis in a range of concentrations and urinary cobalt, manganese, tin, and strontium were negatively correlated with periodontitis. Furthermore, the overall association between urinary heavy metals and periodontitis was positive. Our study provides evidence for an association between exposure to multiple urinary heavy metals and periodontitis. However, further longitudinal studies are needed to explore the specific mechanisms involved.

Fabricating the cartilage: recent achievements

This review aims to describe the most recent achievements and provide an insight into cartilage engineering and strategies to restore the cartilage defects. Here, we discuss cell types, biomaterials, and biochemical factors applied to form cartilage tissue equivalents and update the status of fabrication techniques, which are used at all stages of engineering the cartilage. The actualized concept to improve the cartilage tissue restoration is based on applying personalized products fabricated using a full cycle platform: a bioprinter, a bioink consisted of ECM-embedded autologous cell aggregates, and a bioreactor. Moreover, in situ platforms can help to skip some steps and enable adjusting the newly formed tissue in the place during the operation. Only some achievements described have passed first stages of clinical translation; nevertheless, the number of their preclinical and clinical trials is expected to grow in the nearest future.

Metal-Organic Framework Functionalized Bioceramic Scaffolds with Antioxidative Activity for Enhanced Osteochondral Regeneration

Osteoarthritis (OA) is a degenerative disease that often causes cartilage lesions and even osteochondral damage. Osteochondral defects induced by OA are accompanied by an inflammatory arthrosis microenvironment with overproduced reactive oxygen species (ROS), resulting in the exacerbation of defects and difficulty regenerating osteochondral tissues. Therefore, it is urgently needed to develop osteochondral scaffolds that can not only promote the integrated regeneration of cartilage and subchondral bone, but also possess ROS-scavenging ability to protect tissues from oxidative stress. Herein, zinc-cobalt bimetallic organic framework (Zn/Co-MOF) functionalized bioceramic scaffolds are designed for repairing osteochondral defects under OA environment. By functionalizing Zn/Co-MOF on the 3D-printed beta-tricalcium phosphate (β-TCP) scaffolds, the Zn/Co-MOF functionalized β-TCP (MOF-TCP) scaffolds with broad-spectrum ROS-scavenging ability are successfully developed. Benefiting from its catalytic active sites and degradation products, Zn/Co-MOF endows the scaffolds with excellent antioxidative and anti-inflammatory properties to protect cells from ROS invasion, as well as dual-bioactivities of simultaneously inducing osteogenic and chondrogenic differentiation in vitro. Furthermore, in vivo results confirm that MOF-TCP scaffolds accelerate the integrated regeneration of cartilage and subchondral bone in severe osteochondral defects. This study offers a promising strategy for treating defects induced by OA as well as other inflammatory diseases.

Primary Cilia: A Cellular Regulator of Articular Cartilage Degeneration

Osteoarthritis (OA) is the most common joint disease that can cause pain and disability in adults. The main pathological characteristic of OA is cartilage degeneration, which is caused by chondrocyte apoptosis, cartilage matrix degradation, and inflammatory factor destruction. The current treatment for patients with OA focuses on delaying its progression, such as oral anti-inflammatory analgesics or injection of sodium gluconate into the joint cavity. Primary cilia are an important structure involved in cellular signal transduction. Thus, they are very sensitive to mechanical and physicochemical stimuli. It is reported that the primary cilia may play an important role in the development of OA. Here, we review the correlation between the morphology (location, length, incidence, and orientation) of chondrocyte primary cilia and OA and summarize the relevant signaling pathways in chondrocytes that could regulate the OA process through primary cilia, including Hedgehog, Wnt, and inflammation-related signaling pathways. These data provide new ideas for OA treatment.

Primary Cilia as a Biomarker in Mesenchymal Stem Cells Senescence: Influencing Osteoblastic Differentiation Potency Associated with Hedgehog Signaling Regulation

Bone tissue engineering-based therapy for bone lesions requires the expansion of seeding cells, such as autologous mesenchymal stem cells (MSCs). A major obstacle to this process is the loss of the phenotype and differentiation capacity of MSCs subjected to passage. Recent studies have suggested that primary cilia, primordial organelles that transduce multiple signals, particularly hedgehog signals, play a role in senescence. Therefore, we explored the relationships among senescence, primary cilia, and hedgehog signaling in MSCs. Ageing of MSCs by expansion in vitro was accompanied by increased cell doubling time. The osteogenic capacity of aged MSCs at passage 4 was compromised compared to that of primary cells. P4 MSCs exhibited reductions in the frequency and length of primary cilia associated with decreased intensity of Arl13b staining on cilia. Senescence also resulted in downregulation of the expression of hedgehog components and CDKN2A. Suppression of ciliogenesis reduced the gene expression of both Gli1, a key molecule in the hedgehog signaling pathway and ALP, a marker of osteoblastic differentiation. This study demonstrated that the senescence of MSCs induced the loss of osteoblastic differentiation potency and inactivated hedgehog signaling associated with attenuated ciliogenesis, indicating that primary cilia play a mediating role in and are biomarkers of MSC senescence; thus, future antisenescence strategies involving manipulation of primary cilia could be developed.