Journal of Tissue Engineering最新文献

[This retracts the article DOI: 10.1177/20417314221149207.].

Articular cartilage plays a crucial role in reducing friction between bones and enabling movements; however, it is frequently degraded due to persistent joint stress, aging, and osteoarthritis. As its self-repair ability is limited, various cell-based therapeutic strategies have been developed for cartilage regeneration. Conventional two-dimensional (2D) cell cultures inadequately replicate the complex intercellular interactions of native cartilage. In contrast, three-dimensional (3D) cell spheroid cultures can more accurately mimic in vivo cellular physiology, offering superior regenerative potential via improved cell-cell and cell-matrix interactions. These interactions can be enhanced with biomaterials to form composite spheroids, which exhibit substantial potential for improving cartilage regeneration and attenuating osteoarthritis progression in vivo by promoting cell survival and tissue integration. This review highlights current strategies for developing biomimetic composite spheroid systems, including spheroid encapsulation, scaffold incorporation, and 3D bioprinting. Furthermore, we discuss their advantages, translational potential for in vivo cartilage repair, and the challenges and future directions in cartilage tissue engineering.

Cell sheet engineering provides a scaffold-free strategy for fabricating cohesive tissue constructs, but challenges remain in maintaining structural integrity and mimicking complex tissue architectures. This study demonstrated perfluorodecalin-based liquid-liquid interfaces, known for their inertness and stability, as a simple, and efficient platform for fabricating cell sheets. Using single cells, spheroids, and their combination, we evaluated methods to enhance sheet formation. Single cells formed cohesive sheets at high densities (4 × 10⁶ cells/well) but exhibited limited long-term stability due to nutrient constraints. Spheroids formed robust sheets at lower densities (2 × 10⁶ cells/well), whereas higher densities impaired fusion. The mixed approach combined the advantages of both, improving uniformity, mechanical stability, and spheroid fusion, while mimicking muscle-like structures with vascular networks. Additionally, the cell sheets retained adipogenic and chondrogenic differentiation potential, highlighting their functional viability. These findings establish liquid interfaces as a practical and versatile platform for tissue engineering, regenerative medicine, and in vitro modeling.

In the field of tissue reconstruction, the development and improvement of suitable bone grafts is of increasing importance. The implementation of bone banks enables the international distribution of suitable allografts that can be used for defect reconstruction. Currently used procedures have significant drawbacks, especially regarding biomechanical and structural properties. These can be overcome by using the technique of high hydrostatic pressure (HHP) processing. To date, little is known about the impact of HHP protocol alterations including pressure-transmitting medium or temperature regarding bone graft integrity. Data of the present study show that a low-temperature and medium-pressure treatment using isotonic sodium chloride solution as the pressure-transmitting medium generated devitalized bone tissue with preserved extracellular matrix. Specifically, efficient devitalization of human primary osteoblasts (hOBs) was found starting from 150 MPa with cell death being a complex interaction between different mechanisms. Furthermore, protein denaturation in response to HHP treatment that was predominantly observed at 600 MPa led to non-significant impairment of biomechanical properties. Effects of HHP treatment on the bone tissue did not lead to any noticeable compromise in biocompatibility. Accordingly, the presented protocol may be applied as a medical device to improve the outcome of patients undergoing bone defect reconstruction with allogenic grafts.

Inflammatory cytokines play a crucial role in the inflammatory response, and their aberrant expression and overproduction are closely associated with the development of many diseases. However, traditional inflammation treatment strategies are often accompanied by serious side effects, limiting their widespread use. In recent years, hydrogel, as a material with a three-dimensional network structure, good biocompatibility and modulability, has great potential for trapping and neutralizing inflammatory factors. Hydrogels can capture and neutralize inflammatory cytokines through various mechanisms such as electrostatic interactions, coupling with cytokine antibodies or binding nanoparticles. In addition, hydrogel microspheres, an important form of hydrogels, have excellent broad-spectrum binding of inflammatory cytokines in combination schemes with cell membranes. This article reviews recent research advances in hydrogel capture and neutralization of inflammatory cytokines, discussing the advantages of various mechanisms and their applications in different diseases. Overall, we believe that hydrogels are expected to further advance the development of therapeutic modalities for inflammatory diseases in the future.

Xenogeneic tumour origin and batch-to-batch variability of Engelbreth-Holm-Swarm sarcoma tumour cell-derived hydrogels (Matrigel, Cultrex) limit the biomedical application of organoids in tissue engineering. The gelatin-methacryloyl (GelMA) hydrogels represent a defined, tunable, and GMP-friendly alternative, but they are rarely studied as alternative to Matrigel. Here, we studied effects of mechanical properties of GelMA and addition of laminin-111 on encapsulation and growth of small intestinal organoids. GelMA-embedded organoids displayed polarity reversion, resulting in apical-out and apical-basal phenotypes, independent from the matrix stiffness. Addition of laminin-111 softened hydrogels and also resulted in a partial restoration of the basal-out phenotype. Interestingly, despite the incomplete polarity restoration, GelMA-organoids still showed minor growth. GelMA stiffness and concentration influenced the transition from 3D to 2D organoid cultures. Collectively, our study confirms that tuning of GelMA mechanical properties alone cannot recapitulate the basal membrane matrix. However, controlled polarity reversion offers a tool for engineering organoids and enabling apical membrane access.

Triple-negative breast cancer (TNBC) is highly aggressive and lacks targeted therapies, posing a major challenge in oncology. Traditional two-dimensional (2D) cell cultures fail to capture the tumor microenvironment's complexity, whereas three-dimensional (3D) cultures provide a more accurate model of tumor biology. We developed an advanced 3D culture system for TNBC cell lines BT-20 and MDA-MB-231, enhancing the hanging-drop method with Matrigel to restore essential extracellular matrix interactions. Confocal imaging showed MDA-MB-231 cells forming clusters typical of aggressive carcinoma, while BT-20 cells organized into duct-like structures. Molecular analysis of PI3K and β-catenin target genes revealed distinct expression patterns, with PI3K overexpressed and β-catenin downregulated in 3D cultures. Moreover, β-catenin distribution in the 3D cell culture closely resembles its pattern in tissue. These findings underscore the value of 3D models in understanding TNBC progression and in supporting the exploration of novel therapeutic strategies.

The development of immunocompetent skin models marks a significant advancement in in vitro methods for detecting skin sensitizers while adhering to the 3R principles, which aim to reduce, refine, and replace animal testing. This study introduces for the first time an advanced immunocompetent skin model constructed entirely from induced pluripotent stem cell (iPSC)-derived cell types, including fibroblasts (iPSC-FB), keratinocytes (iPSC-KC), and fully integrated dendritic cells (iPSC-DC). To evaluate the skin model's capacity, the model was treated topically with a range of well-characterized skin sensitizers varying in potency. The results indicate that the iPSC-derived immunocompetent skin model successfully replicates the physiological responses of human skin, offering a robust and reliable alternative to animal models for skin sensitization testing, allowing detection of extreme and even weak sensitizers. By addressing critical aspects of immune activation and cytokine signaling, this model provides an ethical, comprehensive tool for regulatory toxicology and dermatological research.

Magnesium-degradable implants have excellent mechanical and osteogenic properties for temporary orthopedic use but are underutilized due to insufficient methods to monitor implant osseointegration and tissue healing. This study evaluated the use of circulatory biomarkers to monitor the bilateral implantation of a Mg-alloy in rats' femurs. A total of 16 biomarkers were measured from plasma samples collected at multiple timepoints up to 90 days post-implantation. Mg-alloy, Ti-alloy, and Sham (noncritical bone defect) groups were followed with computed tomography, histological, and SEM-EDX analysis. The Sham group showed higher DKK1, OPG, VEGF, and KIM-1 levels than implanted groups. The Mg-alloy group had delayed bone regeneration due to gas release but demonstrated active regeneration up to 180 days and superior osseointegration. Elevated IL-10 and reduced FGF23 at day 28 correlated with accelerated implant degradation. These results underline the complex interactions between biomaterials and biological systems in orthopedic applications and show the value of circulating markers to follow-up implantation.

No permanent cure exists for salivary gland (SG) damage and consequent xerostomia (dry mouth) in patients undergoing radiotherapy for head and neck cancers. The lack of commercially available healthy human SG-derived cell lines has hindered in vitro studies of radiation-induced glandular injury. In this study, we successfully immortalized and characterized two novel human major SG-derived cell lines. Leveraging these cell lines and hyaluronic-acid hydrogels, we bioengineered distinct multicellular SG spheroids and microtissues expressing key acinar, ductal, myoepithelial, and mesenchymal cell markers in long-term cultures. Further, using this platform, we developed a proof-of-concept radiation injury model, demonstrating spheroid disruption characterized by actin depolymerization, DNA damage, apoptosis, and loss of SG-specific markers following radiation exposure. Notably, these detrimental effects were partially mitigated with a radioprotective agent. Our findings demonstrate that the bioengineered SG spheroids provide a scalable and versatile platform with significant potential for disease modeling and drug testing, thereby accelerating the development of targeted therapies for radiation-induced xerostomia.