Tissue Engineering. Part B, Reviews最新文献

Advancement in nanotechnology has rapidly led to the widespread applications of varied nanoparticles (NPs) in day-to-day life. Among them, metal and metal oxide-based NPs are significant due to their unique physicochemical properties and diversified applications. However, these properties that make them valuable can also pose unexpected, noxious threats to various organs in the human body. That is why a comprehensive consideration of NP toxicity is important for exploring their safer and effective use in varied biomedical applications. This review aims to compile current knowledge about the pulmonary toxicity of silver, zinc oxide, copper oxide, and aluminum oxide-based NPs, with a focus on the physicochemical properties affecting their pulmonary toxicity and its mechanisms. However, these studies employ high doses that are somewhat less relevant to human inhalation exposures, but with an understanding of these aspects, we can better navigate the challenges and concerns posed by metal-based NPs and work toward safer biomedical applications.

The thyroid gland is an endocrine organ responsible for production of triiodothyronine and thyroxine, essential hormones that regulate human metabolism. A wide range of conditions can impair its function, leading to potential life-threatening consequences such as myxedema coma. The standard treatment for hypothyroidism is lifelong levothyroxine supplementation, which, despite being a significant therapeutic breakthrough, has notable limitations and does not fully restore quality of life for many patients. Biomimetic thyroid gland has emerged as a promising alternative treatment strategy for patients with hypothyroidism. Most research to date has focused on generating thyroid organoids from primary thyroid cells or stem cells. However, there is growing interest in other approaches, including the use of biomaterials, bioreactors, and 3D bioprinting as potential alternatives or supplementary technologies to the organoids. While in vitro and preclinical studies have shown encouraging results, clinical application of biomimetic thyroid gland requires further studies in several key areas, including long-term functional validation, studies on large animal models, immunological compatibility and scaffold biodegradation, and absence of standardized good manufacturing practice (GMP)-compliant production protocols.

Breast cancer remains the most commonly diagnosed malignancy among women worldwide. Standard treatment often involves mastectomy, followed by chemotherapy and/or radiation. Approximately 40% of patients undergo breast reconstruction to address the physical and psychological effects of tissue loss. Since the first autologous breast reconstruction described in 1887, both autologous and alloplastic techniques have evolved significantly to improve patient outcomes. However, current approaches are limited by issues such as the inability to restore biological breast function, suboptimal tissue integration, and concerns over long-term implant viability. Tissue engineering has emerged as a promising field capable of overcoming these limitations. Since the 1990s, advances in biomaterials, stem cell research, and regenerative strategies have enabled the development of vascularized, patient-specific constructs with potential applications in both structural and functional breast reconstruction. This review provides a comprehensive overview of the evolution of breast reconstruction techniques and the integration of tissue engineering into the field. Particular emphasis is placed on tissue engineering's role in enhancing breast cancer treatment and diagnosis while also exploring future directions toward functional restoration, including lactation.

Pelvic organ prolapse (POP) is a common yet complex condition affecting women, characterized by the descent of pelvic organs due to weakened pelvic floor structures. While several treatment strategies exist, their efficacy is often limited, and complications such as surgical failure or recurrence can hinder long-term success. Hydrogels, due to their unique properties such as high-water content, biocompatibility, and flexibility, offer promising potential in the management of POP. This review summarizes various animal models of POP including abdominal wall weakness model, sustained pressure method (vaginal ball stretching), ovariectomy (OVX) model, and gene knockout model. This review further provides a comprehensive overview of the role of hydrogels in POP, highlighting their applications in tissue engineering, drug delivery, and as coatings or injectable materials for prolapsed organs. Furthermore, the challenges in their development were discussed, including material selection, degradability, mechanical properties, and long-term biocompatibility. The strategies to optimize hydrogel performance to better meet clinical needs, with an emphasis on personalization and multifunctionality, were outlined. In conclusion, while hydrogels offer significant promise, further research into their design, application methods, and clinical outcomes is crucial to fully realize their potential in the treatment of POP.Impact StatementThis review highlights the transformative potential of hydrogels in treating pelvic organ prolapse, a condition with limited long-term therapeutic success. By systematically analyzing animal models and exploring hydrogel applications in tissue repair and drug delivery, it identifies critical challenges and future directions. The insights offered lay the groundwork for personalized, multifunctional hydrogel systems, guiding future research and accelerating clinical translation.

Recent advancements in Parkinson's disease (PD) research have both enriched our pathophysiological understanding and challenged conventional therapeutic dogmas. The emerging application of ectodermal mesenchymal stem cells (EMSCs) derived from the cranial neural crest for neuronal regeneration represents a paradigm-shifting therapeutic modality, diverging fundamentally from traditional dopamine-replacement strategies. However, the fundamental mechanisms responsible for their remarkable neurorestorative potential in PD pathophysiology are still not fully understood. This comprehensive review synthesizes current evidence on the pleiotropic therapeutic capacities of EMSCs, focusing on their ectoderm-derived molecular signatures. Central to this review are developmental insights into nasal mucosa-derived EMSCs, particularly their Nestin⁺ identity, elevated connexin43, niche-specific paracrine activity, and robust dopaminergic differentiation capacity, to guide therapeutic translation for PD. Through systematic interrogation of nasal mucosa-derived EMSC physiology, we aim to establish an evidence-based platform for developing targeted neuroregenerative therapies.

Aging is a gradual process leading to the decline of physiological functions across cells, organs, tissues, systems, and the surrounding microenvironment, particularly affecting the musculoskeletal system. Bone aging often presents with osteoporosis and impaired osteogenic niche, thereby increasing fracture risk and decreasing regenerative capacity. Therefore, bone aging and osteoporotic bone defects have become a significant challenge in clinical practice. Tissue-engineered scaffolds are of significant importance in managing osteoporotic bone defects by providing mechanical support, facilitating bone regeneration and repair. They can also serve as a vehicle for drugs or factors for osteoporosis management, thereby enabling localized targeted therapy. The local release of active pharmaceutical agents for the treatment of osteoporosis via biomaterials could serve to reduce the occurrence of systemic side effects, while improving the local aging metabolic microenvironment and immune microenvironment. This review presents a comprehensive discussion of the mechanisms and treatment methods of osteoporosis. The scaffolds used for osteoporotic bone defects are also reviewed. We conducted an in-depth analysis of the impact of diverse preparation techniques and modifications on the osteogenic properties of the scaffolds, and reviewed different materials of drug delivery scaffolds for the repair of osteoporotic bone defects. Finally, we put forward our scientific concept regarding the treatment of bone aging and osteoporotic bone defects. We hope to provide a theoretical basis and research ideas for further in-depth studies on treating osteoporosis and bone aging.

As miniature, three-dimensional emulates of individual human organs generated in vitro, organoids are increasingly recognized as complex, humanized models of development, disease, diagnostics, and drug discovery. Organoids exhibit organ-specific architecture, function, and multicellular composition, can be infinitely derived from pluripotent stem cells, and can be further directed toward organoids of the endocrine or exocrine pancreas. Pancreatic endocrine organoids are rapidly redefining diabetes therapies due to their ability to recapitulate glucose-responsive insulin secretion. Conversely, there is less focus on pancreatic exocrine organoids, which possess untapped potential for investigating disorders such as cancer and cystic fibrosis. This review first summarizes human pancreatic organogenesis to contextualize relevant differentiation pathways, then details protocols that guide human pluripotent stem cells through key developmental stages. Methods to enhance cellular maturation and establish higher-performing end products, as well as the therapeutic value of different pancreatic genres, are assessed. Furthermore, crucial gaps are identified, including limited insight into non-beta-endocrine cells, progenitor lineage bias, and off-target differentiation. By chronicling the advancements of all pancreatic organoid classes, the importance of creating more intricate constructs is underscored, which could lead to their broader application.

Peripheral nerve injuries, though rarely fatal, can lead to sensory and motor deficits and neuropathic pain, significantly lowering patients' quality of life. Thus, it is crucial to explore potential treatments that can promote the regeneration of injured sciatic nerves. Currently, nerve anastomosis is performed between the two ends for short-gap nerve defects, while long-gap nerve defects require the use of nerve conduits, scaffolds, and nerve grafts. In terms of neural tissue engineering, identifying suitable biomaterials remains a key challenge. Polylactic acid (PLA) is a synthetic, biodegradable polymer with excellent processability, allowing it to be manufactured into various structures. Its mechanical properties, biodegradability, biomineralization capacity, and antibacterial properties make it a promising material for neural tissue engineering applications. In this work, we first introduce the physical and chemical properties, as well as the synthesis routes, of PLA and further elucidate the effect of various additives on its mechanical properties. Finally, we critically evaluate PLA-based strategies-including scaffolds, nerve conduits, drug delivery carriers, films, and microspheres-for promoting peripheral nerve regeneration. Taken together, PLA and its derivatives have a promising future in neural tissue engineering, with application methods and scenarios set to become more diverse.

The development of effective biomaterials for bone defect repair remains challenging due to limitations in mechanical properties, bioactivity, and degradation characteristics. We summarize recent progress in synthetic bone materials, including metals, ceramics, and polymer composites, critically analyzing their clinical strengths and weaknesses. This review presents the fabrication of a new generation of mineralized collagen materials through biomimetic mineralization, demonstrating that their composites exhibit promising clinical application potential. Inspired by the hierarchical architecture of natural bone, a multiscale cascade regulation strategy is further proposed to achieve multidimensional mimicry in composition, structure, mechanical properties, and biological functionality. Special attention is given to multidimensional biomimetic strategies integrating nano-scale molecular self-assembly, electrospinning, and macroscale pressure-driven fusion to construct artificial lamellar bone and artificial cortical bone. In summary, this article provides valuable insights into understanding artificial bone repair materials and their development trends, offering significant guidance for the development of new degradable biomimetic artificial compact bone materials.

The musculoskeletal system, essential for mobility, structural support, and organ protection, is frequently compromised by trauma, degenerative diseases, or tumors, profoundly impacting patients' quality of life. Adhesive hydrogels have emerged as pivotal biomaterials for orthopedic therapies, offering localized treatment with enhanced biocompatibility, tunable mechanics, and sustained bioactive delivery. While systemic drug administration often suffers from off-target effects, adhesive hydrogels enable precise tissue integration and microenvironmental modulation, addressing challenges such as infection control, tissue regeneration, and mechanical reinforcement. However, achieving optimal adhesion strength, dynamic mechanical matching, and selective tissue targeting remains a critical hurdle. Innovative strategies, including dynamic covalent bonds, stimuli-responsive networks, and multifunctional hybridization, have expanded hydrogel applications in diabetic wound healing, load-bearing bone repair, and spinal cord regeneration. For instance, injectable hydrogels with wet adhesion capabilities facilitate minimally invasive delivery, while drug-eluting systems localize chemotherapeutics to tumor sites, reducing systemic toxicity. Despite these advances, scalability, long-term stability, and clinical translation require further exploration. This review systematically examines the design principles, functional mechanisms, and therapeutic applications of adhesive hydrogels in orthopedics, emphasizing their role in bridging biomechanical demands with biological regeneration. We envision that interdisciplinary innovation in smart hydrogels will unlock personalized solutions, transforming the landscape of precision orthopedic medicine.