Search Results (1,462)

Staphylococcus aureus biofilms formed on titanium surfaces are highly relevant to orthopedic implant-associated infection and remain difficult to control after maturation. This study aimed to evaluate whether ultraviolet A (UVA, 365 nm) combined with cinnamaldehyde (CA) could improve antibiofilm activity against titanium-associated S. aureus biofilms in a stage-resolved in vitro model and to examine whether the observed responses were associated with reactive oxygen species (ROS). Early stage (8 h) and 24 h biofilm models were established on total hip arthroplasty (THA)-derived titanium discs. After condition screening, 0.5 mM CA combined with 5 min UVA exposure was selected for subsequent experiments. Biofilm biomass was assessed by crystal violet staining, bacterial viability by live/dead staining and colony-forming unit (CFU) enumeration, ROS-associated fluorescence by dihydroethidium (DHE) imaging, and biofilm-associated gene expression by quantitative real-time PCR (qRT-PCR). Chondrocyte viability was also evaluated under the selected antibiofilm-effective conditions. The combined treatment showed stage-dependent antibiofilm effects, with greater biomass reduction in the 8 h biofilm model and marked impairment of bacterial viability and culturability in both models. ROS-associated fluorescence increased under combined exposure and was partially attenuated by N-acetyl-L-cysteine (NAC) in the 24 h biofilm model. In parallel, CA + UVA was associated with lower expression levels of clfA, icaA, and icaD in the 8 h biofilm model and of icaA, icaB, and icaD in the 24 h biofilm model, with partial NAC attenuation in the latter. Chondrocyte viability was lower in all treatment groups than in the untreated control, although the combined treatment did not show an obvious additional decrease compared with the single-treatment groups. These findings indicate that UVA combined with CA exerts stage-dependent antibiofilm effects in an in vitro titanium-associated S. aureus biofilm model. The observed ROS-associated responses were consistent with, but do not establish, mechanistic involvement. The current treatment setting also requires further optimization before translational applicability can be more confidently considered. Full article

Objectives: To evaluate the effectiveness and durability of matrix-associated autologous chondrocyte implantation with periosteal flap (pMACI) in treating knee cartilage defects using clinical scores and MRI evaluations. Methods: Data were collected from 37 knees of 17 patients, with a mean follow-up of 5 years (range: 0.1–20 years). Clinical outcomes were assessed using the Lysholm Knee Scoring Scale (LKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS). Tissue quality was quantitatively evaluated using MRI T1ρ and T2 mapping (biochemical) and MR observation of cartilage repair tissue: MOCART 2.0 (morphological). A linear mixed model was used to identify factors affecting outcomes, including etiology (trauma, OCD, OA), graft site, and defect size. Results: At the 20-year follow-up, clinical scores remained significantly improved from baseline (mean LKS: 55.6 to 86.5; KOOS: 37.8 to 70.8). The biochemical MRI parameters (T1ρ and T2 values) stabilized at levels comparable to native cartilage across all etiologies and sites (p = 0.326 and 0.412, respectively), indicating stable long-term tissue quality. In contrast, the MOCART 2.0 scores significantly declined over time (annual rate: −1.14 points; p < 0.001). Etiology was a significant factor; the OA group showed significantly lower clinical and MOCART scores compared to the trauma/OCD groups (p < 0.05). However, no significant differences were found in LKS and KOOS based on graft site (p = 0.489) or defect size (p > 0.05). Conclusions: pMACI may be a highly durable treatment capable of maintaining biological tissue quality and providing clinical benefits for two decades. The observed morphological deterioration after 20 years likely reflects joint-wide aging—especially in OA cases—rather than graft failure, highlighting the importance of long-term MRI monitoring. Full article

This study focuses on the development and comprehensive evaluation of the physicochemical, mechanical, and biological properties of composites based on polyhydroxybutyrate (PHB), chitosan (Ch), and hydroxyapatite (HA) for biomedical applications. DSC and FTIR spectroscopy showed that the addition of hydroxyapatite did not significantly affect the structure of the materials, but AFM data revealed a change in the surface morphology. Variations in RMS roughness ranging from 13 to 150 nm were observed for chitosan and the composites. The density of the HA-containing samples was 0.06–0.067 g/cm³, which is higher than that of the unfilled composite (0.056 g/cm³). Optimal hydrophilic properties (contact angle 38.9°) and elasticity (damping factor 0.064) were recorded for the sample with 10% HA (PChHA10). The water absorption varied: the addition of chitosan increased the value to 7.5 g/g, compared to 2.7 g/g for pure PHB, while HA slowed the swelling kinetics (more than 180 min). A biodegradation study revealed that samples containing 10–20% HA exhibited the highest stability in an enzymatic environment, while further increases in HA content resulted in increased degradation rates. The PChHA10 is considered to offer the balanced combination of properties. The potential applications of this material in medicine include its use as a scaffold for the in vitro cultivation of osteoblasts and chondrocytes, as well as for implantation in models of bone and cartilage defects in vivo. Full article

Chondrosarcoma (CHS), the second most common primary malignant cartilage tumor, is largely resistant to conventional therapies, making surgical resection the standard treatment. Proton therapy offers a physical advantage through the Bragg peak, enabling targeted irradiation while sparing surrounding tissues. However, differential biological responses between malignant and normal cartilage cells remain poorly understood. In this study, CHS SW1353 cells and normal chondrocytes (MC615) were exposed to proton irradiation. Biological responses were assessed via clonogenic survival, cell viability, apoptosis (caspase 3/7), micronucleus formation, cell cycle profiling, and oxidative stress markers. Proteomic changes were analyzed using mass spectrometry and bioinformatics. CHS cells exhibited higher radioresistance (D₁₀ = 6.45 Gy) than normal chondrocytes (D₁₀ = 5.08 Gy), oxidative stress adaptation, G1 arrest and proteomic plasticity, whereas normal chondrocytes displayed increased oxidative stress, extracellular matrix fragility and impaired integrin signaling. Notably, the tumor-specific increased levels of Tyrosine-protein kinase Fyn and Yes1-associated transcriptional regulator (YAP1) signaling suggest molecular drivers of radioresistance. Overall, proton irradiation elicits distinct biological and proteomic responses in malignant versus normal cartilage cells. These findings highlight potential radiosensitization targets, including Fyn/Src and YAP1/Hippo pathways, while underscoring the need to optimize proton therapy to enhance tumor control while minimizing damage to healthy cartilage. Full article

Articular cartilage has a limited capacity for self-repair, and effective strategies for its regeneration remain a major clinical challenge. Full-thickness cartilage defects extending to the subchondral bone induce an enhanced inflammatory response and impair spontaneous healing. This study aimed to evaluate the regenerative potential of autologous chondrocyte transplantation using an insoluble polyethersulfone (PES) scaffold in a rabbit model of grade III articular cartilage lesions. Chondrocytes were isolated and expanded in vitro and subsequently seeded onto PES membranes. Sixty-two rabbit knees with defects extending to the subchondral bone were divided into three groups: group I received chondrocyte-seeded PES scaffolds (n = 25), group II received cell-free PES scaffolds (n = 25), and group III served as an untreated control (n = 12). Cartilage regeneration was evaluated macroscopically and histologically over 52 weeks. In addition, the chondrogenic differentiation potential of cells cultured on PES scaffolds was assessed. This study extends our previous investigations of PES scaffolds in grade IV cartilage defects to a clinically relevant grade III lesion model, enabling evaluation of regenerative outcomes at an earlier stage of cartilage degeneration. The results demonstrated superior tissue regeneration in defects treated with chondrocyte-seeded PES scaffolds compared to both control groups. These findings indicate that synthetic PES scaffolds support cartilage repair and represent a promising biomaterial for the development of cell-based therapies in articular cartilage regeneration. Full article

Background: Osteoarthritis (OA) is a multifactorial disease, including inflammation, autophagy and senescence. Published work has indicated that empagliflozin (EMP) exhibits robust anti-inflammatory and anti-senescence effects, while its role in autophagy appears paradoxical. Here, we aim to identify the chondroprotective effect of EMP on OA. Methods: An OA model was established both in vitro, by stimulating primary chondrocytes (isolated from C57BL/6J mice) with IL-1β, and in vivo, by performing (Destabilized medial meniscus) DMM surgery on C57BL/6J mice. (Western blot) WB and (quantitative real-time polymerase chain reaction) qRT-PCR analysis were employed to detect the gene expression. (Immunofluorescence) IF staining was employed to detect the expression and location of target protein. SA-β-gal staining was employed to evaluate cellular senescence. Autophagic flux was assessed using a GFP-RFP-LC3 adenoviral vector. Network pharmacology was applied to identify potential pathways for experimental validation. The effects of EMP in vivo were evaluated by μ-CT, histological and (Immunohistochemistry) IHC staining. Results: EMP promoted anabolism, inhibited the inflammatory response and catabolism in IL-1β stimulated chondrocytes. EMP enhanced autophagic activity and attenuated senescent phenotype in vitro. Mechanistically, EMP regulated the PI3K/Akt/mTOR and AMPK pathways. The chondroprotective effects of EMP were reversed by (3-methyladenine) 3-MA. EMP also ameliorated OA-related phenotype in DMM models. Compared with (Kartogenin) KGN, EMP showed more pronounced suppression of inflammatory and catabolic markers, while both compounds similarly promoted anabolic marker expression. Conclusions: These in vitro and in vivo data collectively indicates that EMP can alleviate OA both in IL-1β stimulated chondrocytes and DMM induced models. Beyond its established role in diabetes management, EMP is evaluated in the context of OA, emerging as a novel and promising therapeutic agent for OA. Full article

Shear stress is a significant consideration in 3D bioprinting systems, with implications for cell viability and behaviour. This study hypothesised that relevant levels of shear stress would be generated during the process of 3D bioprinting human nasoseptal chondrocytes in a nanocellulose alginate bioink, with implications for cell viability and chondrogenic gene expression. Through a combined approach of in silico modelling and in vitro testing, we assessed chondrocyte viability and gene expression immediately within the first 72 h post-printing. Cell viability was determined using live–dead, alamarBlue and lactate dehydrogenase assays immediately and 24 h post-printing compared to cell-only and unprinted cell–biomaterial controls. Gene expression analysis of Type 2 collagen, SOX9, aggrecan and alkaline phosphatase gene expression was performed 4 h and 72 h post-printing. Computational fluid dynamics predicted a shear stress of 292 Pa and maximum fluid velocity of 19 mm/s during the bioprinting process. No statistically significant cell death or cell lysis was detected between groups immediately post-printing; however, statistically significant chondrocyte cell death was observed at 24 h in the printed group (p = 0.047). Moreover, the bioprinting process evoked a transient initial rise in both chondrogenic (SOX9, aggrecan) and osteogenic gene expression (ALP) with a marked suppression in type 2 collagen expression at 72 h (0.05, p = 0.0005), indicating biological effects evoked by shear stress during printing. This study highlights the importance of optimising the bioprinting process to facilitate low shear stress conditions for durable cartilage tissue engineering. Full article

Hyaluronic acid (HA) is widely used in medical, cosmetic, and nutraceutical applications, yet the systemic fate of orally administered HA, particularly non-animal forms, remains poorly characterised. This study investigates the stability, absorption, metabolism, and biological effects of a novel fungal-derived HA extracted from Tremella fuciformis using a sequential in vitro multi-barrier model simulating human physiological compartments, including gastric, intestinal, hepatic, renal, chondrocyte, and keratinocyte environments. Across the gastrointestinal stages, fungal-derived HA demonstrated high structural stability, maintained molecular weight, and exerted superior antioxidant and anti-inflammatory activity compared with sodium hyaluronate. It efficiently crossed the intestinal barrier without increasing hyaluronidase activity, indicating protection from premature enzymatic degradation. In hepatic cells, fungal-derived HA exhibited reduced intracellular uptake and greater extracellular persistence, suggesting lower first-pass metabolism and suggesting improved persistence under in vitro conditions. At peripheral targets, it increased the cluster of differentiation 44 (CD44) expression and HA internalisation in chondrocytes and keratinocytes, supporting anti-inflammatory and pro-regenerative effects. Renal assessments revealed minimal excretion and no cytotoxicity, supporting potential systemic availability. Overall, these results provide the first integrated in vitro evidence describing the absorption, distribution, metabolism, and excretion process of fungal-derived HA. This supports the conclusion that this form of HA is stable, biocompatible, and bioactive with therapeutic potential for joint and skin health, as suggested by the in vitro models. Full article

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease characterized by progressive cartilage destruction, and chondrocyte apoptosis plays a critical role in TMJOA progression. As chondrocytes reside in an avascular microenvironment inside the cartilage matrix, energy production via glycolysis is crucial for their survival. This study investigated the role of the key glycolytic enzyme Hexokinase 2 (HK2) in TMJOA pathogenesis and the therapeutic potential of dental pulp stem cell-derived extracellular vesicles (DPSC-EVs). In a rat experimental TMJOA model induced by monosodium iodoacetate (MIA) intra-articular injection, we observed a significantly decreased expression of HK2 along with cartilage matrix degradation. In the in vitro study, MIA induced chondrocyte apoptosis with caspase-3 activation, accompanied by impaired glycolytic function. Intervention with DPSC-EVs effectively rescued the expression of HK2 within chondrocytes, leading to a notable restoration of cellular glycolysis. Consequently, DPSC-EV treatment markedly attenuated the progression of TMJOA by reducing chondrocyte apoptosis and improved cartilage integrity. Our findings demonstrated that DPSC-EVs represent a promising cell-free therapeutic strategy for TMJOA, exerting their protective effects by targeting HK2, thereby preserving chondrocyte viability and attenuating osteoarthritis development. Full article

Background/Objectives: The aim of this study is to evaluate whether preoperative intra-articular corticosteroid injections (CSIs) are associated with an increased risk of reoperation following matrix-associated or autologous chondrocyte implantation (MACI/ACI). Secondary aims included comparing reoperation-free survival, patient-reported outcomes (PROMs), and patient acceptable symptom state (PASS) achievement. Methods: A retrospective cohort study was conducted on adults undergoing primary MACI/ACI between 2011 and 2023 at a single academic institution. Patients with documented CSI status and ≥2 years of follow-up were included. Exclusion criteria were prior MACI/ACI, osteochondral allograft transplantation, multi-ligament reconstruction, or inadequate follow-up. Propensity score matching (2:1, no steroid/steroid) based on age, sex, BMI, laterality, procedure type, and prior surgery yielded 138 matched patients (92 no steroid, 48 steroid). The primary outcome was ipsilateral reoperation, analyzed as a binary outcome, with Kaplan–Meier reoperation-free survival and restricted mean survival time (RMST). PROMs and PASS achievement were also assessed. Statistical significance was set at p < 0.05. Results: Baseline characteristics and follow-up (6.55 ± 3.74 vs. 6.73 ± 3.99 years; p = 0.80) were similar. Graft failure rates were identical (4.3% each; p = 1.00). Reoperation occurred in 21.7% of patients without CSI and 23.9% with CSI (p = 0.83). CSI was not associated with reoperation (adjusted OR 2.28; 95% CI 0.54–9.95; p = 0.26). No significant difference in reoperation-free survival or PROMs was observed. Conclusions: Preoperative intra-articular corticosteroid injections were not associated with increased reoperation risk, inferior reoperation-free survival, or worse functional outcomes following MACI/ACI. Full article

The development of inks with suitable rheological, physicochemical, mechanical, and biological properties is crucial for the successful fabrication of functional scaffolds via extrusion-based 3D printing. In this study, collagen/chitosan hydrogels with varying polymer ratios were developed and characterized to evaluate their printability and suitability for cartilage tissue engineering. Rheological analyses revealed that all samples exhibited shear-thinning behavior and solid-like viscoelasticity, with the formulation of an 80:20 COL/CHI ratio (20CHI) demonstrating optimal filament formation and dimensional stability. Physicochemical analyses confirmed the preservation of the collagen triple helix and the formation of hydrogen bonding between chitosan and collagen. 20CHI scaffolds showed swelling capacity and high cohesiveness. In vitro studies confirmed the cytocompatibility of the scaffolds with murine fibroblasts and the ability of the scaffolds to promote adhesion, proliferation, and extracellular matrix production of both chondrocytes and adipogenic mesenchymal stem cells (aMSCs). Quantification of sulfated glycosaminoglycan (sGAG) indicated sustained matrix deposition over 28 days, particularly by chondrocytes. These findings demonstrate that 20CHI hydrogel is a promising candidate for 3D printing of biomimetic scaffolds for cartilage regeneration. Full article

Cartilage is an important yet vulnerable tissue with limited self-healing capacity, where damage often progresses to joint degeneration, which eventually leads to severe osteoarthritis (OA). Current tissue engineering strategies focus on biocompatible scaffolds for cartilage regeneration, particularly amnion (or amniotic membrane), emerging as a promising biomaterial due to its wide availability, low immunogenicity, and naturally derived microenvironment that is advantageous for cartilage regeneration. This systematic review aims to evaluate the existing evidence on the efficacy of amnion as a tissue scaffolding material for cartilage regeneration in both preclinical and clinical studies. Using terms such as “cartilage damage”, “cartilage injuries”, “amnion” and “amniotic membrane”, 19 relevant studies were identified across three major databases (PubMed, Scopus and Web of Science) until 25 December 2025. All preclinical and clinical studies that utilized amnion for cartilage repair or as cartilage tissue engineering scaffolding materials were included. Evidence quality was assessed using the OHAT and MINORS risk of bias tool. This study is prospectively registered in the PROSPERO database under the ID 1178444. The findings consistently indicate that amniotic scaffolds, regardless of processing methods or cell seeding, yield favorable outcomes without adverse effects across different species. In vitro analysis revealed that treatment groups with amnion show better cell attachment, viability, and proliferation, and higher content of cartilage-related markers expressed by the seeded cells, either chondrocyte, bone marrow-derived mesenchymal stem cells (MSCs), adipose tissue-derived MSCs, placenta-derived MSCs, umbilical cord-derived MSCs, amniotic MSCs or amniotic epithelial cells. In in vivo and ex vivo studies, amnion-treated groups demonstrated improved quality of the treated cartilage, with better integration, as indicated by higher histological scores and the presence of type II collagen (COL-II). There was an inconsistency in the reporting of cartilage defect dimensions in the in vivo models across the different studies. Nevertheless, the outcome measurements were consistently reported with histological analysis, with or without International Cartilage Repair Society (ICRS) scoring and immunohistochemistry (IHC) analysis, across the studies. Clinically, most subjects show improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) Sports and Recreation score and KOOS Quality of Life score, as well as reduced Visual Analogue Scale (VAS) average and maximum pain scores. In conclusion, preclinical and clinical studies support amnion as an ideal scaffold material for cartilage tissue engineering and regeneration. Future research should focus on optimizing and standardizing amnion scaffold preparation at a production scale to facilitate the translation of these positive outcomes into clinical applications. This study is funded by the Ministry of Higher Education Malaysia via Prototype Research Grant Scheme (PRGS/1/2021/SKK01/UM/02/1) and UM International Collaboration Grant—2023 SATU Joint Research Scheme Program: ST007-2024. Full article

Articular cartilage, a highly specialised and avascular tissue, exhibits limited regenerative potential following trauma or degenerative conditions such as osteoarthritis (OA). Conventional surgical interventions, including microfracture and autologous chondrocyte implantation (ACI), have shown limited long-term efficacy due to donor site morbidity and restricted cell proliferation. In this context, mesenchymal stromal cells (MSCs) have emerged as a promising alternative owing to their multipotency, self-renewal capacity, and low immunogenicity. While bone marrow (BM) remains the traditional source of MSCs, recent studies have reported that peripheral blood-derived mesenchymal stromal cells (PB-MSCs) may possess chondrogenic, osteogenic, and adipogenic potential comparable to that of BM-derived MSCs. PB-MSCs can be harvested through minimally invasive methods, thereby avoiding the complications associated with BM aspiration. Experimental evidence indicates that PB-MSCs exhibit strong cell viability, proliferative potential, and the ability to synthesise cartilage-specific extracellular matrix proteins, such as type II collagen and sulphated glycosaminoglycans, within three-dimensional scaffolds. Immunophenotypically, PB-MSCs express mesenchymal markers including CD29, CD44, CD90, and CD105 while lacking hematopoietic markers CD34 and CD45. Flow cytometry analyses reveal that CD105⁺ populations increase following cryopreservation, highlighting their clinical utility. In contrast to these experimentally defined PB-MSCs, the term peripheral blood stem cells (PBSCs) is used in clinical studies to describe heterogeneous, non-cultured peripheral blood-derived cell preparations, typically enriched in hematopoietic stem and progenitor cells following granulocyte colony-stimulating factor (G-CSF) mobilisation, without full mesenchymal characterisation. In vitro studies confirm successful tri-lineage differentiation, whereas in vivo investigations have demonstrated effective cartilage regeneration using PB-based clinical approaches, including postoperative intra-articular administration of hyaluronic acid (HA) combined with PBSCs, as well as implantation of PBSCs covered with a collagen membrane. Furthermore, advancements in biomaterial engineering, such as poly(ethylene glycol)–cysteine–arginine–glycine–aspartic acid (PEG-CRGD) hydrogels, have enhanced PB-MSC adhesion, proliferation, and chondrogenic differentiation while promoting immunomodulation through M2 macrophage polarisation. Despite these promising outcomes, the available evidence remains limited and heterogeneous, with substantial variability in cell definitions, experimental models, and clinical study designs, which currently constrains definitive conclusions regarding clinical efficacy. Future research should focus on optimising isolation protocols, understanding molecular pathways governing PB-MSC chondrogenesis, and standardising clinical applications. Overall, PB-MSCs represent a viable, less invasive, and translationally relevant cell source for cartilage regeneration and regenerative orthopaedic therapies Full article

Background/Objectives: SETD2 is a dual-function methyltransferase important for methylation of histone H3 at lysine 36 and α-tubulin in spindle microtubules. Genetic inactivation of SETD2 during oncogenesis drives loss of H3K36me3, genomic instability, and cancer progression. This study asked if disruption of genomic stability was a canonical feature of SETD2 inactivation via different pathways. Methods: We evaluated the impact of EPZ-719, a pharmacologic SETD2 inhibitor, and an H3.3K36M mutant histone (“oncohistone”) that binds and sequesters SETD2, on methylation activity and genomic stability in human cell lines. SETD2 activity was measured using in vitro methylation assays, H3K36me3 loss confirmed by Western analysis, and mitotic defects, specifically micronuclei and chromatin bridges, quantified with cytogenetic analysis. Results: EPZ-719 caused a dose- and time-dependent reduction in SETD2 activity on both histone and tubulin substrates, accompanied by significant increases in chromatin bridges and micronuclei in retinal pigmented epithelial (RPE-1) and 786-O ccRCC cells. Similarly, oncohistone expression markedly decreased SETD2 function, as determined by H3K36me3 levels, and induced comparable mitotic defects in 786-O cells, and aneuploidy in two chondrocyte cell lines expressing the H3.3K36M oncohistone. Combining EPZ-719 with H3.3K36M expression did not exacerbate mitotic defects beyond either oncohistone or pharmacologic inhibition alone, consistent with inhibition of SETD2 as their shared underlying mechanism of action. Conclusions: Pharmacologic inhibition and oncohistone-mediated sequestration of SETD2 converge on the induction of mitotic defects, underscoring SETD2’s essential role in maintaining genomic stability. Identification of loss of genomic stability as a canonical feature of SETD2 inactivation points to a potential therapeutic liability associated with targeting SETD2 in cancers where it is overexpressed and reveals a mechanism that could contribute to the progression of cancers expressing oncohistone mutations. Full article