Development Of Cartilage Tissue Engineering Research Articles

Chitosan-Chitosan derivative for cartilage associated disorders: Protein interaction and biodegradability

Chitosan is a well-known biomaterial in the field of cartilage tissue engineering because of its flexibility. The construction of chitosan-based scaffolds is reviewed in several production methods, including freeze-drying, gelation, salt leaching, and electrospinning. In this review, many benefits of chitosan are discussed, including the interaction of chitosan with other materials and their effects, its adaptability, high reproducibility, biocompatibility, role in cellular differentiation, interactions with TGF-β (transforming growth factor-β), protein interactions, biodegradability, influencing osteoblast expression, and potential for treating bone diseases. The study also provides information on how mathematical models are used to analyze how MSC (mesenchymal stem cells) and chondrocyte distribution in multilayer hydrogels change in response to TGF-β diffusion. Results showed that collagen has weak mechanical properties and easily disintegrates during bone tissue formation, it is difficult to use alone as a biomaterial, and new scaffolds made of whey protein isolate (WPI) and chitosan may help repair osteochondral tissue. However, the thorough analysis reveals chitosan's crucial contribution to the development of cartilage tissue engineering as well as its potential to address issues in the field.

Silk fibroin/polyacrylamide-based tough 3D printing scaffold with strain sensing ability and chondrogenic activity

Cartilage tissue plays an important role in our life activities. The poor self-repair capacity makes cartilage tissue engineering an urgent clinical demand. Among them, the development of tissue engineering scaffolds with both biomimetic features and microenvironment signal sensing abilities could significantly promote the development of cartilage tissue engineering. While most of the reported cartilage scaffolds have no intelligent sensing features. Herein, a ternary composite 3D printing scaffold with both strain sensing ability and desired mechanical property was developed, by using regenerated silk fibroin (RSF) and polyacrylamide (PAM) as main matrixes, and oxidized bacterial cellulose nanofibers (OBC) as filler. Then, the mechanical property, strain sensing ability and corresponding ectopic chondrogenic activity of the RSF/PAM/OBC 3D printing scaffold were comprehensively investigated and verified through in vitro and in vivo studies. Results showed that the RSF/PAM/OBC (OBC-6.3 wt%) scaffold owns effective strain sensing property and desired ectopic chondrogenesis capabilities in the subcutaneous microenvironment. It could be used for reliable monitoring the joint movements, related motion amplitudes, and also promoting the cartilage specifical genes expression. These features not only confirmed the great potential of these smart scaffolds for applications in tissue reconstruction and mechanical stimulus monitoring of the corresponding tissue microenvironment, but also proved the possibility of employing various 3D printing scaffolds as flexible bioelectronics.

Cartilage Tissue Engineering in Practice: Preclinical Trials, Clinical Applications, and Prospects.

Articular cartilage defects significantly compromise the quality of life in the global population. Although many strategies are needed to repair articular cartilage, including microfracture, autologous osteochondral transplantation, and osteochondral allograft, the therapeutic effects remain suboptimal. In recent years, with the development of cartilage tissue engineering, scientists have continuously improved the formulations of therapeutic cells, biomaterial-based scaffolds, and biological factors, which have opened new avenues for better therapeutics of cartilage lesions. This review focuses on advances in cartilage tissue engineering, particularly in preclinical trials and clinical applications, prospects, and challenges.

Cartilaginous Organoids: Advances, Applications, and Perspectives

Cartilage is a nonvascular and non‐neural, mesoderm‐derived tissue. Cartilage repair, especially articular cartilage repair and reconstruction, has always been a difficult problem in bone tissue engineering. The unique biological characteristics and mechanical structure of articular cartilage make articular cartilage reconstruction a great challenge. Currently, it is extremely difficult to construct artificial cartilage tissue with all the information of natural cartilage in vitro, which greatly restricts the development of cartilage tissue engineering. Organoid technology is a booming research topic in recent years, which can mimic the complex biological characteristics of organs or tissues in vivo by constructing them in vitro through tissue engineering techniques. Cartilage tissues constructed using organoid technology may provide us with a novel tool to study cartilage development, cartilage pathological processes, and cartilage repair. This review introduces the concept and research progress of cartilage organoids and focuses on the composition and cultivation methods of cartilage organoids and application scenarios, besides giving an outlook on the limitations of present research.

Construction and tissue regeneration evaluation for mature chondrocyte/scaffold complex under optimal compression loading

The tissue engineering is a promising method for cartilage regeneration studies. The rough in vivo initial repair environment of articular cartilage is a challenge for the development of cartilage tissue engineering. Hereon, in this study, a silk fibroin/collagen type II scaffold was designed. The optimal mechanical environment for chondrocyte/scaffold complex in vitro maturation culture was determined and in vitro cultured mature artificial cartilage was evaluated for in vivo defect repair. Our research shows that the silk fibroin/collagen type II scaffold has good performance and can meet the special requirements of cartilage repair. 10 % compressive strain is the optimal compressive loading in vitro. Under optimal compression loading in vitro, chondrocytes can proliferate and grow rapidly on the scaffold to achieve better “maturation”. The in vitro cultured chondrocyte/scaffold complex effectively improves the cartilage repair effect after implantation. The compressive elastic modulus of the new tissue reached 0.682 ± 0.010 MPa after 12 weeks of repair (0.714 ± 0.011 MPa for the surrounding host cartilage). Therefore, this study not only enhance the effect of cartilage repair but also provides a promising strategy for mechanical stimulation to promote functional in situ regeneration of articular cartilage.

Recent Developments and Current Applications of Organic Nanomaterials in Cartilage Repair

Regeneration of cartilage is difficult due to the unique microstructure, unique multizone organization, and avascular nature of cartilage tissue. The development of nanomaterials and nanofabrication technologies holds great promise for the repair and regeneration of injured or degenerated cartilage tissue. Nanomaterials have structural components smaller than 100 nm in at least one dimension and exhibit unique properties due to their nanoscale structure and high specific surface area. The unique properties of nanomaterials include, but are not limited to, increased chemical reactivity, mechanical strength, degradability, and biocompatibility. As an emerging nanomaterial, organic nanocomposites can mimic natural cartilage in terms of microstructure, physicochemical, mechanical, and biological properties. The integration of organic nanomaterials is expected to develop scaffolds that better mimic the extracellular matrix (ECM) environment of cartilage to enhance scaffold-cell interactions and improve the functionality of engineered tissue constructs. Next-generation hydrogel technology and bioprinting can be used not only for healing cartilage injury areas but also for extensive osteoarthritic degenerative changes within the joint. Although more challenges need to be solved before they can be translated into full-fledged commercial products, nano-organic composites remain very promising candidates for the future development of cartilage tissue engineering.

Nondestructive assessment of tissue engineered cartilage based on biochemical markers in cell culture media: application of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy.

Tissue engineering of cartilage for tissue repair has many challenges, including the inability to assess when the developing construct has reached compositional maturity for implantation. The goal of this study was to provide a novel analytical approach to nondestructively assess tissue engineered cartilage (TEC) during in vitro development. We applied attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy to establish a quick and straightforward method to evaluate consumption of glucose and secretion of the metabolite lactate in the culture media, processes that are associated with tissue development. Using a series of standards, we showed by principal component analysis (PCA) that ATR-FTIR data was able to distinguish culture media with varying amounts of glucose and lactate. The 2nd derivative spectra displayed specific peaks of glucose at 1035 cm-1 and lactate at 1122 cm-1, and both the spectral first principal component (PC-1) scores and the 1122/1035 peak ratio very strongly correlated with the concentration of these components. TEC was prepared using chondrogenic cells grown in hydrogels, and analyzed for cell viability, distribution, and formation of proteoglycan (PG, a major cartilage protein). ATR-FTIR data of the cell culture media harvested during TEC development showed that the spectral PC-1 and the 1122/1035 peak ratio could significantly distinguish cultures with different amounts of constructs (1, 3 or 5 constructs per well) or with constructs at different developmental stages (3 or 5 weeks of culture). Interestingly, we also found that the PG content of the TEC was significantly correlated with both spectral PC-1 (r = -0.79) and the 1122/1035 peak ratio (r = 0.80). Therefore, monitoring relative glucose and lactate concentrations in cell culture media by ATR-FTIR provides a novel nondestructive approach to assess development of TEC.

Approximate Optimization Study of Light Curing Waterborne Polyurethane Materials for the Construction of 3D Printed Cytocompatible Cartilage Scaffolds.

Articular cartilage, which is a white transparent tissue with 1–2 mm thickness, is located in the interface between the two hard bones. The main functions of articular cartilage are stress transmission, absorption, and friction reduction. The cartilage cannot be repaired and regenerated once it has been damaged, and it needs to be replaced by artificial joints. Many approaches, such as artificial joint replacement, hyaluronic acid injection, microfracture surgery and cartilage tissue engineering have been applied in clinical treatment. Basically, some of these approaches are foreign material implantation for joint replacement to reach the goal of pain reduction and mechanism support. This study demonstrated another frontier in the research of cartilage reconstruction by applying regeneration medicine additive manufacturing (3D Printing) and stem cell technology. Light curing materials have been modified and tested to be printable and cytocompatible for stem cells in this research. Design of experiments (DOE) is adapted in this investigation to search for the optimal manufacturing parameter for biocompatible scaffold fabrication and stem cell attachment and growth. Based on the results, an optimal working process of biocompatible and printable scaffolds for cartilage regeneration is reported. We expect this study will facilitate the development of cartilage tissue engineering.

Optimization system of mesenchymal stem cells for tissue engineering chondrogenic differentiation

Articular cartilage defect is a common joint damage, however, due to the particularity of cartilage tissue, its repair ability is limited. Thus, articular cartilage damage often changes to more severe osteoarthritis which brings huge pain and economic burden to patients. The development of cartilage tissue engineering brings good news to these patients, but also faces great challenges. Because of the characteristics of mesenchymal stem cells(MSCs) including autologous source, amplification and cartilage differentiation potential, MSCs are often used as the seed cells of cartilage tissue engineering and got widely attention. In the commonly used treatment strategy of articular cartilage differentiated from mesenchymal cells, in vitro pre culture and differentiation showed good therapeutic effects.The mesenchymal stem cells collected from the patient were concentrated, cultured and induced differentiation in vitro, a certain number of differentiated chondrocytes were obtained, and then the cells and culture matrix were transplanted to the patient together. However, the tissue engineering cartilage obtained from mesenchymal stem cells cannot fully meet the requirements of clinical treatment. Moreover, due to the differences of disease type, degree and individuality, there are various optimized factors for the treatment of MSCs derived tissue-engineered cartilage transplantation. For the same type of disease treatment, the optimization system still has no unified recognized standard. In order to obtain better adapt to the human body and meet the clinical requirements of articular cartilage, this review focus onoptimized factors of MSCs in the treatment of orthopedic diseases, summarize and analysis the research status, and discuss the induced factorsfrom three aspects: environmental factors, scaffold selection and seed cells.It provides an idea for using mesenchymal stem cells to obtain better tissue-engineered cartilage and to establish a better optimization system.

Research advances in repair of growth plate injury

Growth plate, the developmental center of endochondral osteogenesis, can be divided morphologically and functionally into a resting zone, a proliferative zone, a prehypertrophic zone and a hypertrophic zone. Injuries to growth plate often lead to bone growth defects including limb length discrepancy and angulation deformity in children. Currently, their orthopedic corrective surgeries are invasive and limitedly effective and no effective biotherapy has been available. Previous studies on animal models of growth plate damage have investigated the related cellular and molecular events in the repair of damaged growth plates in the 4 distinct inflammatory, fibrogenic, osteogenic and remodeling phases. Related molecules involved in the regulation of the above processes, such as inflammatory cytokines tumor necrosis factor alpha, mitogenic platelet-derived growth factor and bone morphogenetic protein, are found to participate in the regulation of growth plate injury. Exploration of the mechanisms may provide new targets for biotherapy. In addition, development of cartilage tissue engineering, especially application of mesenchymal stem cells, also provides potential interventions for growth plate injury. Key words: Tissue engineering; Wounds and injuries; Bone marrow cells; Growth plate; Chondrogenesis

Advances in application of growth factors in stem cell cartilage tissue engineering

Natural degeneration or trauma of articular cartilage all can lead to its structural and functional damage. Without blood supply and nerve innervation, chondrocytes in the matrix lacunae obtain essential nutrients and excrete metabolites mainly through osmosis, finally leads to its low metabolic activity and difficulty in self-repair after injury. At present, drug conservative treatment and surgical operation are the main clinical treatment, but both of them can't meet the clinical needs well. The development of cartilage tissue engineering provides a new direction for the repair of articular cartilage injury, in which growth factors plays a very important role. Growth factors, together with seed cells and cell scaffolds, constitute the three elements for the construction of tissue-engineered cartilage. Among them, Growth factors can significantly promote cell proliferation and differentiation and induce their functions. Various growth factors synergistically mediate the differentiation of seed cells into chondrocytes. In recent years, stem cell cartilage tissue engineering developed rapidly, which has opened a new way for repair of articular cartilage damage due to its abundant cell resources, small damage to body itself, strong ability of proliferation and directional differentiation, biological repair and other prominent advantages. Different types of hydrogels and stem cells show different abilities to support chondrogenesis and require different growth factors to induce chondrocyte differentiation. Traditional growth factors for tissue engineering include transcription growth factor β, insulin-like growth factors, bone morphogenetic proteins, fibroblast growth factors and cartilage derived morphogenetic protein. Recently, some scholars found that platelet-rich plasma, platelet-rich fibrin, Kartogenin and Mechano-growth factor can also effectively induce chondrogenic differentiation of stem cells and maintain chondrocyte phenotype. In addition, some synthetic compounds such as dexamethasone and inorganic particles can also promote the differentiation of stem cells into cartilage. This article systematically summarized the new progress of the traditional growth factors, emphatically introduced the new discovered growth factors and some synthetic compounds and inorganic particles, which can induce stem cells into cartilage. Finally classified the different sources of stem cells and its suitable growth factors, and gave an outlook of the next research direction of growth factors.

The Review of Nanomaterials Inducing the Differentiation of Stem Cells into Chondrocyte Phenotypes in Cartilage Tissue Engineering.

Cartilage, as a nanostructured tissue, because of its awfully poor capacity for inherent regeneration and complete hierarchical structure, is severely difficult to regenerate after damages. Tissue engineering methods have provided a great contribution for cartilage repair. Nanomaterials have special superiority in regulating stem cell behaviors due to their special mechanical and biological properties and biomimetic characteristics. Therefore, they have been given great attention in tissue regeneration. Nanomaterials are divided into organic and inorganic nanomaterials. They provide the microenvironment to support differentiation of stem cells. Nanomaterials inducing stem cells to differentiate into chondrocyte phenotypes would be a benefit for cartilage tissue regeneration, then promoting the development of cartilage tissue engineering. In this review, we summarized the important roles of nanomaterials in chondrogenic differentiation of stem cells.

Cartilage Tissue Regeneration: The Roles of Cells, Stimulating Factors and Scaffolds.

Cartilage tissue engineering is an emerging technique for the regeneration of cartilage tissue damaged as a result of trauma or disease. As the propensity for healing and regenerative capabilities of articular cartilage are limited, its repair remains one of the most challenging issues of musculoskeletal medicine. Clinical treatments intended to promote the success and complete repair of partial- and fullthickness articular cartilage defects are still unpredictable. However, one of the most exciting theories is that treatment of damaged articular cartilage can be realized with cartilage tissue engineering. This notion has prompted tissue engineering research involving cells, stimulating factors and scaffolds, either alone or in combination. With these perspectives, this review aims to present a summary of cartilage tissue engineering including development, recent progress, and major steps taken toward the regeneration of functional cartilage tissue. In addition, we discussed the role of stimulating factors, including growth factors, gene therapies, biophysical stimuli, and bioreactors, as well as scaffolds, including natural, synthetic, and nanostructured scaffolds, in cartilage tissue regeneration. Special emphasis was placed on cell source, including chondrocytes, fibroblasts, and stem cells, as an important component of cartilage tissue engineering techniques. In conclusion, continued development of cartilage tissue engineering will support future applications for patients suffering from diseased cartilage tissue problems and osteoarthritis.

3D Printing of Cytocompatible Water-Based Light-Cured Polyurethane with Hyaluronic Acid for Cartilage Tissue Engineering Applications.

Diseases in articular cartilages have affected millions of people globally. Although the biochemical and cellular composition of articular cartilages is relatively simple, there is a limitation in the self-repair ability of the cartilage. Therefore, developing strategies for cartilage repair is very important. Here, we report on a new liquid resin preparation process of water-based polyurethane based photosensitive materials with hyaluronic acid with application of the materials for 3D printed customized cartilage scaffolds. The scaffold has high cytocompatibility and is one that closely mimics the mechanical properties of articular cartilages. It is suitable for culturing human Wharton’s jelly mesenchymal stem cells (hWJMSCs) and the cells in this case showed an excellent chondrogenic differentiation capacity. We consider that the 3D printing hybrid scaffolds may have potential in customized tissue engineering and also facilitate the development of cartilage tissue engineering.

Perspectives on Animal Models Utilized for the Research and Development of Regenerative Therapies for Articular Cartilage

Animal models are integral and indispensable for biomedical research and regenerative medicine studies, as these provide invaluable information for systemically evaluating the potential risks and efficacy of newly developed biomaterials, drugs, medical devices, and therapeutic modalities, prior to initiation of human clinical trials. Nevertheless, it is important to be aware of the unique strengths and limitations of the various different small and large animal models commonly utilized for biomedical research as well as the various challenges faced in extrapolating results acquired from animal studies and the risks of data misinterpretation. This review will thus critically examine various animal models utilized for studies on articular cartilage regeneration. Particular emphasis will be placed on comparing and analyzing the unique strengths and limitations of each animal model, with the aim of establishing principles for evaluating the suitability of different animal models for individual studies as well as for comprehensive interpretation and extrapolation of results obtained from various animal species. Additionally, this review will also discuss to evaluate animal studies with in situ imaging techniques, how the animal genome may result in variability in experimental outcomes, as well as the contribution of animal models to the development of cartilage tissue engineering.

Cartilage tissue engineering: From biomaterials and stem cells to osteoarthritis treatments

Articular cartilage is a non-vascularized and poorly cellularized connective tissue that is frequently damaged as a result of trauma and degenerative joint diseases such as osteoarthrtis. Because of the absence of vascularization, articular cartilage has low capacity for spontaneous repair. Today, and despite a large number of preclinical data, no therapy capable of restoring the healthy structure and function of damaged articular cartilage is clinically available. Tissue-engineering strategies involving the combination of cells, scaffolding biomaterials and bioactive agents have been of interest notably for the repair of damaged articular cartilage. During the last 30 years, cartilage tissue engineering has evolved from the treatment of focal lesions of articular cartilage to the development of strategies targeting the osteoarthritis process. In this review, we focus on the different aspects of tissue engineering applied to cartilage engineering. We first discuss cells, biomaterials and biological or environmental factors instrumental to the development of cartilage tissue engineering, then review the potential development of cartilage engineering strategies targeting new emerging pathogenic mechanisms of osteoarthritis.

A reaction–diffusion model to predict the influence of neo-matrix on the subsequent development of tissue-engineered cartilage

Extracellular matrix (ECM) in chondrocytes-seeded agarose aggregates to form islands of matrix. These islands need to coalesce to develop functional cartilage. Hence, macroscopic properties are determined by transport and aggregation of macromolecules at the microscale, which varies temporally and spatially. This study evaluates the importance of the mutual interaction between matrix components and matrix development. Fluorescence recovery after photobleaching measurements demonstrates that diffusivity depends on the presence and density of ECM. A reaction–diffusion model describing synthesis, transport and immobilisation of ECM predicts steep gradients in ECM around chondrocytes, resembling histology. Steric hindrance of diffusion by ECM is essential for the formation of these gradients. Finally, microscopic ECM concentration is linked with macroscopic mechanical properties. Construct softening is predicted when temporal and spatial variations in diffusivity are considered. In conclusion, non-constant diffusion renders significant effects on both the microscopic ECM development and the macroscopic mechanical properties of developing tissue-engineered cartilage.

TRENDS AND CHALLENGES OF CARTILAGE TISSUE ENGINEERING

Cartilage injuries may be caused by trauma, biomechanical imbalance, or degenerative changes of joint. Unfortunately, cartilage has limited capability to spontaneous repair once damaged and may lead to progressive damage and degeneration. Cartilage tissue-engineering techniques have emerged as the potential clinical strategies. An ideal tissue-engineering approach to cartilage repair should offer good integration into both the host cartilage and the subchondral bone. Cells, scaffolds, and growth factors make up the tissue engineering triad. One of the major challenges for cartilage tissue engineering is cell source and cell numbers. Due to the limitations of proliferation for mature chondrocytes, current studies have alternated to use stem cells as a potential source. In the recent years, a lot of novel biomaterials has been continuously developed and investigated in various in vitro and in vivo studies for cartilage tissue engineering. Moreover, stimulatory factors such as bioactive molecules have been explored to induce or enhance cartilage formation. Growth factors and other additives could be added into culture media in vitro, transferred into cells, or incorporated into scaffolds for in vivo delivery to promote cellular differentiation and tissue regeneration.Based on the current development of cartilage tissue engineering, there exist challenges to overcome. How to manipulate the interactions between cells, scaffold, and signals to achieve the moderation of implanted composite differentiate into moderate stem cells to differentiate into hyaline cartilage to perform the optimum physiological and biomechanical functions without negative side effects remains the target to pursue.

Mechanical properties of chondrocytes isolated from normal articular cartilage: experiment with rabbit knees

To measure the mechanical properties of chondrocytes of articular cartilage of knee in order to provide relevant technical parameters into the development of cartilage tissue engineering. Eight NZW rabbits were killed, and their bilateral knee joints were taken out. The articular cartilage of the left knees were used for histological study, and articular cartilage of the right knees was digested with 0.4% pronase and 0.025% collagenase type II so as to make isolation of chondrocytes. The viability rate of the isolated chondrocytes was detected by trypan blue staining. The diameters of the chondrocytes in the histological sections and single cell suspension were measured respectively. The mechanical properties of the chondrocytes were determined using micropipette aspiration technique coupled with half-space model. In the normal articular cartilage 4 structural zones were differentiated: tangential, transitional, radial, and calcified zones. The viability rate of chondrocytes was 98.2% on average after isolation. The mean diameter of the chondrocytes in the histological sections was (14.2+/-2.9) microm, not significantly different from that in the single cell suspension [(14.9+/-2.2) microm, t=1.31, P=0.19]. In response to a prescribed pressure, the chondrocytes exhibited viscoelastic solid creep behavior characterized initially by a jump in displacement followed by a monotonically decreasing rate of deformation that generally reached an equilibrium displacement. The cells were observed to deform to a length of as much as three times the radius of the micropipette without completely entering the micropipette. The cells were then extruded from the micropipette and completely recovered. The Young's modulus of the normal chondrocytes was (0.57+/-0.43) kPa, and the k1, k2, and micro of the viscoelastic parameters were (0.37+/-0.07) kPa, (0.29+/-0.04) kPa, and (6.36+/-1.12) kPa-s respectively. The k1 is positively correlated to the cell diameter (r=0.4, P=0.031). Chondrocytes from normal articular cartilage behave as a viscoelastic solid. Micropipette aspiration technique is an efficient method for the study of chondrocyte biomechanics.

602 圧縮負荷培養下の軟骨組織形成に対するスキャホールドの影響(OS5-1:組織・器官のメカノバイオロジー,オーガナイズドセッション5:組織・器官のメカノバイオロジー)

602 圧縮負荷培養下の軟骨組織形成に対するスキャホールドの影響(OS5-1:組織・器官のメカノバイオロジー,オーガナイズドセッション5:組織・器官のメカノバイオロジー)