Tissue Engineering. Part B, Reviews最新文献

Autologous fat grafting has been widely adopted in cosmetic and reconstructive procedures recently. With the emerging of negative-pressure-assisted liposuction system, the harvesting process of fat grafting is more standardized, controllable, and efficient. Each component in the system could influence the biomechanical environment of lipoaspirate. Several reviews have studied the impact of negative pressure on fat regeneration. As the initial part of the harvesting system, cannulas possess their unique mechanical parameters and their influence on lipoaspirate biomechanical characters, biological behaviors, and regeneration patterns remains unclear. Basic in vivo and in vitro studies have been performed to determine the possible mechanisms. Instant in vivo studies focus on adipocytes, stromal vascular fraction cells, fat particles, and growth factors, while in vivo grafting experiments analyze the graft retention rate and histology. Understanding the different regeneration patterns of lipoaspirate and the mechanisms behind may facilitate the choice of harvesting cannulas in clinical practice.

Three-dimensional printing (3DP) strategies in the field of meniscus and articular disc repair and regeneration have recently garnered significant attention. However, a comprehensive bibliometric assessment to evaluate the scientific progress in this area is lacking. This research aims to explore the development, key areas of focus, and new directions in 3DP techniques for meniscus and articular disc over the last 15 years, considering both structural and temporal perspectives. Academic papers on 3DP approaches for the repair and regeneration of these tissues were retrieved from the Web of Science Core Collection. Bibliometric analysis tools such as R software, CiteSpace, and VOSviewer were utilized to examine the historical patterns, topic evolution, and emerging trends in this domain. For the past 15 years, there has been a steady increase in scholarly attention toward 3DP for the repair of meniscus and articular discs, along with a notable expansion in impactful scientific partnerships. The timeline analysis of references indicates that 3DP methodologies have predominantly shaped the research agenda over the last 10 years, retaining their significance amid annual fluctuations in the focus of citations. Four emerging research subfields were identified through keyword clustering: "mesenchymal stem cells," "fabrication," "scaffolds," and "cartilage." Additionally, we mapped out the top 13 key clusters based on CiteSpace. The time zone view of keyword analysis identified three emerging research niches: "anti-inflammatory and antioxidant," "chondrogenic differentiation," and "silk-based biomaterial-ink." The insights gleaned from these bibliometric studies highlight the current state and trends in 3DP research for meniscus and articular disc, potentially assisting researchers in identifying key focal points and pioneering innovative research directions within this area.

Amniotic membrane transplantation is commonly employed in ophthalmology to mend corneal epithelial and stromal defects. Its effectiveness in restoring the ocular surface has been widely acknowledged in clinical practice. Nevertheless, there is ongoing debate regarding the comparative effectiveness of using fresh amniotic membranes versus preserved ones. The objective of this meta-analysis was to ascertain whether there is a disparity in the effectiveness of fresh versus preserved amniotic membrane in the restoration of the ocular surface in clinical practice. The study utilized the following keywords: "fresh amniotic membrane," "preserved amniotic membrane," "amniotic membrane transplantation," and "ocular surface reconstruction." The study conducted a comprehensive search for relevant studies published until April 18, 2024. Seven different databases, namely PubMed, Web of Science, Embase, Cochrane, China Knowledge, China Science and Technology Journal VIP database, and Wanfang database, were utilized. The search was performed using the keywords "fresh amniotic membrane," "preserved amniotic membrane," "amniotic membrane transplantation," and "ocular surface reconstruction." The process of literature review and data extraction was carried out separately by two researchers, and all statistical analyses were conducted using Review Manager 5.4.1. The final analysis comprised nine cohort studies, encompassing a total of 408 participants. The statistics included six outcome indicators: visual acuity (relative risk [RR] = 1.07, 95% confidence interval [CI] = 0.93-1.24, I² = 0); amniotic membrane viability (RR = 1.00, 95% CI = 0.93-1.08, I² = 0); ocular congestion resolution (RR = 1.11, 95% CI = 0.97-1.26, I² = 0); fluorescent staining of amniotic membranes on the second day after the operation (RR = 1.31, 95% CI = 0.80-2.14, I² = 11); postoperative recurrence rate (RR = 1.01, 95% CI = 0.50-2.03, I² = 0); and premature lysis of amniotic membrane implants (RR = 0.96, 95% CI = 0.49-1.88, I² = 0). The findings indicated that there was no statistically significant disparity between fresh and preserved amniotic membranes across any of the measured variables. There is no substantial disparity in the effectiveness of fresh and preserved amniotic membrane transplants in restoring the ocular surface, and both yield favorable and consistent outcomes.

In the realm of dental tissue regeneration research, various constraints exist such as the potential variance in cell quality, potency arising from differences in donor tissue and tissue microenvironment, the difficulties associated with sustaining long-term and large-scale cell expansion while preserving stemness and therapeutic attributes, as well as the need for extensive investigation into the enduring safety and effectiveness in clinical settings. The adoption of artificial intelligence (AI) technologies has been suggested as a means to tackle these challenges. This is because, tissue regeneration research could be advanced through the use of diagnostic systems that incorporate mining methods such as neural networks (NN), fuzzy, predictive modeling, genetic algorithms, machine learning (ML), cluster analysis, and decision trees. This article seeks to offer foundational insights into a subset of AI referred to as artificial neural networks (ANNs) and assess their potential applications as essential decision-making support tools in the field of dentistry, with a particular focus on tissue engineering research. Although ANNs may initially appear complex and resource intensive, they have proven to be effective in laboratory and therapeutic settings. This expert system can be trained using clinical data alone, enabling their deployment in situations where rule-based decision-making is impractical. As ANNs progress further, it is likely to play a significant role in revolutionizing dental tissue regeneration research, providing promising results in streamlining dental procedures and improving patient outcomes in the clinical setting.

The increasing number of elderly people across the globe has led to a rise in osteoporosis and bone fractures, significantly impacting the quality of life and posing substantial health and economic burdens. Despite the development of tissue-engineered bone constructs and stem cell-based therapies to address these challenges, their efficacy is compromised by inadequate vascularization and innervation during bone repair. Innervation plays a pivotal role in tissue regeneration, including bone repair, and various techniques have been developed to fabricate innervated bone scaffolds for clinical use. Incorporating neural-related cells and delivering neurotrophic factors are emerging strategies to accelerate bone regeneration through innervation. However, research into neurogenic cell sources remains limited. Meanwhile, neural stem/progenitor cells (NSPCs) are emerging as promising cells for treating neurodegenerative disorders and spinal cord injuries due to their multifunctional capacity in promoting angiogenesis, neurogenesis, and immunomodulation, making them promising candidates for achieving innervation in bone substitutes. In this review, we discuss the regenerative potential of NSPCs in tissue regeneration. We propose their feasibility for bone therapy through their secreted exosomes during traumatic brain injury, contributing to the acceleration of bone healing. Additionally, we discuss the essential neurotrophic factors released from NSPCs and their osteogenic properties. This review emphasizes the necessity for further investigation of the role of NSPCs in bone regeneration.

Photoaged skin features an appearance of premature aging induced by external factors, mainly ultraviolet (UV) irradiation. Visible aging signs and increased susceptibility to skin-related diseases triggered by UV irradiation have raised widespread concern. As a critical component of human skin, the extracellular matrix (ECM) provides essential structural, mechanical, and functional support to the tissue. Consequently, UV-induced ECM deterioration is a major contributor to photoaging. This review begins by analyzing the structural and functional changes between healthy and photoaged skin in prominent ECM components, including collagens, glycosaminoglycans (GAGs), proteoglycans, basement membrane proteins, and elastic fibers. Furthermore, we explore the key mechanisms driving ECM deterioration in response to UV irradiation, focusing on mitogen-activated protein kinase/matrix metalloproteinase and transforming growth factor-β/Smad signaling pathways, as well as the synthesis and degradation of GAGs. A comprehensive understanding of these changes and underlying mechanisms is crucial for elucidating the biological influence of UV on the ECM, ultimately providing more reliable evidence for the prevention and treatment of skin photoaging.

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.

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.

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.

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.