Tissue Engineering. Part B, Reviews最新文献

Tissue engineering of oral mucosa has emerged as a promising alternative for reconstructing oral lesions. This systematic review and meta-analysis evaluated advancements in the biofabrication of artificial oral mucosa, focusing on its components, methods, and outcomes. A total of 57 studies were included, primarily preclinical in vitro research. The predominant cell sources were primary oral keratinocytes and fibroblasts, with collagen being the most utilized biomaterial. The immersion and air technique was the main biofabrication method. The meta-analysis revealed an average epithelial thickness of 73.18 μm and a maturation score of 5.13/6. In vivo studies indicated a trend toward greater epithelial stratification compared with in vitro studies. The presence of cellularized stroma, decellularized scaffolds, and custom growth factors correlated with increased epithelial thickness although without statistically significant differences. This study provides a comprehensive overview of the current state of tissue-engineered oral mucosa, highlighting its clinical potential.

Central nervous system (CNS) injury triggers a series of complex pathophysiological reactions, including neuroinflammation, oxidative stress, and DNA damage. These factors play key roles in inducing cellular senescence, thereby disrupting the balance of the microenvironment and seriously hindering tissue regeneration and repair processes. Thus, targeting cellular senescence presents a promising target for the treatment of CNS injuries. In this review, we summarized multiple potential strategies targeting senescence, including the regulation of neuroinflammation, apoptosis, oxidative stress, mitochondrial dysfunction, DNA damage, and stem cell supplementation. Furthermore, we discussed representative biomaterials with functional potential to target cellular senescence and their applications in promoting repair and regeneration in CNS injuries.

The temporomandibular joint (TMJ) comprises the mandibular condyle, the articular surface of the temporal bone, and the articular disc. The articular cartilage in the TMJ is classified as fibrocartilage, which has distinct zones: the fibrous, proliferative, mature, and hypertrophic zones. TMJ osteoarthritis (TMJOA) is a prevalent condition affecting the TMJ, with its pathogenesis involving multiple factors such as trauma, occlusal instability, joint overload, and others. Current treatment options encompass noninvasive, minimally invasive, and surgical interventions. However, no definitive cure has been found. Tissue engineering offers a novel approach to treating TMJOA by promoting cartilage repair and regeneration by constructing artificial cartilage grafts made from a combination of cells, bioactive factors (BFs), and biodegradable scaffolds. Among the scaffolds commonly used in research are hydrogels, nanoparticles, and three-dimensional-printed structures, with mesenchymal stem cells serving as the primary cell source. Additionally, exosomes and gene therapy have shown promise in TMJOA treatment. Despite significant progress, optimizing the integration of seed cells, BFs, and scaffold materials remains a critical focus for future research. This article provides an in-depth review of the latest advancements in TMJ condylar cartilage tissue engineering.

Organoid engineering is a rapidly expanding field that involves developing miniaturized, three-dimensional (3D) structures to mimic the architecture and function of real organs. It provides a powerful platform to investigate organ development, disease modeling, and personalized medicine. Recent advances in cell printing technology, also known as bioprinting, feature high-throughput potential, precise control, and enhanced reproducibility, enabling the deposition of living cells to generate complex, 3D biological structures. Cell printing with bioinks composed of cells and supportive biomaterials has been utilized to generate in vitro tissues and organs with intricate architectures and functionalities to investigate normal tissue morphogenesis and disease progression. The integration of cell printing technology and organoid engineering holds tremendous potential in biomedical research. Here, we summarize recent advances in cell printing technology in developing different organoid models, creating patient-specific tissue grafts, and utilizing these models and grafts in drug testing, as well as studying disease progression. Some of these bioprinted organoids have been utilized in clinical trials, highlighting the potential of cell printing technology in future applications in tissue and organ transplantation, as well as precision medicine. Impact Statement This article summarizes recent advances in integrating cell printing technology with three-dimensional tissue culture to develop organoid models. It discusses the advantages and limitations of three bioprinting technologies used in cell and organoid printing. The review also highlights the significant potential of cell printing technology in organoid model development and its applications in biomedical research and drug screening.

Effective wound healing hinges on a precisely orchestrated tissue remodeling process that restores both structural integrity and functionality. This review delineates the molecular mechanisms by which chitosan-based hydrogels revolutionize wound repair. Derived from natural chitin, chitosan uniquely combines robust antimicrobial, hemostatic, and biodegradable properties with the capacity to modulate critical intracellular signaling cascades-including transforming growth factor-β, mitogen-activated protein kinase, and PI3K/AKT. These dynamic interactions drive fibroblast proliferation, stimulate the strategic transition from type III to type I collagen deposition, and finely tune extracellular matrix reorganization, thereby mitigating excessive fibrosis and minimizing scar formation. Notwithstanding its considerable therapeutic promise, clinical translation of chitosan-based hydrogels is tempered by challenges in mechanical stability and controlled degradation. We propose that advanced material engineering-encompassing precision cross-linking, nanoparticle integration, and synergistic stem cell-based strategies-could surmount these limitations. This comprehensive synthesis of current molecular insights sets the stage for next-generation regenerative biomaterials, positioning chitosan-based hydrogels as a paradigm-shifting platform for achieving superior healing outcomes in complex clinical scenarios.

Intervertebral disc (IVD) herniation is a leading cause of lower back pain, with symptoms ranging from tingling to disability. Discectomy, as the most common treatment, relieves pain and reduces inflammation, but the unrevealed defect in annulus fibrosus (AF) inevitably increases the risk of herniation as high as 21%. Repair and regeneration of AF are crucial to prevent herniation and recreate healthy IVD. Mechanical repair strategies, including suture, annulus closure device, and AF patch, often fall short in material-tissue integration and tissue regeneration. Recent developments in tissue engineering integrate biological science and material engineering, mainly through hybrid hydrogels and synthetic polymer scaffolds, showing promising effects on AF repair and regeneration. This review outlines various repair strategies and their limitations. It emphasizes the need for a holistic approach considering material selection, scaffold design, and incorporating cytokines or stem cells to improve AF repair outcomes. First, advancements in electrospinning, 3D printing, and porosity engineering will be discussed to enhance the integration of scaffolds with surrounding tissue to mimic a natural AF environment. Second, the benefits of adding cells or biofactors will be reviewed to strengthen cellular interactions, migration, and differentiation of stem cells. Finally, future research will be proposed to develop innovative, multifunctional scaffolds that complement personalized medicine while also considering the impact of mechanical stimulation and scaffold porosity on cell behavior and drug delivery for more efficient repair effects.

Solid tumors represent the most common type of cancer in humans and are classified into sarcomas, lymphomas, and carcinomas based on the originating cells. Among these, carcinomas, which arise from epithelial and glandular cells lining the body's tissues, are the most prevalent. Around the world, a significant increase in the incidence of solid tumors is observed during recent years. In this context, efforts to discover more effective cancer treatments have led to a deeper understanding of the tumor microenvironment (TME) and its components. Currently, the interactions between cancer cells and elements of the TME are being intensely investigated. Remarkable progress in research is noted, largely owing to the development of advanced in vitro models, such as tumor-on-a-chip models that assist in understanding and ultimately discovering new effective treatments for a specific type of cancer. The purpose of this article is to provide a review of the TME and cancer cell components, along with the advances on tumor-on-a-chip models designed to mimic tumors, offering a perspective on the current state of the art. Recent studies using this kind of microdevices that reproduce the TME have allowed a better understanding of the cancer and its treatments. Nevertheless, current applications of this technology present some limitations that must be overcome to achieve a broad application by researchers looking for a deeper knowledge of cancer and new strategies to improve current therapies.

Meniscal damage is one of the prevalent causes of knee pain, swelling, instability, and functional compromise, frequently culminating in osteoarthritis (OA). Timely and appropriate interventions are crucial to relieve symptoms and prevent or delay the onset of OA. Contemporary surgical treatments include total or partial meniscectomy, meniscal repair, allograft meniscal transplantation, and synthetic meniscal implants, but each presents its specific limitations. Recently, regenerative medicine and tissue engineering have emerged as promising fields, offering innovative prospects for meniscal regeneration and repair. This review delineates current surgical methods, elucidating their specific indications, advantages, and disadvantages. Concurrently, it delves into state-of-the-art tissue engineering techniques aimed at the functional regenerative repair of meniscus. Recommendations for future research and clinical practice are also provided.

Bone defects because of age, trauma, and surgery, which are exacerbated by medication side effects and common diseases such as osteoporosis, diabetes, and rheumatoid arthritis, are a problem of epidemic scale. The present clinical standard for treating these defects includes autografts and allografts. Although both treatments can promote robust regenerative outcomes, they fail to strike a desirable balance of availability, side effect profile, consistent regenerative efficacy, and affordability. This difficulty has contributed to the rise of bone tissue engineering (BTE) as a potential avenue through which enhanced bone regeneration could be delivered. BTE is founded upon a paradigm of using biomaterials, bioactive factors, osteoblast lineage cells (ObLCs), and vascularization to cue deficient bone tissue into a state of regeneration. Despite promising preclinical results, BTE has had modest success in being translated into the clinical setting. One barrier has been the simplicity of its paradigm relative to the complexity of biological bone. Therefore, this paradigm must be critically examined and expanded to better account for this complexity. One potential avenue for this is a more detailed consideration of osteoclast lineage cells (OcLCs). Although these cells ostensibly oppose ObLCs and bone regeneration through their resorptive functions, a myriad of investigations have shed light on their potential to influence bone equilibrium in more complex ways through their interactions with both ObLCs and bone matrix. Most BTE research has not systematically evaluated their influence. Yet contrary to expectations associated with the paradigm, a selection of BTE investigations has demonstrated that this influence can enhance bone regeneration in certain contexts. In addition, much work has elucidated the role of many controllable scaffold parameters in both inhibiting and stimulating the activity of OcLCs in parallel to bone regeneration. Therefore, this review aims to detail and explore the implications of OcLCs in BTE and how they can be leveraged to improve upon the existing BTE paradigm.

The urethral reconstruction using tissue engineering is a promising approach in clinical and preclinical studies in recent years. Generally, regenerative medicine comprises cells, bioactive agents, and biomaterial scaffolds to reconstruct tissue. For the restoration of extended urethral injury are incorporated autologous grafts or flaps from the skin of the genital area, and buccal mucosa are also utilized. However, biomaterial grafts with cells or growth factors are investigated to enhance these grafts. Natural and synthetic biomaterials were investigated for preclinical studies in the form of decellularization tissues, nanofiber/microfiber, film, and foam grafts that determined safety and efficiency. In this regard, skin grafts, bladder epithelium, buccal mucosa, small intestinal submucosa, tissue-engineered buccal mucosa, and polymeric nanofibers in clinical trials were examined, and promising and diverse outcomes were acquired. Even though one of the challenges of the reconstruction of the urethra is resistance to urine pressure and its ability to be sutured, it could be solved by the proper adjustment of the physicochemical characteristics of the graft. Urethral engineering faces challenges due to necrosis caused by a lack of angiogenesis and fibrosis, which require further investigation in future studies.