Extraction and characterization of valuable compounds from chicken sternal cartilage: Type II collagen and chondroitin sulfate.

Type II collagen (Col II) and chondroitin sulfate (CS) are the main macromolecules in the extracellular matrix. This study investigated the characteristics of Col II and CS obtained from chicken sternal cartilage (CSC) via enzymatic hydrolysis for various treatment times. For Col II and CS, the highest efficiency of enzymatic hydrolysis was achieved after 24 and 6 h of treatment, respectively. The average molecular weights were α1 chain-130 kDa, ß chain-270 kDa for Col II, and 80.27 kDa for CS. Fourier transform infrared spectroscopy revealed that the Col II samples maintained their triple-helical structure and that the predominant type of CS was chondroitin-4-sulfate. Scanning electron microscopy revealed that the Col II and CS samples possessed fibrillar and clustered structures, respectively. This study suggests that collagen and CS obtained from CSC can be used as promising molecules for application in food and pharmaceutical industries.

In situ study on articular cartilage degeneration in simulated microgravity by HOF-ATR-FTIR spectroscopy.

Fourier transform infrared spectroscopy (FTIRS) can provide rich information on the composition and content of samples, enabling the detection of subtle changes in tissue composition and structure. This study represents the first application of FTIRS to investigate cartilage under microgravity. Simulated microgravity cartilage model was firstly established by tail-suspension (TS) for 7, 14 and 21 days, which would be compared to control samples. A self-developed hollow optical fiber attenuated total reflection (HOF-ATR) probe coupled with a FTIR spectrometer was used for the spectral acquisition of cartilage samples in situ, and one-way analysis of variance (ANOVA) was employed to analyze the changes in the contents of cartilage matrix at different stages. The results indicate that cartilage degenerates in microgravity, the collagen content gradually decreases with the TS time, and the structure of collagen fibers changes. The trends of proteoglycan content and collagen integrity show an initial decrease followed by an increase, ultimately significantly decreasing. The findings provide the basis for the cartilage degeneration in microgravity with TS time, which must be of real significance for space science and health detection.

Efficiently directing differentiation and homing of mesenchymal stem cells to boost cartilage repair in osteoarthritis via a nanoparticle and peptide dual-engineering strategy.

Mesenchymal stem cells (MSCs) are expected to be useful therapeutics in osteoarthritis (OA), the most common joint disorder characterized by cartilage degradation. However, evidence is limited with regard to cartilage repair in clinical trials because of the uncontrolled differentiation and weak cartilage-targeting ability of MSCs after injection. To overcome these drawbacks, here we synthesized CuO@MSN nanoparticles (NPs) to deliver Sox9 plasmid DNA (favoring chondrogenesis) and recombinant protein Bmp7 (inhibiting hypertrophy). After taking up CuO@MSN/Sox9/Bmp7 (CSB NPs), the expressions of chondrogenic markers were enhanced while hypertrophic markers were decreased in response to these CSB-engineered MSCs. Moreover, a cartilage-targeted peptide (designated as peptide W) was conjugated onto the surface of MSCs via a click chemistry reaction, thereby prolonging the residence time of MSCs in both the knee joint cavity of mice and human-derived cartilage. In a surgery-induced OA mouse model, the NP and peptide dual-modified W-CSB-MSCs showed an enhancing therapeutic effect on cartilage repair in knee joints compared with other engineered MSCs after intra-articular injection. Most importantly, W-CSB-MSCs accelerated cartilage regeneration in damaged cartilage explants derived from OA patients. Thus, this new peptide and NPs dual engineering strategy shows potential for clinical applications to boost cartilage repair in OA using MSC therapy.

Medial patellar luxation induces cartilage erosion in dogs: a retrospective study of prevalence and risk factors.

OBJECTIVE: To explain the relationship between cartilage erosion and medial patellar luxation (MPL) and to identify risk factors in dogs. METHODS: A retrospective review was conducted on 90 dogs (103 stifles) surgically treated for MPL between January 2006 and March 2024. Data collected included signalment, side of operated stifle, patellar luxation grade, symptom duration, and lameness score. Cartilage erosion was evaluated for extent and location on the patella and femoral trochlea. Statistical analyses were conducted to identify risk factors. RESULTS: The prevalence of cartilage erosion of the patella and femoral trochlea was 47.6% (49/103) and 54.4% (56/103), respectively, increasing with a higher grade of patellar luxation. Lesions were most prevalent in the distolateral patella and proximomedial trochlea, with generalized lesions more prevalent in grade IV. The extent of both lesions was significantly associated with age, patellar luxation grade, and symptom duration, while body weight significantly correlated only with the cartilage erosion of the patella. No significant correlation was observed with sex, side of operated stifle, or lameness score. CONCLUSIONS: Many patients with MPL exhibited cartilage erosion in the patellofemoral joint, likely due to biomechanical mechanisms. Surgery can be indicated for patients with MPL, as it may prevent cartilage erosion while improving patellofemoral alignment and gait. When selecting surgical candidates, it is important to consider risk factors, such as patellar luxation grade, body weight, age, and symptom duration. CLINICAL RELEVANCE: Early surgical treatment is recommended, especially for dogs with higher body weight and higher grade of MPL, to prevent cartilage erosion and secondary osteoarthritis.

Identification of candidate genes and chemicals associated with osteonecrosis of femoral head by multiomics studies and chemical-gene interaction analysis.

Objectives: In-depth understanding of osteonecrosis of femoral head (ONFH) has revealed that degeneration of the hip cartilage plays a crucial role in ONFH progression. However, the underlying molecular mechanisms and susceptibility to environmental factors in hip cartilage that contribute to ONFH progression remain elusive. Methods: We conducted a multiomics study and chemical-gene interaction analysis of hip cartilage in ONFH. The differentially expressed genes (DEGs) involved in ONFH progression were identified in paired hip cartilage samples from 36 patients by combining genome-wide DNA methylation profiling, gene expression profiling, and quantitative proteomics. Gene functional enrichment and pathway analyses were performed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Functional links between proteins were discovered through protein-protein interaction (PPI) networks. The ONFH-associated chemicals were identified by integrating the DEGs with the chemical-gene interaction sets in the Comparative Toxicogenomics Database (CTD). Finally, the DEGs, including MMP13 and CHI3L1, were validated via quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC). Results: Twenty-two DEGs were identified across all three omics levels in ONFH cartilage, 16 of which were upregulated and six of which were downregulated. The collagen-containing extracellular matrix (ECM), ECM structural constituents, response to amino acids, the relaxin signaling pathway, and protein digestion and absorption were found to be primarily involved in cartilage degeneration in ONFH. Moreover, ten major ONFH-associated chemicals were identified, including, benzo(a)pyrene, valproic acid, and bisphenol A. Conclusion: Overall, our study identified several candidate genes, pathways, and chemicals associated with cartilage degeneration in ONFH, providing novel clues into the etiology and biological processes of ONFH progression.

A novel mesenchymal stem cell-targeting dual-miRNA delivery system based on aptamer-functionalized tetrahedral framework nucleic acids: Application to endogenous regeneration of articular cartilage.

Articular cartilage injury (ACI) remains one of the key challenges in regenerative medicine, as current treatment strategies do not result in ideal regeneration of hyaline-like cartilage. Enhancing endogenous repair via microRNAs (miRNAs) shows promise as a regenerative therapy. miRNA-140 and miRNA-455 are two key and promising candidates for regulating the chondrogenic differentiation of mesenchymal stem cells (MSCs). In this study, we innovatively synthesized a multifunctional tetrahedral framework in which a nucleic acid (tFNA)-based targeting miRNA codelivery system, named A-T-M, was used. With tFNAs as vehicles, miR-140 and miR-455 were connected to and modified on tFNAs, while Apt19S (a DNA aptamer targeting MSCs) was directly integrated into the nanocomplex. The relevant results showed that A-T-M efficiently delivered miR-140 and miR-455 into MSCs and subsequently regulated MSC chondrogenic differentiation through corresponding mechanisms. Interestingly, a synergistic effect between miR-140 and miR-455 was revealed. Furthermore, A-T-M successfully enhanced the endogenous repair capacity of articular cartilage in vivo and effectively inhibited hypertrophic chondrocyte formation. A-T-M provides a new perspective and strategy for the regeneration of articular cartilage, showing strong clinical application value in the future treatment of ACI.

ISG15 is involved in chondrogenic differentiation through activation of IFN-γ signaling.

Interferon-gamma (IFN-γ) was found to increase in the synovial fluid of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). However, few studies have been conducted to elucidate the role of IFN-γ in cartilage metabolism and regeneration. In this study, we investigated whether cartilage regeneration is driven by interferon-stimulated gene 15 (ISG15) under the control of IFN-γ. IFN-γ significantly increased ITS-induced chondrogenic differentiation of ATDC5 cells. Knockdown of IFN-γ receptor (IFN-γR) inhibited IFN-γ-induced chondrogenic differentiation and reduced ACAN and Col II expression. In addition, ISG15 expression was highly elevated in response to IFN-γ, whereas its expression was downregulated by knockdown of IFN-γR, indicating that ISG15 is closely related to IFN-γ signaling. Furthermore, chondrogenic differentiation and expression of ACAN and Col II were significantly reduced following knockdown of ISG15 in ATDC5 cells despite the presence of IFN-γ. ISGylation of cellular proteins found in chondrogenic differentiated cells was related to activation of IFN-γ signaling. In addition, ISG15/ISGylation was significantly observed in the regenerated cartilage tissue 7 days after FTCI of young mice compared with sham control. Our findings showed that upregulation of ISG15 and/or ISGylation of cellular proteins may play a critical role in cartilage regeneration through activation of IFN-γ signaling.

Sarcopenia Is Associated with Neoplasm of Bone and Articular Cartilage: Findings from Mendelian Randomized Study.

Exploring the causal relationship between sarcopenia and neoplasm of bone and articular cartilage (NBAC) by bidirectional Mendelian randomization (MR). Genome-wide association study (GWAS) data on sarcopenia-associated traits including appendicular lean mass, low handgrip strength (including criteria from the European Working Group on Sarcopenia in Older People and the Foundation for the National Institutes of Health), and usual walking speeds were obtained from the UK Biobank. GWAS data for NBAC (benign and malignant) were provided by the Finnish Genetic Database. Three different methods of MR analysis, including inverse-variance weighted, Mendelian randomized Egger regression, and weighted median methods, were utilized. MR analysis showed that high appendicular lean mass was positively associated with the risk of developing benign NBAC (odds ratio and 95% confidence interval = 1.236 (1.026,1.489), p = 0.025). At the same time, there is no statistically significant association was found between traits related to sarcopenia and malignant neoplasm of bone and articular cartilage. There was also no reverse causal correlation between NBAC and traits related to sarcopenia. In European populations, better appendicular lean body mass is positively associated with the risk of benign neoplasm of bone and articular cartilage, representing the possibility that sarcopenia may be a protective factor against neoplasm of bone and articular cartilage.

Cancer of the Larynx-20-Year Comparative Survival and Mortality Analysis by Age, Sex, Race, Stage, Grade, Cohort Entry Time-Period, Disease Duration and ICD-O-3 Topographic Primary Sites-Codes C32.0-9: A Systematic Review of 43,103 Cases for Diagnosis Years 1975-2017: (NCI SEER*Stat 8.3.9).

BACKGROUND: .-Laryngeal malignancy, "voice box" cancer, is uncommon with 12,620 estimated new cases and 3770 deaths in the United States in 2021,1 and represents only 6.2% of all respiratory system malignancies. The most significant risk factors are alcohol and tobacco consumption. Almost all cases (98%) of laryngeal cancer arise in the squamous epithelium, and in this analysis more than 75% are of well-or-moderately differentiated histopathology (Grades I&II). Local stage cancer (SEER Historic Staging) was more common than regional and distant stages combined (55.3% vs 44.7%). Tumors may arise above, below or at the level of the vocal folds and are described as supraglottic (encompassing the epiglottis, false vocal cords, ventricles, aryepiglottic fold and arytenoids), the glottis (encompassing the true vocal cords and the anterior and posterior commissures), and the subglottic region. In the National Cancer Institute's Surveillance, Epidemiology, End-Results (NCI-SEER) Data Research, 9 Registries, Nov 2019 Sub (1975-2017),2 laryngeal cancer occurred more commonly in men than in women, 80.7% vs 19.3%, respectively with a 4.2 to 1 ratio. Additionally, there are racial disparities with African Americans presenting at a younger age and having a higher incidence and mortality than Caucasians. In the 1975-2017 period, overall median patient age was 64.4 years with White Americans-64.8 years and Black Americans-61.5 years. Unfortunately, the 5-year relative survival rate has declined 4%, and excess death rate has risen 13% since 1975 with overall incidence declining.As a consequence, observed median survival is approximately 6.5-years for the total study-period pinpointing the need for further specialty research. This study follows the World Health Organization International Classification of Diseases for Oncology-3rd Edition (ICD-O-3)3 topographical identification, coding, labeling and listing of 43,103 patient-cases accessible for analysis in the United States National Cancer Institute's Surveillance, Epidemiology and End Results program (NCI SEER Research Data, 9 Registries, 1975-2017). These are located in 6 primary anatomical sites: C32.0-Glottis, C32.1-Supraglottis, C32.2-Subglottis, C32.3-Laryngeal cartilage, C32.8-Overlapping lesion of larynx, C32.9-Larynx, NOS. OBJECTIVES: .-To update short- and long-term mortality and survival indices, and identify changing risk patterns for laryngeal cancer patients in a retrospective US population-based analysis, 1975-2017, using prognostic data stratified by ICD-O-3 Primary Site, age, sex, race, stage, histologic grade, two cohort entry time-periods (1975-1996 to 1997-2017), and disease duration to 20-years. METHODS: .-SEER*Stat v8.3.94 software (built March 12, 2021) was used to access SEER Research Data, 9 Registries, Nov. 2019 submission (1975-2017). For displaying risk, general methods and standard double decrement life table methodologies for converting and displaying ICD-O-3 coded laryngeal cancer primary site annual data to aggregate average annual mortality and survival units in durational-intervals of 0-1, 1-2, 2-5, 0-5, 5-10, 10-15, and 15-20 years were employed. The reader is referred to the "Registrar Staging Assistant (SEER*RSA)" for local-regional-distant Extent of Disease (EOD) sources used in the development of staging descriptions, and Summary Stage 2018 Coding Manual v2.0 released September 1, 2020. Cancer staging & grading procedural explanations, statistical significance and 95% confidence levels5 are described in previous Journal of Insurance Medicine articles6,7 and other publications.8,9 Poisson confidence intervals at the 95% level based on the number of observed deaths are used in this study but not displayed here to conserve space on the mortality tables. Excluded were all death certificate only and those alive with no survival time. RESULTS: .-Total SEER annual age-adjusted incidence rates from 1980 to 2017 have diminished from 5.25 patient-cases/100,000/year to 2.59/100,000 per year, and in the same period annual age-adjusted US death rates declined from 1.61 deaths/100.000/year to 0.91 deaths/100,000/year (Ref. 10, CSR Tables 12.5-6), However, in the 0-5-year disease durational interval for all staged cases in both cohort time-periods (Table 5), excess death rates (EDR) rose from 80 per 1000 persons per year in the 1975-96 cohort, to 89 per 1000 persons per year in the 1997-17 cohort, (a 10% rise in excess mortality in 42 years). Further, in the 5-10-year disease durational interval, EDR rose from 39 per 1000 persons per year to 45 per 1000 persons per year with corresponding cohort declines in cumulative survival ratios (SR), and overall declines in median observed and relative survival times in the later cohort (not shown). The epidemiologic burden of malignancy is >4-fold higher in males and increases in parallel with aging, peaking after 65 years. The most significant risk factors for laryngeal cancer are tobacco and alcohol consumption. CONCLUSION: .-Although annual incidence and mortality rates from 1980 to 2017 have diminished, there is no concomitant improvement in larynx cancer survival (SR) and mortality (EDR) indices, with rising mortality and diminishing survival in all staged cases at 5-years disease duration between the 1975-96 and 1997-2017 analytic cohorts. Larynx cancer remains a burdensome clinical, social, and public health challenge.

The Tricellufuse Technique for Closing Nasal Septal Perforations.

Objective: Nasal septal perforation (NSP) is a structural anomaly that affects the mucosa, cartilage, and bone of the nasal septum, often stemming from septoplasty as the primary cause. Spontaneous healing of a perforated septum is rare, and typically the healing process is observed until it is determined that the condition is stable and no longer deteriorating, at which point surgical intervention is considered. Numerous surgical techniques have been proposed for NSP repair. This study introduces a novel approach incorporating a fascia lata graft with fat tissue and diced septal cartilage to reconstruct medium-sized NSP. Methods: The researchers conducted a retrospective analysis involving 22 patients who underwent repair for NSP from January 2021 to January 2023. Grafts were obtained, and the perforation was addressed using an open rhinoplasty technique, followed by the insertion and suturing of the graft. Results: The mean size of the septal perforations was 12 mm horizontally and 13 mm vertically. All patients with NSPs were chosen as medium size (within 0.5-2 cm). The mean follow-up period was 12 months. Complete closure of NSP was achieved in 19 out of 22 patients (86.3%). Among the cases, 15 were male (68%), and the ages ranged from 25 to 45 years with a mean of 35. Eight cases (36%) were smokers. After 12 months postoperatively, closure was not achieved in 3 medium-sized NSPs due to smoking. . The analysis revealed that the failure rate in the smoker group was statistically significant (P = .036). Conclusion: The TriCelluFuse technique, combining fascia lata, fat tissue, and diced septal cartilage, is a secure and reliable method for closing NSPs. It has a significant success rate and should be considered a viable option for individuals with NSPs.

Quantitative susceptibility and T1 ρ mapping of knee articular cartilage at 3T.

T1 ρ and Quantitative Susceptibility Mapping (QSM) are evolving as substrates for quantifying the progressive nature of knee osteoarthritis. Objective: To evaluate the effects of spin lock time combinations on depth-dependent T1 ρ estimation, in adjunct to QSM, and characterize the degree of shared variance in QSM and T1 ρ for the quantitative measurement of articular cartilage. Design: Twenty healthy participants (10 â€‹M/10F, 22.2 â€‹± â€‹3.4 years) underwent bilateral knee MRI using T1 ρ MAPPS sequences with varying TSLs ([0-120] ms), along with a 3D spoiled gradient echo for QSM. Five total TSL combinations were used for T1 ρ computation, and direct depth-based comparison. Depth-wide variance was assessed in comparison to QSM as a basis to assess for depth-specific variation in T1 ρ computations across healthy cartilage. Results: Longer T1 ρ relaxation times were observed for TSL combinations with higher spin lock times. Depth-specific differences were documented for both QSM and T1 ρ , with most change found at ∼60% depth of the cartilage, relative to the surface. Direct squared linear correlation revealed that most T1 ρ TSL combinations can explain over 30% of the variability in QSM, suggesting inherent shared sensitivity to cartilage microstructure. Conclusions: T1 ρ mapping is subjective to the spin lock time combinations used for computation of relaxation times. When paired with QSM, both similarities and differences in signal sensitivity may be complementary to capture depth-wide changes in articular cartilage.

Melatonin Alleviates Osteoarthritis by Regulating NADPH Oxidase 4-Induced Ferroptosis and Mitigating Mitochondrial Dysfunction.

Recent evidence indicates that the damaged regions in osteoarthritis are accompanied by the accumulation of iron ions. Ferroptosis, as an iron-dependent form of cell death, holds significant implications in osteoarthritis. Melatonin, a natural product with strong scavenging abilities against reactive oxygen species and lipid peroxidation, plays a crucial role in the treatment of osteoarthritis. This study aims to demonstrate the existence of ferroptosis in osteoarthritis and explore the specific mechanism of melatonin in suppressing ferroptosis and alleviating osteoarthritis. Our findings reveal that melatonin reverses inflammation-induced oxidative stress and lipid peroxidation while promoting the expression of extracellular matrix components in chondrocytes, safeguarding the cells. Our research has revealed that NADPH oxidase 4 (NOX4) serves as a crucial molecule in the ferroptosis process of osteoarthritis. Specifically, NOX4 is located on mitochondria in chondrocytes, which can induce disorders in mitochondrial energy metabolism and dysfunction, thereby intensifying oxidative stress and lipid peroxidation. LC-MS analysis further uncovered that GRP78 is a downstream binding protein of NOX4. NOX4 induces ferroptosis by weakening GRP78's protective effect on GPX4 and reducing its expression. Melatonin can inhibit the upregulation of NOX4 on mitochondria and mitigate mitochondrial dysfunction, effectively suppressing ferroptosis and alleviating osteoarthritis. This suggests that melatonin therapy represents a promising new approach for the treatment of osteoarthritis.

Evaluation of an automated laminar cartilage T2 relaxation time analysis method in an early osteoarthritis model.

OBJECTIVE: A fully automated laminar cartilage composition (MRI-based T2) analysis method was technically and clinically validated by comparing radiographically normal knees with (CL-JSN) and without contra-lateral joint space narrowing or other signs of radiographic osteoarthritis (OA, CL-noROA). MATERIALS AND METHODS: 2D U-Nets were trained from manually segmented femorotibial cartilages (n = 72) from all 7 echoes (AllE), or from the 1st echo only (1stE) of multi-echo-spin-echo (MESE) MRIs acquired by the Osteoarthritis Initiative (OAI). Because of its greater accuracy, only the AllE U-Net was then applied to knees from the OAI healthy reference cohort (n = 10), CL-JSN (n = 39), and (1:1) matched CL-noROA knees (n = 39) that all had manual expert segmentation, and to 982 non-matched CL-noROA knees without expert segmentation. RESULTS: The agreement (Dice similarity coefficient) between automated vs. manual expert cartilage segmentation was between 0.82 ± 0.05/0.79 ± 0.06 (AllE/1stE) and 0.88 ± 0.03/0.88 ± 0.03 (AllE/1stE) across femorotibial cartilage plates. The deviation between automated vs. manually derived laminar T2 reached up to - 2.2 ± 2.6 ms/ + 4.1 ± 10.2 ms (AllE/1stE). The AllE U-Net showed a similar sensitivity to cross-sectional laminar T2 differences between CL-JSN and CL-noROA knees in the matched (Cohen's D ≤ 0.54) and the non-matched (D ≤ 0.54) comparison as the matched manual analyses (D ≤ 0.48). Longitudinally, the AllE U-Net also showed a similar sensitivity to CL-JSN vs. CS-noROA differences in the matched (D ≤ 0.51) and the non-matched (D ≤ 0.43) comparison as matched manual analyses (D ≤ 0.41). CONCLUSION: The fully automated T2 analysis showed a high agreement, acceptable accuracy, and similar sensitivity to cross-sectional and longitudinal laminar T2 differences in an early OA model, compared with manual expert analysis. TRIAL REGISTRATION: Clinicaltrials.gov identification: NCT00080171.

Extraskeletal Chondromatosis in a 30-Year-Old Patient: A Rare Case Report.

The term chondroma refers to a slow-growing benign tumor. When the tumor arises from the medullary cavity, it is referred to as enchondroma, which is a very common bone tumor. However, if it arises from soft tissues, which is extremely rare, it is referred to as soft tissue chondroma or extraskeletal chondroma. Extraskeletal chondromas are uncommon; benign soft tissue tumors that mostly originate from hyaline cartilage are unrelated to the periosteum, tendon, or bone. The most common sites include fingers and toes. The frequent presentation is a slow-growing, firm, painless, and occasionally tender soft tissue mass. Morphologically, it exhibits lobular structures of hyaline cartilage, and hence it becomes difficult to differentiate it from low-grade chondrosarcoma, so the alarming sign of differentiation becomes a must. Recurrence is possible if it is incompletely removed. Complete removal with the capsule is a must to avoid recurrence. Immunohistochemistry remains the cornerstone for a definite diagnosis when S100 protein and vimentin show positivity for tumor cells and the proliferation index (Ki67%) is low. In this study, we present a very uncommon case of a 30-year-old patient with soft tissue chondromatosis of the palmer aspect of the index finger and palm.

3D printing of recombinant collagen/chitosan methacrylate/nanoclay hydrogels loaded with Kartogenin nanoparticles for cartilage regeneration.

Cartilage defects are frequently caused by trauma, illness and degradation of the cartilage. If these defects are not sufficiently treated, the joints will degrade irreversibly, possibly resulting in disability. Articular cartilage lacks blood vessels and nerves and is unable to regenerate itself, so the repair of cartilage defects is extremely challenging in clinical treatment. Tissue engineering technology is an emerging technology in cartilage repair and cartilage regeneration. 3D-printed hydrogels show great potential in cartilage tissue engineering for the fabrication of 3D cell culture scaffolds to mimic extracellular matrix. In this study, we construct a 3D-printed hydrogel loaded with nanoparticles by electrostatic interaction and photo cross-linking for the regeneration of cartilage, which has adaptable and drug-continuous release behavior. A photopolymerizable bioink was prepared using recombinant collagen, chitosan, nanoclay Laponite-XLG and nanoparticles loaded with Kartogenin (KGN). This bioink was added with KGN, a small molecule drug that promotes cartilage differentiation, and as a result, the 3D-printed CF/CM/3%LAP/KGN scaffolds obtained by extrusion printing is expected to be used for cartilage repair. It was shown that the 3D-printed scaffolds had good cytocompatibility for human bone marrow mesenchymal stem cells (hBMSCs) and exhibited excellent antimicrobial properties, the continuous release of KGN in the scaffold induced the hBMSCs differentiation into chondrocytes, which significantly enhanced the expression of collagen II and glycosaminoglycan. In vivo studies have shown that implantation of KGN-loaded scaffolds into cartilage-injured tissues promoted cartilage tissue regeneration. This study demonstrated that 3D-printed CF/CM/3%LAP/KGN scaffolds can be used for cartilage repair, which is expected to lead to new healing opportunities for cartilage injury-based diseases.

Semi-synthetic chondroitin sulfate CS-semi5 upregulates miR-122-5p, conferring a therapeutic effect on osteoarthritis via the p38/MMP13 pathway.

Osteoarthritis (OA) is an aging-associated disease characterized by joint stiffness pain and destroyed articular cartilage. Traditional treatments for OA are limited to alleviating various OA symptoms. There is a lack of drugs available in clinical practice that can truly repair cartilage damage. Here, we developed the chondroitin sulfate analog CS-semi5, semi-synthesized from chondroitin sulfate A. In vivo, CS-semi5 alleviated inflammation, provided analgesic effects, and protected cartilage in the modified Hulth OA rat model and papain-induced OA rat model. A bioinformatics analysis was performed on samples from OA patients and an exosome analysis on papain-induced OA rats, revealing miR-122-5p as the key regulator associated with CS-semi5 in OA treatment. Binding prediction revealed that miR-122-5p acted on the 3'-untranslated region of p38 mitogen-activated protein kinase, which was related to MMP13 regulation. Subsequent in vitro experiments revealed that CS-semi5 effectively reduced cartilage degeneration and maintained matrix homeostasis by inhibiting matrix breakdown through the miR-122-5p/p38/MMP13 axis, which was further validated in the articular cartilage of OA rats. This is the first study to investigate the semi-synthesized chondroitin sulfate CS-semi5, revealing its cartilage-protecting, anti-inflammatory, and analgesic properties that show promising therapeutic effects in OA via the miR-122-5p/p38/MMP13 pathway.

Effect of load reduction on the calcification of rat tibial tuberosity: Focus on calcification factors and chondrocyte mechanosensors.

The tibial tuberosity has a superficial patellar tendon-embedded portion and a deep uncalcified cartilage portion. Suppressed calcification of the tibial tuberosity leads to Osgood-Schlatter disease. The tibial tuberosity calcifies with age; load reduction degrades the cartilage matrix and promotes calcification, suggesting that reduced mechanical stimulation of the tibial tuberosity promotes calcification. However, this is yet to be clarified. Therefore, in this study, we aimed to investigate the effects of mechanical stimulation reduction on the tibial tuberosity tissue structure and calcification mechanism. Specifically, we examined the effect of load reduction on tibial tuberosity calcification in 20 male 7-week-old Wistar rats classified into two groups: hind-limb suspension (HS, n = 10) and control (CO, n = 10). We observed superficial and deep tibial tuberosities in both groups. The tibial tuberosity in the HS group had narrower areas of deep portions than did those in the CO group (p = 0.000539), and immature bone tissue and cartilage tissue were observed in the HS group. Enpp1 expression did not significantly differ between the groups (p = 0.804). In contrast, Alpl (p = 0.001) and Mmp3 (p = 0.006) expression increased whereas Timp3 expression decreased (p = 0.002) in the HS group. Thus, these results showed a maturing of bone ossification, and this gene expression trend was similar to that observed in a murine join instability model of osteoarthritis with articular cartilage calcification and ossification. The HS tibial tuberosity also showed immature bone tissue. In conclusion, reduced mechanical stimulation caused tibial tuberosity calcification and pathological changes. These findings highlight the importance of optimal exercise to avoid premature pathological structural changes in bones and joints.

Microbiome and Femoral Cartilage Thickness in Knee Osteoarthritis: Is There a Link?

OBJECTIVE: To assess the relation between microbiome and lipopolysaccharide (LPS), in the blood and synovial fluid (SF) with femoral cartilage thickness (FCT) measured by ultrasound (US) in knee osteoarthritis (KOA) patients. METHODS: This cross-sectional study included 40 primary KOA patients recruited between September 2022 and June 2023. Age, gender, and body mass index (BMI) were recorded. Patients underwent full clinical examination, standing plain x-ray of the knee joint and knee US examination to measure medial, intercondylar, and lateral FCT. Microbiomes (specific bacterial phyla) were detected by real-time polymerase chain reaction and LPS levels were measured by enzyme-linked immunosorbent assay kit in the patients' serum and SF. RESULTS: The patient's age ranged from 43 to 72 years. Most patients were females (72.5%), with a mean BMI of 35.8 ± 6.21 kg/m2. The mean medial, intercondylar, and lateral FCT were less than cut-off values. All 40 (100%) patients showed positive bacterial deoxyribonucleic acid (16S ribosomal RNA) in both blood and SF samples. Firmicutes was the most abundant in patients' blood (48.49%) and SF (63.59%). The mean serum LPS level was significantly higher compared to mean SF LPS (t =4.702, P < 0.001). There was a statistically significant negative correlation between lateral FCT and Firmicutes relative abundance in both patients' blood and SF. CONCLUSION: Microbiome and LPS are present in the blood and SF of primary KOA patients. Microbiome (Firmicutes) was associated with decreased lateral FCT. This might provide a potential link between both systemic and local microbiomes and cartilage affection in KOA patients.

Cell-based therapies have disease-modifying effects on osteoarthritis in animal models: A systematic review by the ESSKA Orthobiologic Initiative. Part 3: Umbilical cord, placenta, and other sources for cell-based injectable therapies.

PURPOSE: This systematic review aimed to investigate in animal models the presence of disease-modifying effects driven by non-bone marrow-derived and non-adipose-derived products, with a particular focus on umbilical cord and placenta-derived cell-based therapies for the intra-articular injective treatment of osteoarthritis (OA). METHODS: A systematic review was performed on three electronic databases (PubMed, Web of Science and Embase) according to PRISMA guidelines. The results were synthesised to investigate disease-modifying effects in preclinical animal studies comparing injectable umbilical cord, placenta, and other sources-derived products with OA controls. The risk of bias was assessed using the SYRCLE tool. RESULTS: A total of 80 studies were included (2314 animals). Cell therapies were most commonly obtained from the umbilical cord in 33 studies and placenta/amniotic tissue in 18. Cell products were xenogeneic in 61 studies and allogeneic in the remaining 19 studies. Overall, 25/27 (92.6%) of studies on umbilical cord-derived products documented better results compared to OA controls in at least one of the following outcomes: macroscopic, histological and/or immunohistochemical findings, with 19/22 of studies (83.4%) show positive results at the cartilage level and 4/6 of studies (66.7%) at the synovial level. Placenta-derived injectable products documented positive results in 13/16 (81.3%) of the studies, 12/15 (80.0%) at the cartilage level, and 2/4 (50.0%) at the synovial level, but 2/16 studies (12.5%) found overall worse results than OA controls. Other sources (embryonic, synovial, peripheral blood, dental pulp, cartilage, meniscus and muscle-derived products) were investigated in fewer preclinical studies. The risk of bias was low in 42% of items, unclear in 49%, and high in 9% of items. CONCLUSION: Interest in cell-based injectable therapies for OA treatment is soaring, particularly for alternatives to bone marrow and adipose tissue. While expanded umbilical cord mesenchymal stem cells reported auspicious disease-modifying effects in preventing OA progression in animal models, placenta/amniotic tissue also reported deleterious effects on OA joints. Lower evidence has been found for other cellular sources such as embryonic, synovial, peripheral blood, dental-pulp, cartilage, meniscus, and muscle-derived products. LEVEL OF EVIDENCE: Level II.

Fetal Vertebral Chondrostasis-Significance of Excessive Cartilage in Vertebral Bodies of Newborns.

INTRODUCTION: We describe an abnormality in fetal and neonatal vertebral bodies whose most conspicuous characteristic is an increase in cartilaginous matrix within cancellous osseous trabeculae. We have termed this finding fetal chondrostasis (FC). METHODS: We initiated a retrospective review of autopsy reports in which this condition had been prospectively diagnosed during a 36-year period. The Chalkley point counting method was applied to histologic sections of vertebral bodies to assess the relative components of cartilage, bone, and bone marrow. The results were compared to those of three control groups whose causes of death were prematurity, birth trauma, and infection. RESULTS: We found that on average, the cartilaginous content in the FC group was considerably greater in both preterm and term infants when compared to controls. FC seemed to evolve from diminished activity in the cartilaginous growth zone resulting in formation of excessively broad cartilaginous columns. These subsequently suffered from delayed resorption following their incorporation within cancellous bony trabeculae. CONCLUSION: Excess cartilage within cancellous bone of vertebral centra in newborns is merely one aspect of disturbed intrauterine osseous development but is seemingly more readily discernible than other features at this site. The most common clinical correlates for FC were multiple congenital anomalies, congenital heart disease, intrauterine growth retardation, prematurity, and certain maternal factors.