Cartilage Structure Research Articles

Advancing drug delivery to articular cartilage: From single to multiple strategies.

Articular cartilage (AC) injuries often lead to cartilage degeneration and may ultimately result in osteoarthritis (OA) due to the limited self-repair ability. To date, numerous intra-articular delivery systems carrying various therapeutic agents have been developed to improve therapeutic localization and retention, optimize controlled drug release profiles and target different pathological processes. Due to the complex and multifactorial characteristics of cartilage injury pathology and heterogeneity of the cartilage structure deposited within a dense matrix, delivery systems loaded with a single therapeutic agent are hindered from reaching multiple targets in a spatiotemporal matched manner and thus fail to mimic the natural processes of biosynthesis, compromising the goal of full cartilage regeneration. Emerging evidence highlights the importance of sequential delivery strategies targeting multiple pathological processes. In this review, we first summarize the current status and progress achieved in single-drug delivery strategies for the treatment of AC diseases. Subsequently, we focus mainly on advances in multiple drug delivery applications, including sequential release formulations targeting various pathological processes, synergistic targeting of the same pathological process, the spatial distribution in multiple tissues, and heterogeneous regeneration. We hope that this review will inspire the rational design of intra-articular drug delivery systems (DDSs) in the future.

High tibial osteotomy as a treatment protocol for osteoarthritis of a knee- time for a change?

Osteoarthritis is a common degenerative condition of the joints, consisting of retrogressive sequence of cell and matrix changes that result in loss of articular cartilage structure and function. It affects all ethnic groups in all geographic locations. There are several treatment options available for early OA knee including non pharmacological, pharmacological treatment and various surgical treatment. An arthroplasty is a good option for low demand and older patients there remains a significant concern regarding the longevity of implant, particularly in younger patients whereas high tibial osteotomy is joint preserving surgery . The normal anatomical tibial bone shape is maintained after the HTO, which allows for conversion to knee replacement if required in future . Early ambulation and weight bearing on operated limb is possible with use of orthofix .Orthofix does not require additional surgery for implant removal and bone graft is also not needed.

Histological characterization of the human scapholunate ligament.

The scapholunate interosseous ligament (SLIL) plays a fundamental role in stabilizing the wrist bones, and its disruption is a frequent cause of wrist arthrosis and disfunction. Traditionally, this structure is considered to be a variety of fibrocartilaginous tissue and consists of three regions: dorsal, membranous and palmar. Despite its functional relevance, the exact composition of the human SLIL is not well understood. In the present work, we have analyzed the human SLIL and control tissues from the human hand using an array of histological, histochemical and immunohistochemical methods to characterize each region of this structure. Results reveal that the SLIL is heterogeneous, and each region can be subdivided in two zones that are histologically different to the other zones. Analysis of collagen and elastic fibers, and several proteoglycans, glycoproteins and glycosaminoglycans confirmed that the different regions can be subdivided in two zones that have their own structure and composition. In general, all parts of the SLIL resemble the histological structure of the control articular cartilage, especially the first part of the membranous region (zone M1). Cells showing a chondrocyte-like phenotype as determined by S100 were more abundant in M1, whereas the zone containing more CD73-positive stem cells was D2. These results confirm the heterogeneity of the human SLIL and could contribute to explain why certain zones of this structure are more prone to structural damage and why other zones have specific regeneration potential. RESEARCH HIGHLIGHTS: Application of an array of histological analysis methods allowed us to demonstrate that the human scapholunate ligament is heterogeneous and consists of at least six different regions sharing similarities with the human cartilage, ligament and other anatomical structures.

The role of autophagy in mitigating osteoarthritis progression via regulation of chondrocyte apoptosis: A review

Osteoarthritis (OA) is the most prevalent chronic joint disease with an immense socioeconomic burden; however, no treatment has achieved complete success in effectively halting or reversing cartilage degradation, which is the central pathophysiological feature of OA. Chondrocytes loss or dysfunction is a significant contributing factor to the progressive cartilage deterioration as these sole resident cells have a crucial role to produce extracellular matrix proteins, thus maintaining cartilage structure and homeostasis. It has been previously suggested that death of chondrocytes occurring through apoptosis substantially contributes to cartilage degeneration. Although the occurrence of apoptosis in osteoarthritic cartilage and its correlation with cartilage degradation is evident, the causes of chondrocyte apoptosis leading to matrix loss are still not well-understood. Autophagy, an intracellular degradative mechanism that eliminates dysfunctional cytoplasmic components to aid cell survival in unfavourable conditions, is a potential therapeutic target to inhibit chondrocyte apoptosis and reduce OA severity. Despite accumulating evidence indicating significant cytoprotective effects of autophagy against chondrocyte apoptosis, the mechanistic link between autophagy and apoptosis in chondrocytes remains to be further explored. In this review, we summarize the relevant mechanistic events that perpetuate chondrocyte apoptosis and highlight the prominent role of autophagy in modulating these events to mitigate OA progression.

Osteochondral Repair with Autologous Cartilage Transplantation with or without Bone Grafting: A Short Pilot Study in Mini-Pigs.

Treatment strategies for osteochondral defects, for which particulated autologous cartilage transplantation (PACT) is an emerging treatment strategy, aim to restore the structure and function of the hyaline cartilage. Herein, we compared the efficacy of PACT with control or human transforming growth factor-β (rhTGF-β), and clarified the necessity of bone graft (BG) with PACT to treat shallow osteochondral defects in a porcine model. Two skeletally mature male micropigs received 4 osteochondral defects in each knee. The 16 defects were randomized to (1) empty control, (2) PACT, (3) PACT with BG, or (4) rhTGF-β. Animals were euthanized after 2 months and histomorphometry, immunofluorescence analysis, semiquantitative evaluation (O'Driscoll score), and magnetic resonance observation of cartilage repair tissue (MOCART) score were performed. Hyaline cartilages, glycosaminoglycan synthesis, and collagen type II staining were more abundant in the PACT than in the control and rhTGF-β groups. The O'Driscoll score was significantly different between groups (P < 0.001), with both PACT groups showing superiority (P = 0.002). PACT had the highest score (P = 0.002), with improved restoration of subchondral bone compared with PACT with BG. The MOCART score showed significant differences between groups (P = 0.021); MOCART and O'Driscoll scores showed high correlation (r = 0.847, P < 0.001). Treatment of osteochondral defects with PACT improved tissue quality compared with that with control or rhTGF-β in a porcine model. BG, in addition to PACT, may be unnecessary for shallow osteochondral defects. Clinical Relevance. BG may not be necessary while performing PACT.

From zero to ossified: Larval skeletal ontogeny of the Neotropical Cichlid fish Cichlasoma dimerus.

The identification of skeletal elements, the analysis of their developmental sequence, and the time of their appearance during larval development are essential to broaden the knowledge of each fish species and to recognize skeletal abnormalities that may affect further fish performance. Therefore, this study aimed to provide a general description of the development of the entire skeleton highlighting its variability in Cichlasoma dimerus. Larvae of C. dimersus were stained with alcian blue and alizarin red from hatching to 25 days posthatching. Skeletogenesis began with the endoskeletal disk and some cartilage structures from the caudal fin and the splachnocranium, while the first bony structure observed was the cleithrum. When larvae reached the free-swimming and exogenous feeding stage, mostly bones from the jaws, the branchial arches, and the opercle series evidenced some degree of ossification, suggesting that the ossification sequence of C. dimerus adjusts to physiological demands such as feeding and ventilation. The caudal region was the most variable regarding meristic counts and evidenced higher incidence of bone deformities. In conclusion, this work provides an overview of C. dimerus skeletogenesis and lays the groundwork for further studies on diverse topics, like developmental plasticity, rearing conditions, or phylogenetic relationships.

Single-cell RNA sequencing reveals distinct chondrocyte states in femoral cartilage under weight-bearing load in Rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common autoimmune joint disease, the pathogenesis of which is still unclear. Cartilage damage is one of the main manifestations of the disease. Chondrocytes are the main functional component of articular cartilage, which is relevant to disease progression. Mechanical loading affects the structure and function of articular cartilage and chondrocytes, but the effect of weight bearing on chondrocytes in rheumatoid arthritis is still unclear. In this paper, single-cell RNA sequencing (scRNA-seq) was performed on collected cartilage from the weight-bearing region (Fb group) and non-weight-bearing region (Fnb group) of the femur, and the differences between the Fb and Fnb groups were analyzed by cell type annotation, pseudotime analysis, enrichment analysis, cell interactions, single-cell regulatory network inference and clustering (SCENIC) for each cell type. A total of 87,542 cells were analyzed and divided into 9 clusters. Six chondrocyte subpopulations were finally identified by cellular annotation, and two new chondrocyte subtypes were annotated as immune-associated chondrocytes. The presence of each chondrocyte subpopulation and its distribution were verified using immunohistochemical staining (IHC). In this study, the atlas of femoral cartilage in knee rheumatoid arthritis and 2 new immune-related chondrocytes were validated using scRNA-seq and IHC, and chondrocytes in the weight-bearing and non-weight-bearing regions of the femur were compared. There might be a process of macrophage polarization transition in MCs in response to mechanical loading, as in macrophages. Two new immune-associated chondrocytes were identified. MCs have contrasting functions in different regions, which might provide insight into the role of immune and mechanical loading on chondrocytes in the development of knee rheumatoid osteoarthritis.

The Promise of Regenerative Medicine in the Reconstruction of Auricular Cartilage Deformities.

There are many physiologic and psychologic challenges associated with ear cartilage deformities which are incredibly distasteful to patients, particularly children. The development of regenerative medicine (RM) sciences has opened up a new window for the reconstruction of auricular cartilage because it allows the creation of a structure similar to the auricular in appearance and function. As part of this review, we discuss the role that each RM tool, including tissue engineering, cells, and biomolecules, plays in developing engineered auricular tissue. In previous studies, it was shown that the simultaneous use of natural and synthetic biomaterials as well as three-dimensional printing techniques could improve the biological and mechanical properties of this tissue. Another critical issue is using stem cells and differentiated cartilage cells to produce tissue-specific cellular structures and extracellular matrix. Also, the importance of choosing a suitable animal model in terms of handling and care facilities, physiologic similarities to humans, and breed uniformity in the preclinical assessments have been highlighted. Then, the clinical trials registered on the clinicaltrials.gov website, and the commercialized product, called AuriNovo, have been comprehensively explained. Overall, it is important to provide engineered auricular cartilage structures with acceptable safety and efficacy compared with standard methods, autologous cartilage transplantation, and prosthetic reconstruction in RM.

Cartilage-specific Sirt6 deficiency represses IGF-1 and enhances osteoarthritis severity in mice

ObjectivesPrior studies noted that chondrocyte SIRT6 activity is repressed in older chondrocytes rendering cells susceptible to catabolic signalling events implicated in osteoarthritis (OA). This study aimed to define the effect...

Recent progress on 3D-printed gelatin methacrylate-based biomaterials for articular cartilage repair

The structure and composition of articular cartilage is complex, and its self-healing ability is limited, and thus, it is difficult to achieve ideal healing once the articular cartilage is damaged. Recently, three-dimensional (3D) printing technology has provided a new possibility for the repair of articular cartilage. Engineered cartilage tissues can be fabricated by superimposing customized inks, considering different geometric structures and components of tissues. 3D printing can be effectively used to manufacture high-precision structures with complex geometry, solving the shortcomings of traditional scaffold fabrication techniques. Gelatin methacrylate (GelMA) is modified gelatin and is currently a widely used 3D printing ink due to its photocrosslinking properties. With good biocompatibility and tunable physical properties, it can provide a good scaffold platform for cell proliferation and growth factor release. Given that the role of 3D printing technology in cartilage repair has been widely reported, this article reviews the research progress of 3D-printed GelMA-based biomaterials in articular cartilage tissue engineering. We focus primarily on how 3D printing technology addresses the existing challenges inherent to the field of articular cartilage tissue engineering. We accentuate the modifications implemented in GelMA-based 3D printing scaffolds to optimize articular cartilage regeneration. Additionally, we provide a comprehensive summary of the utilization of GelMA-based biomaterials incorporating various cells, growth factors, or other tissue components and highlight how these adaptations, in conjunction with the benefits of 3D printing technology, facilitate improvements the articular cartilage repair.

SDMT: Spatial Dependence Multi-Task Transformer Network for 3D Knee MRI Segmentation and Landmark Localization

Knee segmentation and landmark localization from 3D MRI are two significant tasks for diagnosis and treatment of knee diseases. With the development of deep learning, Convolutional Neural Network (CNN) based methods have become the mainstream. However, the existing CNN methods are mostly single-task methods. Due to the complex structure of bone, cartilage and ligament in the knee, it is challenging to complete the segmentation or landmark localization alone. And establishing independent models for all tasks will bring difficulties for surgeon's clinical using. In this paper, a Spatial Dependence Multi-task Transformer (SDMT) network is proposed for 3D knee MRI segmentation and landmark localization. We use a shared encoder for feature extraction, then SDMT utilizes the spatial dependence of segmentation results and landmark position to mutually promote the two tasks. Specifically, SDMT adds spatial encoding to the features, and a task hybrided multi-head attention mechanism is designed, in which the attention heads are divided into the inter-task attention head and the intra-task attention head. The two attention head deal with the spatial dependence between two tasks and correlation within the single task, respectively. Finally, we design a dynamic weight multi-task loss function to balance the training process of two task. The proposed method is validated on our 3D knee MRI multi-task datasets. Dice can reach 83.91% in the segmentation task, and MRE can reach 2.12 mm in the landmark localization task, it is competitive and superior over other state-of-the-art single-task methods.

Ultrasonographic assessment of knee joint in patients with diabetes mellitus: comparison of sonographic changes in distal femoral cartilage and tendon structures with non-diabetics patients.

The aim of this study was to evaluate the adverse effects of diabetes mellitus on the knee joint by using ultrasonography. One hundred and two subjects with diabetes for 5 years and more were compared prospectively with 93 age and sex-matched healthy subjects. Individuals in both groups were aged between 40-55, had a body mass index below 30 kg/m2, and had no knee joint complaints. Femoral cartilage thickness, cartilage surface, quadriceps and patellar tendon thickness in both knees were assessed by ultrasonography using a 5-12 mHz linear transducer. According to ultrasonographic findings, thin and irregular femoral cartilage was more common in diabetic patients than in healthy controls (p<0.05). Diabetic patients had thinner quadriceps tendons compared to the control group (p<0.001). No statistically significant difference was recorded in patellar tendon thickness (right knee p=0.697, left knee p=0.639). The presence of effusion in the suprapatellar recess of the right knee was more common in diabetics than non-diabetics (p=0.006). Irregularity and thinning of the distal femoral cartilage in diabetics may indicate cartilage degeneration. In addition, the decrease in the thickness of the quadriceps tendon may lead to instability and adversely affect the knee joint. These sonographic findings may indicate early knee joint degeneration, so ultrasonography may help determine the possible risk of osteoarthritis in diabetic patients.

Vaşak (Lynx lynx)’ta Larynx Kıkırdakları, Trachea ve Akciğerler Üzerine Makroanatomik ve Histolojik Bir Çalışma

In this study the larynx, trachea, and lungs of one 1.5-year-old adult female lynx (Lynx lynx) were examined. The macro anatomical and histological structure of the larynx cartilages, trachea, and lungs were tried to be revealed by dissection and measurements. It was determined that the trachea had 48 cartilage rings (cartilago trachealis) up to the bifurcatio trachealis, the diameters of which narrow as they approach the lungs. The total tracheal length was 172.36 mm. It was seen that the cross-section of the lynx trachea resembled a circle. The hyaline cartilage structure surrounding the trachea was determined. A muscle structure called musculus transversus trachea, which closes the open ends of this cartilage and surrounds the cartilage from the outside, was detected. It was determined that the trachea consisted of tunica mucosa, submucosa, and tunica adventitia layers. The pulmo sinister in the lynx lung consisted of two main lobes, lobus cranialis, and lobus caudalis. Lobus cranialis was also divided among itself as pars cranialis and pars caudalis. Pulmo dexter was divided into four main lobes as lobus cranialis, lobus medius, lobus caudalis, and lobus accessorius. It was determined that there was connective tissue capsule surrounding the lung, respiratory bronchioles, alveoli, intraalveolar septum, and abundant blood vessels. In intraalveolar septum; capillaries, erythrocytes were determined. Type I and type II pneumocytes were seen covering the alveolar surface. In addition, it was determined that there were macrophages in the alveolar sacs.

Embryonic development of Indonesian native fish yellow rasbora (Rasbora lateristriata)

ObjectivesYellow rasbora (Rasbora lateristriata) exhibits potential as a novel animal model for research purposes. Nevertheless, the process of embryonic development of this fish species remains inadequately comprehended. This study aimed to characterize the embryonic development stages of yellow rasbora. MethodsThe embryonic development was documented using time-lapse technique to observe the following parameters: the embryonic cleavage, the blastomere, the epiboly area, and the somites. Heart development and morphological changes were also observed, including the number of heartbeats at 24, 30, 48 h post-fertilization. The cartilage structure in the cranium of larvae aged 1 to 3 days post-fertilization were observed as well. Alizarin red and Alcian blue staining were used to stain bone and cartilage structures. ResultsThe results of this study describe the important stages of embryogenesis in yellow rasbora, including the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching stages. The first contraction of the heart muscle was observed at 20 h post-fertilization, with cardiac tube looping occurred at 24–30 h post-fertilization. The cranium cartilage was formed 2 days post-fertilization and completed at 3 days post-fertilization. ConclusionIn conclusion, this study provided a comprehensive overview of the developmental stages of yellow rasbora embryos.

3D-bioprinted cell-laden hydrogel with anti-inflammatory and anti-bacterial activities for tracheal cartilage regeneration and restoration

Despite the notable advances in tissue-engineered tracheal cartilage (TETC), there remain several challenges that need to be addressed, such as uneven cell distribution for cartilage formation, customized C-shaped tracheal morphology, local inflammatory reactions, and infections. To overcome these challenges, this study proposed the addition of icariin (ICA) and chitosan (CS) into a gelatin methacryloyl (GelMA) hydrogel to develop a new ICA/CS/GelMA hydrogel with anti-inflammatory and anti-bacterial properties, and three-dimensional (3D)-bioprinting feasibility. The aim of this study was to construct a TETC, a customized C-shaped cartilage structure, with uniform chondrocyte distribution as well as anti-inflammatory and anti-bacterial functions. Our results confirmed that ICA/CS/GelMA hydrogel provides desirable rheological properties, suitable printability, favorable biocompatibility, and simulated microenvironments for chondrogenesis. Moreover, the addition of ICA stimulated chondrocyte proliferation, extracellular matrix synthesis, and anti-inflammatory ability, while the encapsulation of CS enhanced the hydrogels&amp;rsquo; anti-bacterial ability. All these led to the formation of an enhanced TETC after submuscular implantation and an elevated survival rate of experimental rabbits after orthotopic tracheal transplantation. This study provides a reliable cell-laden hydrogel with anti-inflammatory and anti-bacterial activities, suitable printability, and significant advancements in in vivo cartilage regeneration and in situ tracheal cartilage restoration.

Shear wave elastography and T2* mapping in the detection of early-stage trochlear cartilage damage.

The presence of degenerative changes in joint cartilage is one of the major features in osteoarthritis. To investigate the contribution of shear wave elastography and T2* mapping to the early diagnosis of femoral trochlear cartilage damage. A total of 30 individuals whose trochlear cartilage structure was evaluated as normal in conventional magnetic resonance imaging (MRI) sequences (control group) were prospectively compared with 30 patients who had early-stage cartilage damage findings on conventional MRI (study group), by performing B-mode ultrasonography, shear wave elastography, and T2* mapping. Cartilage thickness, shear wave, and T2* mapping measurements were recorded. After evaluating B-mode ultrasound and conventional MRI sequences, cartilage thickness was found to be significantly higher in the study group on both B-mode ultrasound and MRI. Shear wave velocity values of the study group (medial condyle [MC] 4.65 ± 1.11 m/sn, intercondylar [IC] 4.74 ± 1.20 m/sn, and lateral condyle [LC] 5.42 ± 1.48 m/sn) were observed to be significantly lower than the control group (MC 5.60 ± 0.77 m/sn, IC 5.85 ± 0.96 m/sn, and LC 5.63 ± 1.05 m/sn) (P < 0.05). T2* mapping values were significantly higher in the study group (MC 32.38 ± 4.04 ms, IC 35.78 ± 4.85 ms, and LC 34.04 ± 3.40 ms) than that of the control group (MC 28.07 ± 3.29 ms, IC 30.63 ± 3.45 ms, and LC 29.02 ± 3.24 ms). Shear wave elastography and T2* mapping are reliable methods for evaluating early-stage trochlear cartilage damage.

Effect of glycosaminoglycans on the structure and composition of articular cartilage and bone of broilers

This study aimed to assess the influence of glycosaminoglycan (chondroitin and glucosamine sulfates) supplementation in the diet of broilers on the expression of matrix metallopeptidase 9 (MMP-9) and metallopeptidase inhibitor 2 (TIMP-2) genes, the synthesis of proteoglycans, collagen type II and chondrocytes, bone and cartilage macroscopy, bone mineral densitometry, bone breaking strength and mineral profile. A completely randomized design was carried out in a 3×3 factorial scheme (3 levels of chondroitin sulfate: 0.00, 0.05, and 0.10%; and 3 levels of glucosamine sulfate: 0.00, 0.15, and 0.30%), totaling 9 treatments. At 21 and 42 d of age, broilers were slaughtered, and tibias and femurs were collected for evaluation. There was an interaction (P < 0.05) of sulfates for the expression of MMP-9 and its inhibitor TIMP-2 in femur articular cartilage, as well as for the number of chondrocytes, collagen type II and proteoglycans in tibia articular cartilage, bone and cartilage macroscopy and mineral profile (P < 0.05), with better results obtained with the inclusion of chondroitin and/or glucosamine sulfates in the feed. In conclusion, chondroitin and glucosamine sulfates can be used in broiler diets in order to favor the development of the structure of the locomotor system (bones and joints), thus preventing locomotion problems.

Combining biomechanical stimulation and chronobiology: a novel approach for augmented chondrogenesis?

The unique structure and composition of articular cartilage is critical for its physiological function. However, this architecture may get disrupted by degeneration or trauma. Due to the low intrinsic regeneration properties of the tissue, the healing response is generally poor. Low-grade inflammation in patients with osteoarthritis advances cartilage degradation, resulting in pain, immobility, and reduced quality of life. Generating neocartilage using advanced tissue engineering approaches may address these limitations. The biocompatible microenvironment that is suitable for cartilage regeneration may not only rely on cells and scaffolds, but also on the spatial and temporal features of biomechanics. Cell-autonomous biological clocks that generate circadian rhythms in chondrocytes are generally accepted to be indispensable for normal cartilage homeostasis. While the molecular details of the circadian clockwork are increasingly well understood at the cellular level, the mechanisms that enable clock entrainment by biomechanical signals, which are highly relevant in cartilage, are still largely unknown. This narrative review outlines the role of the biomechanical microenvironment to advance cartilage tissue engineering via entraining the molecular circadian clockwork, and highlights how application of this concept may enhance the development and successful translation of biomechanically relevant tissue engineering interventions.

Multi-organ metastases of primary chondrosarcoma of the mammary gland of a spayed Toy Poodle

We report the clinical and histopathological findings associated with multi-organ metastases of primary mammary chondrosarcoma in a 12-year-old spayed female Toy Poodle. At post-mortem examination, multifocal, sharply demarcated, grey–white to bright brown, round nodules of variable size were randomly distributed in the lungs, myocardium, liver, pancreas, spleen, intestinal tract and kidneys. Histologically, immature cartilage structures and primitive mesenchymal cells were seen in these organs. Neoplastic cells located in the cartilaginous basophilic extracellular matrix had cytoplasmic vacuolation and round vesicular nuclei and were stained with Safranin O and Alcian blue. To the best of our knowledge, this is the first report of a multi-organ metastatic chondrosarcoma that originated in the mammary gland of a dog.

A Biphasic Hydrogel with Self-Healing Properties and a Continuous Layer Structure for Potential Application in Osteochondral Defect Repair.

The treatment of osteochondral defects remains challenging due to the limited healing capacity of cartilage and the poor results of traditional methods. Inspired by the structure of natural articular cartilage, we have fabricated a biphasic osteochondral hydrogel scaffold using a Schiff base reaction and a free radical polymerization reaction. Carboxymethyl chitosan (CMCS), oxidized sodium alginate (OSA), and polyacrylamide (PAM) formed a hydrogel (COP) as the cartilage layer, while hydroxyapatite (HAp) was incorporated into the COP hydrogel to obtain a hydrogel (COPH) as an subchondral bone layer. At the same time, hydroxyapatite (HAp) was incorporated into the COP hydrogel to obtain a hydrogel (COPH) as an osteochondral sublayer, combining the two to obtain an integrated scaffold for osteochondral tissue engineering. Interlayer interpenetration through the continuity of the hydrogel substrate and good self-healing properties due to the dynamic imine bonding of the hydrogel resulted in enhanced interlayer bond strength. In addition, in vitro experiments have shown that the hydrogel exhibits good biocompatibility. It shows great potential for osteochondral tissue engineering applications.