Cartilage Defects Research Articles

Effect of collagen-based scaffolds with hydroxyapatite on the repair of cartilage defects in the rabbit knee joint

BackgroundThe repair of articular cartilage defects is always a significant clinical challenge in joint treatment. Therefore, the aim of this study was to investigate that the ColII-HA-CS-HAP scaffolds with BMSCs could repair cartilage defects of knee.MethodsBone marrow mesenchymal stem cells (BMSCs) were extracted from rabbits, identified using immunofluorescence staining, and successfully induced into chondrocytes. Type II collagen (ColII) was isolated from bovine cartilage and constructed into scaffolds with hyaluronic acid, chondroitin sulfate, and hydroxyapatite. Then BMSCs were seeded on the ColII-HA-CS-HAP scaffold to detect biocompatibility.ResultsThe results of DAPI fluorescence staining showed that the number of BMSCs on the ColII-HA-CS-HAP scaffolds increased rapidly after culturing for 12 d. The rabbit knee cartilage defect model with a diameter of approximately 3 mm and a thickness of approximately 4 mm was selected to evaluate the regenerative potential of the scaffolds using histological and immunohistochemical analyses. At 6 months, the regenerated cartilage in the ColII-HA-CS-HAP scaffolds with BMSCs was more similar to that of native cartilage than the ColII-HA-CS-HAP scaffold group.ConclusionsOur study proved that the ColII-HA-CS-HAP scaffolds with differentiated BMSCs can produce an excellent healing response and repair cartilage defects successfully in a rabbit model.

Application of miR-29a-Exosome and Multifunctional Scaffold for Full-Thickness Cartilage Defects

BackgroundFull-thickness cartilage defect is a common refractory disease in orthopedics. In this study, we designed a novel composite scaffold composed of silk fibroin-chitosan for the cartilage layer and porous tantalum for the subchondral bone layer, loaded with engineered bone mesenchymal stem cell exosomes, to evaluate its efficacy in repairing full-thickness cartilage defect. MethodsPorous tantalum was 3D printed and combined with silk fibroin-chitosan to form a composite scaffold. Chondrocytes were cultured on the scaffold, and their growth was assessed using the CCK-8 method. Toluidine blue staining confirmed cell morphology, while immunofluorescence revealed collagen type Ⅱ expression. Engineered exosomes loaded with miR-29a were created and characterized using various techniques. Co-culturing with chondrocytes demonstrated their proliferation over 10 days. Immunofluorescence revealed staining for the nucleus, collagen type II, and Aggrecan. In vivo experiments were performed on rats to assess cartilage defect repair, utilizing histological staining and micro-CT scanning at 4 and 8 weeks post-operation. ResultsThe silk fibroin-chitosan scaffold demonstrated good biocompatibility, supporting chondrocyte adhesion, growth, and cartilage tissue formation. Engineered exosomes exhibited promising biological activity, conducive to bone and cartilage regeneration. The implantation of the silk fibroin-chitosan/porous tantalum composite scaffold loaded with engineered exosomes promoted integration with the surrounding bone and cartilage tissues, facilitating repair and regeneration. ConclusionsThe silk fibroin-chitosan combined with porous tantalum scaffold carrying engineered exosomes loaded with miR-29a has good potential for full-thickness cartilage defects regeneration.

Anterior to Central Cartilage Defects of Arthritic Knee Showed Better Cartilage Regeneration Than Posterior Cartilage Defects using Mesenchymal Stem Cell Implantation

PurposeTo analyze cartilage regeneration and clinical outcomes after human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) implantation based on the distribution and location of medial femoral condyle (MFC) cartilage defects. MethodsPatients who underwent hUCB-MSC implantation for MFC cartilage defects involved in isolated medial compartment osteoarthritis were included. The patients were divided into two groups: those with MFC defects located within the anterior-central portion (Group A) and those with MFC defects extending to the posterior portion (Group P). Cartilage regeneration was assessed using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 scores. MFC cartilage defects were subdivided into anterior, central, and posterior regions. The total, regional MOCART scores, and patient-reported outcomes (PROs) were evaluated. ResultsOverall, 43 patients were included in this study (Group A: 31 patients, Group P: 12 patients), with 30/43 undergoing combined high tibial osteotomy. Cartilage defect size was significantly larger in Group P than in Group A (7.8±1.9 cm2 vs. 5.7±2.4 cm2, P=0.009). Group A demonstrated a significantly higher total MOCART score compared to Group P (55.0±12.3 vs. 40.4±9.2, P=0.001). PROs at final follow-up showed significant improvement compared to preoperative values in both groups (all P<0.001), with no significant differences in PROs between groups. The mean follow-ups for each group were 29.7 and 32.5 months, respectively. Defect size were significantly associated with the total MOCART score (P=0.026) and unsatisfactory outcome (MOCART < 60) (P=0.012, odds ratio 2.674). The cut-off value for defect size was 6.3 cm2 (area under the curve, 0.905; P<0.001). In the comparison of regional MOCART scores within each patient, the anterior MOCART score was significantly higher than the central and posterior MOCART scores (P<0.001 and P=0.004, respectively). ConclusionCartilage defects with osteoarthritis, which is smaller and primarily limited to the anterior-to-central portion showed better MOCART scores after hUCB-MSC implantation.

Arthroscopic Autologous Minced Cartilage Implantation of Cartilage Defects in the Knee: A 2-Year Follow-up of 62 Patients.

Symptomatic cartilage defects of the knee joint are frequently diagnosed and can be treated with different available surgical methods. Nevertheless, there is currently no gold standard treatment for all indications. Minced cartilage implantation is increasingly coming into focus as a refined surgical technique. To investigate the 2-year clinical and radiological outcomes of arthroscopic autologous minced cartilage repair with the standardized commercial implantation system AutoCart. Case series; Level of evidence, 4. A total of 62 consecutive patients were included and prospectively evaluated preoperatively and at 3, 6, 12, and 24 months postoperatively. Outcomes were assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Single Assessment Numeric Evaluation (SANE), and Tegner activity scale at all follow-up time points. The examination of preoperative magnetic resonance imaging (MRI) was performed using the Area Measurement and Depth and Underlying Structures (AMADEUS) score, and the examination of MRI at 24 months was performed using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score. There were 34 male and 28 female patients (mean age, 38.79 ± 10.78 years) with symptomatic cartilage lesions with a mean defect size of 2.53 ± 1.24 cm2. Lesions were predominantly International Cartilage Repair Society grade 3 located in the region of the femoral condyles. Concomitant surgery was performed in 40.3% of patients. The total KOOS score significantly improved from 62.4 ± 13.1 at baseline to 74.4 ± 15.9 at 24 months (P < .001). The secondary outcome measures of the VAS, WOMAC, and SANE showed a similar pattern, with score improvements in the follow-up period compared to baseline. The mean AMADEUS score was 64.75 ± 13.87, while the mean MOCART 2.0 score was 62.88 ± 9.86, among 20 available patients. The revision surgery rate was 8.1% mainly because of hypertrophy (6.5%). Among this cohort of patients, minced cartilage implantation demonstrated satisfying 2-year outcomes with increased patient-reported outcome measure scores from 3 to 24 months postoperatively. Regenerated tissue quality on MRI was comparable to that using other cartilage repair methods and showed no associations with patient characteristics or patient-reported outcome measures. Larger cohorts, longer postoperative intervals, and comparable trials are needed to further evaluate the role of this technique in treating cartilage defects.

Magnetic Soft Catheter Robot System for Minimally Invasive Treatments of Articular Cartilage Defects.

Articular cartilage defects are among the most common orthopedic diseases, which seriously affect patients' health and daily activities, without prompt treatment. The repair biocarrier-based treatment has shown great promise. Total joint injection and open surgery are two main methods to deliver functional repair biocarriers into the knee joint. However, the exhibited drawbacks of these methods hinder their utility. The repair effect of total joint injection is unstable due to the low targeting rate of the repair biocarriers, whereas open surgery causes serious trauma to patients, thereby prolonging the postoperative healing time. In this study, we develop a magnetic soft catheter robot (MSCR) system to perform precise in situ repair of articular cartilage defects with minimal incision. The MSCR processes a size of millimeters, allowing it to enter the joint cavity through a tiny skin incision to reduce postoperative trauma. Meanwhile, a hybrid control strategy combining neural network and visual servo is applied to sequentially complete the coarse and fine positioning of the MSCR on the cartilage defect sites. After reaching the target, the photosensitive hydrogel is injected and anchored into the defect sites through the MSCR, ultimately completing the in situ cartilage repair. The in vitro and ex vivo experiments were conducted on a 3D printed human femur model and an isolated porcine femur, respectively, to demonstrate the potential of our system for the articular cartilage repair.

Osteochondral Abnormalities on Three-Dimensional Ultrashort Echo Time MRI Scans Are Associated with Knee Cartilage Degradation.

Background The calcified cartilage layer and subchondral bone plate (SBP) contribute to osteoarthritis development. Three-dimensional (3D) ultrashort echo-time (UTE) MRI can help to evaluate calcified cartilage and SBP in various stages of cartilage degradation. Purpose To compare calcified cartilage and SBP abnormalities using 3D UTE MRI with cartilage degradation and osteochondral junction (OCJ) abnormalities observed at proton-density fast spin-echo with fat suppression (PDFS) MRI. Materials and Methods Between April 2018 and March 2019, 143 participants were prospectively enrolled in this study and underwent routine knee MRI with an additional sagittal 3D UTE MRI examination for chronic knee pain. The MRI scans were retrospectively analyzed by two musculoskeletal radiologists independently and at consensus. Cartilage degradation grades and OCJ abnormalities were evaluated at PDFS MRI. Calcified cartilage and SBP abnormalities were assessed at 3D UTE MRI by considering the location of cartilage degradation. The relationship between cartilage degradation grade and abnormalities of calcified cartilage and SBP was assessed using Spearman rank correlation analysis. The association between OCJ abnormalities on PDFS MRI scans and calcified cartilage and SBP abnormalities was analyzed using logistic regression models. Results In total, 143 knees (71 right and 72 left knees) from 143 participants (mean age, 50.8 years ± 17.6 [SD]; 72 male and 71 female participants) were analyzed. On 3D UTE MRI scans, calcified cartilage defects showed a moderate positive correlation with the cartilage degradation grade (ρ = 0.49-0.52; P < .001). Calcified cartilage thinning (ρ = 0.2-0.3; P < .001), SBP irregular thickening (ρ = 0.3-0.35; P < .001), and defects (ρ = 0.34-0.42; P < .001) exhibited a weak positive correlation with the cartilage degradation grade. OCJ abnormalities depicted at PDFS MRI were associated with calcified cartilage and SBP abnormalities (P < .05). Conclusion Calcified cartilage layer and SBP abnormalities at 3D UTE MRI were associated with cartilage degradation and OCJ abnormalities depicted at PDFS MRI. © RSNA, 2024 Supplemental material is available for this article.

Novel Treatment Options for Knee Cartilage Defects in 2023: Erratum.

Novel Treatment Options for Knee Cartilage Defects in 2023: Erratum.

Biphasic cartilage repair implant versus microfracture in the treatment of focal chondral and osteochondral lesions of the knee: a prospective, multi-center, randomized clinical trial

BackgroundAutologous minced cartilage is a method for cartilage defect repair, and our study focuses on a newly developed biphasic cylindrical osteochondral construct designed for use in human knees. We aimed to compare its clinical effectiveness and safety with microfracture, the commonly utilized reparative treatment for knee chondral or osteochondral defects.Materials and methodsConducted as a prospective multicenter, randomized controlled, non-inferiority trial across nine hospitals, the study involved 92 patients with International Cartilage Repair Society (ICRS) grade 3 to 4 chondral or osteochondral lesions on femoral condyles. Patients were evenly randomized to receive either the biphasic cartilage-repair implant (BiCRI) or microfracture. Functional outcomes and safety assessments were conducted at postoperative intervals of 6 weeks and 3, 6, and 12 months. Primary and secondary endpoints included International Knee Documentation Committee (IKDC) 2000 Subjective Knee Evaluation Form score improvement, the grade distribution in the IKDC 2000 Knee Examination Form, and various assessments, such as the Knee Injury and Osteoarthritis Outcome Score (KOOS), visual analog scales (VASs) for pain, MRI findings, and arthroscopic findings at 12 months.ResultsOut of the initial participants, 47 in the BiCRI group and 45 in the microfracture group completed the follow-up. At 12 months, the mean change in IKDC total score was 25.56 ± 18.48 for BiCRI and 27.51 ± 23.65 for microfracture. The 95% confidence interval (CI) for the score difference (BiCRI minus microfracture) was − 6.95, exceeding the non-inferiority margin of − 12. Secondary endpoints indicated comparable functional outcomes, and arthroscopic findings demonstrated more fully regenerated cartilage in the BiCRI group.ConclusionBased on the IKDC 2000 Subjective Knee Evaluation Form score, BiCRI proved non-inferior to microfracture at 12 months. Short-term functional outcomes were comparable to those with microfracture, while arthroscopic findings showed more complete cartilage regeneration in the BiCRI group. Consequently, BiCRI emerges as a viable alternative for treating chondral or osteochondral defects.Level of evidenceLevel 2, multi-center, randomized clinical trial.Trial registration: Name of the registry: ClinicalTrials.gov. Trial registration number: NCT01477008. Date of registration: 11/14/2011. URL of trial registry record: clinicaltrials.gov/study/NCT01477008

Decellularization of fish tissues for tissue engineering and regenerative medicine applications.

Decellularization is the process of obtaining acellular tissues with low immunogenic cellular components from animals or plants while maximizing the retention of the native extracellular matrix structure, mechanical integrity and bioactivity. The decellularized tissue obtained through the tissue decellularization technique retains the structure and bioactive components of its native tissue; it not only exhibits comparatively strong mechanical properties, low immunogenicity and good biocompatibility but also stimulates in situ neovascularization at the implantation site and regulates the polarization process of recruited macrophages, thereby promoting the regeneration of damaged tissue. Consequently, many commercial products have been developed as promising therapeutic strategies for the treatment of different tissue defects and lesions, such as wounds, dura, bone and cartilage defects, nerve injuries, myocardial infarction, urethral strictures, corneal blindness and other orthopedic applications. Recently, there has been a growing interest in the decellularization of fish tissues because of the abundance of sources, less religious constraints and risks of zoonosis transmission between mammals. In this review, we provide a complete overview of the state-of-the-art decellularization of fish tissues, including the organs and methods used to prepare acellular tissues. We enumerated common decellularized fish tissues from various fish organs, such as skin, scale, bladder, cartilage, heart and brain, and elaborated their different processing methods and tissue engineering applications. Furthermore, we presented the perspectives of (i) the future development direction of fish tissue decellularization technology, (ii) expanding the sources of decellularized tissue and (iii) innovating decellularized tissue bio-inks for 3D bioprinting to unleash the great potential of decellularized tissue in tissue engineering and regenerative medicine applications.

Evaluation of Dexamethasone-Eluting Cell-Seeded Constructs in a Preclinical Canine Model of Cartilage Repair.

In this 12-month long, preclinical large animal study using a canine model, we report that engineered osteochondral grafts (comprised of allogeneic chondrocyte-seeded hydrogels with the capacity for sustained release of the corticosteroid dexamethasone [DEX], cultured to functional mechanical properties, and incorporated over porous titanium bases), can successfully repair damaged cartilage. DEX release from within engineered cartilage was hypothesized to improve initial cartilage repair by modulating the local inflammatory environment, which was also associated with suppressed degenerative changes exhibited by menisci and synovium. We note that not all histological and clinical outcomes at an intermediary time point of three months paralleled 12-month outcomes, which emphasizes the importance of invivo studies in valid preclinical models that incorporate clinically relevant follow-up durations. Together, our study demonstrates that engineered cartilage fabricated under the conditions reported herein can repair full-thickness cartilage defects and promote synovial joint health and function.

A minimally invasive modified revolving-door flap for surgical reconstruction of concha and antihelix defects

Skin cancers affecting the concha and antihelix are quite common, because of anterior auricular projection from the head and subsequent actinic exposure, leading to the need for effective ear reconstruction post-surgery. Various methods such as skin grafts, free tissue transplantation, and local flaps have been used. This study introduces a refined technique for concha-antihelix defect reconstruction, based on a minimally invasive modification of the revolving-door flap procedure. Here, a fasciocutaneous flap technique involving minimal posterior auricular muscle contribution is used, particularly suitable for anterior skin and cartilage defects. The study included 75 patients with nonmelanocytic skin carcinoma on the ear's anterior surface, in which we evaluated patient's and surgeon's satisfaction with a visual analogue scale and discussed the surgical technique and its advantages and indications. The technique demonstrated excellent cosmetic and functional outcomes, effectively hiding donor-site deformities and ensuring patient and surgeon contentment. This approach allows for one-stage reconstruction under local anesthesia, reducing costs, surgery time, and recovery period. The procedure provides high-quality tissue for reconstruction with low complication risks, making it an optimal choice for wide conchal and antihelix defect repairs due to its proximity to the affected area and the reliable, swift nature of the method.

Articular cartilage regeneration with a microgel as a support biomaterial. A rabbit knee model

Articular cartilage has limited regenerative capacity, so focal lesions generate mechanical stress in the joint that induces an aggravation of the damage, which ultimately leads to osteoarthritis. We recently suggested the use of microgels at the site of the cartilage defect, as a support material, to generate a biomechanical environment where pluripotent cells differentiate towards the hyaline cartilage phenotype. Here we propose a chondral regeneration strategy based on subchondral bone injury, and filling the defect site with an agglomerate of two types of microspheres, some rigid made of a biodegradable polyester (40 μm mean diameter), and others with a gel consistency made of platelet-rich plasma obtained from circulating blood (70–110 μm diameter). A 3-mm diameter defect was made in the articular cartilage of the knee joint in rabbits, exposing the subchondral bone, in which incisions were made to produce bleeding. Microgels were implanted filling the defect, which was covered with a synthetic membrane of the same polyester. Three months later, cartilage regeneration was analyzed according to the International Cartilage Repair Society (ICRS) guidelines. The newly formed tissue showed histological characteristics of hyaline cartilage, being significantly closer to native cartilage than when only the membrane was implanted, mainly in parameters such as tissue (70.0 ± 20.9) and cell morphologies (100.0 ± 0.0), and surface architecture (90.0 ± 22.4) and assessment (70.0 ± 11.2), with native tissue having a value of 100. Polyester microspheres and membrane were not bioreabsorbed during the three months, but rather moved towards the subchondral bone, leaving space for the organization of the newly formed tissue.

Macrophage tracking with USPIO imaging and T2 mapping predicts immune rejection of transplanted stem cells

To develop a clinical imaging method for monitoring macrophage migration to the defect site after implantation of various stem cells and evaluating immune responses in the context of knee arthritis, T2 mapping was correlated with CD68-positive cell densities in defects and the bone marrow. This study, which was approved by the Institutional Animal Care and Use Committee, used 32 New Zealand white rabbits preloaded with ultrasmall superparamagnetic iron oxide particles (USPIOs). They were divided into groups that received different stem cell implants after osteochondral defect induction. T2 imaging was performed using a 3.0 T MR scanner, and the data were analysed via one-way ANOVA, with CD68 expression assessed via immunohistochemistry. After implantation, the T2 signal intensity increased across groups, with subgroup D1 (implantation of rat bone marrow stem cells (BMSCs)) showing the lowest T2 value early and the steepest increase in T2 values. Notable differences in CD68-positive cell density were found between Subgroup D1 and the other groups and between Subgroups A1 and C1 post-surgery. A moderate negative correlation was observed between T2 signals and CD68-positive cell density in defects (r = -0.468, p = 0.001), whereas a weak correlation was detected in the bone marrow (r = 0.096, p = 0.313). A significant link was identified between CD68-positive cell density in the bone marrow and in defects (r = -0.255, p = 0.001). This study revealed significant differences in immune responses to stem cells from different origin tissues in the context of cartilage repair. Adipose-derived stem cells (ADSCs) were found to be more likely to provoke immune rejection than were BMSCs in the repair of femoral condyle cartilage defects. Compared with allogeneic transplants, xenogeneic mesenchymal stem cell transplants were associated with prolonged immune rejection. T2 mapping technology was effective in predicting the density of CD68-positive cells, providing a valuable tool for immune monitoring in stem cell therapy.

Deep-supercooling preservation of stem cell spheroids for chondral defect repairment

Versatile mesenchymal stem cells (MSCs) play an important role in tissue engineering and regenerative medicine. MSCs in 3D spheroid have shown higher secretion and differentiation functions than suspended counterparts, and, thus, invitro cryopreservation of MSC spheroids is an indispensable technology to bridge the spatiotemporal gaps between spheroid generation and application. Traditional cryopreservation methods are inapplicable for spheroid due to severe thermal stress, toxic cryoprotectants, and ice formation. Here, we constructed and preserved human MSC (hMSC) spheroids via deep supercooling (DSC). Spheroids were DSC preserved at -12°C without ice formation for 7days, with higher cell viability, energy level, and chondrogenic differentiation capacity than suspended hMSCs. hMSCs embedded in spheroids have close cell-cell interactions via N-cadherin to activate the AKT-cytochrome c-caspase anti-apoptotic cascade during DSC preservation. Finally, preserved hMSC spheroids were capable of chondrogenic differentiation and can be co-delivered with collagen to treat rat cartilage defects invivo.

A novel chitosan-peptide system for cartilage tissue engineering with adipose-derived stromal cells

The natural healing process of cartilage injuries often fails to fully restore the tissue’s biological and mechanical functions. Cartilage grafts are costly and require surgical intervention, often associated with complications such as intraoperative infection and rejection by the recipient due to ischemia. Novel tissue engineering technologies aim to ideally fill the cartilage defect to prevent disease progression or regenerate damaged tissue. Despite many studies on designing biocompatible composites to stimulate chondrogenesis, only few focus on peptides and carriers that promote stem cell proliferation or differentiation to promote healing. Our research aimed to design a carbohydrate chitosan-based biomaterial to stimulate stem cells into the chondrogenesis pathway. Our strategy was to combine chitosan with a novel peptide (UG28) that sequence was based on the copin protein. The construct stimulated human adipose-derived stem cells (AD-SCs) cells to undergo chondrogenic differentiation. Chitosan 75/500 allows AD-SCs to grow and has no harmful effects on the cells. The combination of UG28 peptide with the chitosan composite offers promising properties for cell differentiation, indicating its potential for clinical applications in cartilage regeneration.

Increased physiological osteochondral repair via space-specific sequestrating endogenous BMP-2 founctional hydrogel

The challenge of achieving graded regeneration of adjacent tissues remains significant in tissue repair and regeneration. For instance, the disruption of the microenvironment caused by “osteogenesis mobilization” often results in fibrosis of the regenerated cartilage, ultimately leading to osteoarthritis. Inspired by the utilization of activated carbon for adsorbing and filtering small particles in air purification and water treatment, we have designed an integrated hydrogel scaffold capable of absorbing the endogenous BMP-2 produced by “osteogenesis mobilization”, confining it to the bone defect area, and preventing its diffusion into the cartilage region, thereby facilitating physiological osteochondral gradient regeneration. The osteogenic layer of this integrated scaffold is NHAP-AHAMA-B2A, which captures the BMP-2 produced by “osteogenesis mobilization” and amplifies its osteogenic effect through the grafted peptide B2A. This upregulation enhances the expression of ALP, OCN, and OPN in MSCs within the osteogenic layer, promoting osteogenic differentiation. The chondrogenic layer, HAMA-B2A, utilizes the peptide B2A to upregulate the expression of COL II and ACAN in MSCs, fostering chondrogenic differentiation. This integrated HAMA-B2A/NHAP-AHAMA-B2A hydrogel scaffold confines the BMP-2 produced by “osteogenesis mobilization” to the bone defect area, prevents its diffusion into the cartilage defect area, and effectively utilizes it to induce stem cell osteogenic differentiation. Simultaneously, it induces stem cell chondrogenic differentiation in the cartilage defect area, achieving transparent cartilage regeneration. In summary, the osteogenic and chondrogenic layers of this integrated scaffold collaborate to achieve a physicochemical gradient regeneration of bone-cartilage.

Engineered dECM-based microsystem promotes cartilage regeneration in osteoarthritis by synergistically enhancing chondrogenesis of BMSCs and anti-inflammatory effect

The cartilage defects in osteoarthritis (OA) often result in loss of supporting and cushioning functionalities. Along this line, tissue engineering strategies for microfluidics based on high-precision control capabilities have been developed as promising long-term therapeutic solutions for cartilage regeneration in OA towards implementing anti-inflammatory effects and subsequent chondroprotective regeneration. In this study, an engineered microcarrier comprising composite porous microspheres based on decellularized extracellular matrix (dECM) and poly(lactic-co-glycolic acid) (PLGA) encapsulating icariin (ICA) was fabricated by microfluidic technology. This microcarrier, co-cultured with bone marrow mesenchymal stem cells (BMSCs), was developed as an injectable engineered microsystem for cartilage regeneration in OA. Mechanistically, dECM effectively repaired cartilage defects by inducing the differentiation of encapsulated stem cells to a cartilage phenotype through microenvironmental effects. In addition to enhanced secretion of active anti-inflammatory substances from BMSCs by dECM, the gradual release of ICA from the degraded PLGA PMs synergized anti-inflammatory effects in vivo, resulting in effective cartilage regeneration in OA. In short, the engineered microsystem indicated favorable effects in protecting and repairing cartilage, highlighting their potential as a promising therapeutic intervention for effectively ameliorating OA.

3D printed sodium alginate/gelatin/tannic acid/calcium chloride scaffolds laden bone marrow mesenchymal stem cells to repair defective thyroid cartilage plate.

Due to the absence of blood vessels, cartilage exhibits extremely limited self-repair capacity. Currently, repairing laryngeal cartilage defects, resulting from conditions such as laryngeal tumors, injury, and congenital structural abnormalities, remains a significant challenge in the Department of Otolaryngology, Head and Neck Surgery. Previous research has often focused on enhancing the mechanical properties of synthetic materials. However, their low biological activity and weak cell adhesion necessitate compensatory measures. This study aims to capitalize on the advantages of natural materials in cartilage tissue engineering. Sodium alginate, gelatin, tannic acid, and calcium chloride were utilized to prepare bioinks through cross-linking for application in 3D printing cartilage scaffolds. Bone marrow mesenchymal stem cells with multidirectional differentiation potential were chosen as seed cells, with appropriate growth factors incorporated to promote their differentiation into cartilage during in vitro culture. The scaffold laden cells was subsequently implanted into rabbit thyroid cartilage plate defects at the appropriate time. HE staining, toluidine blue staining, Masson staining, and collagen type II staining were employed to assess cartilage defect repair at 4, 8, and 12 weeks, respectively. Results demonstrated that scaffolds made from natural materials could emulate the mechanical properties of fresh cartilage with commendable biocompatibility. Stained sections further confirmed the efficacy of the composite hydrogel scaffolds identified in this study in promoting rabbit thyroid cartilage plate restoration. In summary, this study successfully fabricated a natural material scaffold for rabbit laryngeal cartilage tissue engineering, thereby furnishing a new idea and experience for the clinical application of laryngeal cartilage defect reconstruction.

Osteochondral Lesion of the Lateral Femoral Condyle Following Patellar Dislocation – Treatment of a Rare Injury in Adolescents: A Case Study

Introduction: Osteochondral injuries of the knee are increasingly common among active adolescents, often resulting from acute trauma, repetitive microtrauma, or conditions like osteochondritis dissecans. Patellar dislocation is a frequent cause of osteochondral lesions (OCL). Studies indicate that a significant percentage of patients with patellar dislocation exhibit OCLs, particularly in the anterior lateral femoral condyle and medial portion of the patella. Case presentation: A case study of a 15-year-old female athlete illustrates the clinical presentation and management of such injuries. After sustaining a knee injury during a football match, she experienced significant pain and swelling, with imaging revealing an osteochondral defect in the lateral gutter. Surgical intervention confirmed the presence of a larger deffect and involved stabilizing the osteochondral fragment and repairing the surrounding cartilage. Postoperative management included a period of non-weight-bearing followed by gradual rehabilitation. Follow-up MRIs showed complete integration of the cartilage defect, and the patient successfully returned to football practice six months post-surgery. Conclusion: This case highlights the importance of early recognition and appropriate treatment of osteochondral injuries in adolescents. Surgical techniques, including chondral fixation, can be effective, particularly in skeletally immature patients, facilitating a successful return to athletic activities. Early intervention is crucial for preserving joint function and ensuring optimal recovery outcomes.

MRI manifestations and quantitative parameters of fat pad PDW-SPAIR in patients with knee osteoarthritis and their predictive value

Background Knee osteoarthritis (KOA) is a degenerative joint disease characterized by the breakdown of cartilage and underlying bone, often leading to pain and stiffness. There is limited research on the correlation between magnetic resonance imaging (MRI) manifestations and changes in quantitative parameters of the proton density-weighted spectral attenuated inversion recovery (PDW-SPAIR) sequence in the fat pad of KOA patients. Objective To investigate the MRI manifestations and quantitative parameters of fat pad PDW-SPAIR in patients with KOA and their predictive value. Methods 82 patients with KOA admitted to the hospital from January 2023 to January 2024 were selected as the study subjects. All of them received an MRI examination before the operation. Their MRI manifestations and quantitative parameters of fat pad PDW-SPAIR were analyzed to evaluate their application value in patients with KOA. Results Among the 82 patients, there were 25 cases of bony defects, 43 cases of cartilage defects, and 14 cases of hydrops articuli. There were 63 cases of bone marrow edema, 54 cases of soft tissue swelling, 68 cases of synovitis, and 42 cases of bone erosion. Different quantitative parameters of fat pad PDW-SPAIR showed that patients with cartilage defects were 50, 53, 32, and 32. Cartilage defects were 130, 131, 53, and 49. There were statistically significant differences in signal intensity ratios of non-cartilage and cartilage defects displayed by different quantitative parameters of fat pad PDW-SPAIR (p &lt; 0.05). Spearman correlation analysis showed that PD-FSE-SAG-SPAIR, PD-FSE-COR-SPAIR, T2-FSE-SAG, and T1-FSE-COR positively correlated with KOA (p &lt; 0.05). Conclusion MRI manifestations and quantitative parameters of fat pad PDW-SPAIR may be helpful for the clinical prediction of KOA.