Tissue Engineering. Part B, Reviews最新文献

Osteoporosis, affecting the entire skeletal system, can cause bone mass to diminish, thereby reducing bone strength and elevating fracture risk. Fracture nonunion and bone defects are common in patients with fractures, and pain and loss of function may cause serious distress. The search for a new therapeutic strategy is essential because of the limited therapeutic options available. Bone marrow mesenchymal stem cells (BMSCs) are crucial for bone metabolism and development due to their high self-renewal capabilities. Wnt signaling is a key pathway that plays a significant role in bone formation by regulating the differentiation of BMSCs. Therefore, the osteogenic differentiation of BMSCs can be regulated by activating Wnt signaling as an idea for bone tissue repair. In this review, we systematically compile and analyze the roles of various drugs, biomolecules, exosomes, and biomaterials in influencing the Wnt/β-catenin signaling pathway during the osteogenic differentiation of BMSCs. It is also discussed how these factors impact on BMSCs and the Wnt/β-catenin pathway. Finally, we also present recent advances in combining bone regeneration materials through these factors, which will help subsequent clinical treatment and translation.

Myofascial pain syndromes, stemming from trigger points within the muscles, represent a prevalent cause of localized or generalized pain in clinical practice. They have a high incidence rate and currently lack specific curative methods. Trigger point injection therapy is the most popular clinical approach, focusing primarily on these trigger points. Injectable drugs like glucose, normal saline, local anesthetics, botulinum toxin type A, steroid preparations, and platelet-rich plasma are available for this purpose. This treatment is advantageous due to its low cost and minimally invasive nature, showing promising results in early clinical use. However, the lack of consensus on the optimal injectable substance presents a significant challenge in clinical practice. This article reviews the progress in clinical research on trigger point injection therapy and drug efficacy, along with precautions for drug administration in managing myofascial pain syndrome. It aims to offer fresh perspectives for future studies and establish a theoretical foundation for treating and caring for myofascial pain syndrome.

Tissue and organ dysfunction are major causes of worldwide morbidity and mortality with all medical specialties being impacted. Tissue engineering is an interdisciplinary field relying on the combination of scaffolds, cells, and biologically active molecules to restore form and function. However, clinical translation is still largely hampered by limitations in vascularization. Consequently, a thorough understanding of the microvasculature is warranted. This review provides an overview of (1) angiogenesis, including sprouting angiogenesis, intussusceptive angiogenesis, vascular remodeling, vascular co-option, and inosculation; (2) strategies for vascularized engineered tissue fabrication such as scaffold modulation, prevascularization, growth factor utilization, and cell-based approaches; (3) guided microvascular development via scaffold modulation with electromechanical cues, 3D bioprinting, and electrospinning; (4) surgical approaches to bridge the micro- and macrovasculatures in order to hasten perfusion; and (5) building specific vasculature in the context of tissue repair and organ transplantation, including skin, adipose, bone, liver, kidney, and lung. Our goal is to provide the reader with a translational overview that spans developmental biology, tissue engineering, and clinical surgery.

Epicatechin (EC)-based derivatives have garnered significant attention for their powerful antioxidant, anti-inflammatory, anticancer, and antibacterial properties, all of which are attributed to the phenolic hydroxyl groups in their structure. These compounds are promising in regenerative medicine, particularly as bioactive components in scaffolds. This review provides an in-depth analysis of the mechanisms by which EC-based materials enhance tissue repair, examining their application in various scaffold forms, such as hydrogels, nanoparticles, and nanofibers. This study also addresses the challenges of stability and bioavailability associated with ECs and proposes encapsulation techniques to overcome these barriers. The potential clinical benefits of ECs in regenerative medicine and their role in fostering advancements in tissue engineering are discussed, making this review a valuable resource for guiding future studies on the integration of ECs into clinical practice.

Conditions such as congenital abnormalities, cancer, infections, and trauma can severely impact the integrity of the auricular cartilage, resulting in the need for a replacement structure. Current implants, carved from the patient's rib, involve multiple surgeries and carry risks of adverse events such as contamination, rejection, and reabsorption. Tissue engineering aims to develop lifelong auricular bioimplants using different methods, different cell types, growth factors and maintenance media formulations, and scaffolding materials compatible with the host. This review aims to examine the progress in auricular bioengineering, focusing on improvements derived from in vivo models and clinical trials, as well as the author's suggestions to enhance the methods. For this scope review, 30 articles were retrieved through Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, plus 6 manually selected articles. The methods reported in the articles were categorized into four levels according to the development phases: source of cells, cell media supplementation, scaffold, or scaffold-free methods, and experimental in vivo or clinical approaches. Many methods have demonstrated potential for the development of bioimplants; four clinical trials reported a structure like the external ear that could be maintained after overcoming post-transplant inflammation. However, several challenges must be solved, such as obtaining a structure that accurately replicates the shape and size of the patient's healthy contralateral auricle and improvements to avoid immunological rejection and resorption of the bioimplant.

All inorganic nanomaterials such as gold, silica, and cobalt oxide nanoparticles are transforming tissue engineering by providing enantioselective properties with unique characteristics that are mimicking the chirality of biological systems, allowing the precise modulation of cellular behaviors like differentiation and alignment. It is essential for the regeneration of complex tissues such as bone, cartilage, and neural networks, but their clinical application is being obstructed by considerable challenges such as the inability to sustain consistent chirality during synthesis. There are limited means to characterize their molecular structure, the high cost of their production, which constrains their scalability, and the long-term biocompatibility. There are different concerns of these materials in physiological environments, which call for novel solutions such as machine learning-aided synthesis, bioinspired mineralization, and interfacing with cutting-edge technologies such as 3D and 4D bioprinting to design biomimetic scaffolds that facilitate enhanced tissue regeneration. The personalized strategies that are modifying nanomaterial properties to match the distinct requirements of individual patients have the promise of enhancing therapeutic outcomes, and collaborations among materials science, bioengineering, and clinical expertise are needed to standardize protocols, overcome regulatory barriers, and tap the full potential of these nanomaterials. This review is hence a critical appraisal of their revolutionary potential, present limitations, and future promise in enhancing regenerative medicines. [Figure: see text].

Fecal incontinence (FI) severely affects physical and psychological well-being. Artificial anal sphincters (AASs) provide a reconstructive option for patients with severe sphincter damage or congenital dysfunctions, but their clinical application is often limited by complications stemming largely from poor biomechanical compatibility with host tissues. This review examines the physiological mechanisms of defecation as the basis for bionic AAS design and classifies existing devices into two main types: those simulating anorectal angle regulation and those mimicking direct sphincter occlusion. A comparative analysis reveals distinct biomechanical failure modes associated with each approach: angle-modulating devices face challenges like tissue hyperplasia around moving parts, while direct occlusion devices, particularly high-pressure circumferential cuffs, frequently lead to tissue erosion, infection, and mechanical breakdown due to ischemic pressure. Addressing this core issue of biomechanical incompatibility is paramount. Novel mechanical designs, such as constant-force mechanisms, aim to mitigate pressure-induced injury. Furthermore, future optimization directions include enhancing device intelligence through smart sensing and AI algorithms, and exploring biohybrid designs that integrate tissue-engineered components to potentially achieve superior long-term integration. This review underscores that harmonizing mechanical function with the biological environment is critical for improving the safety, efficacy, and longevity of AASs in FI treatment.

Cartilage repair is a common problem in the clinic. Owing to the absence of vascular and lymphatic systems, cartilage exhibits a very limited capacity for self-repair, which complicates related research. The decellularized extracellular matrix (dECM), obtained by removing cellular components, preserves the natural structure and bioactive molecules of native ECM. This offers a biocompatible and bioactive environment for cell growth, making it a suitable and effective biomimetic scaffold material. In recent years, many studies have shown that the dECM has good effects on cartilage regeneration. However, there are no studies on the cartilage regeneration of decellularized matrix from different tissue sources, especially the related mechanisms. This article reviews the preparation methods for dECM and research on decellularized matrix derived from cartilage, fat, synovium, and dermis with respect to cartilage repair and regeneration, and further explores the application value and broad prospects of acellular ECM as a new tissue engineering biomimetic scaffold material. With further progress in dECM research and 3D bioprinting, their combination can better replicate native tissue architecture and function. This approach enables precise control of cells and materials, improves the regenerative niche, and may speed the clinical translation of biomimetic ECM for tissue repair.

Cobalt (Co) and chromium (Cr) are widely used in medical implants due to their strength and biocompatibility. However, implant wear and corrosion can lead to systemic release of these metals, raising concerns about cardiotoxic effects, especially with long-term exposure. This review summarizes current data on the potential cardiotoxicity of implant-derived Co and Cr, focusing on molecular mechanisms, inflammatory responses, and clinical observations. Case reports and clinical studies document considerable variability in serum Co and Cr concentrations postimplantation, influenced by implant type, material composition, and patient-specific factors. While extreme elevations are strongly associated with cardiomyopathy and fibrosis, moderate increases also correlate with subclinical changes such as ventricular dilatation and impaired strain. Nonetheless, many studies fail to find a direct relationship between ion levels and cardiac dysfunction, highlighting the complexity and interindividual variability of toxic responses and underlying pathomechanisms. Existing experimental data suggest that Co and Cr ions interfere with calcium and magnesium handling, impair mitochondrial respiration, and promote the generation of reactive oxygen species. Additionally, both metals can induce inflammatory responses, including cytokine release that results in DNA damage, apoptosis, and impaired cardiomyocyte physiology. Although Co and Cr implants offer substantial clinical benefits, emerging evidence indicates that they may contribute to cardiotoxicity in susceptible individuals. Current findings emphasize the importance of personalized monitoring, including serum ion concentration assessments and advanced imaging techniques. Given the absence of universally accepted toxicity thresholds, further mechanistic and longitudinal clinical studies are essential to define risk stratification strategies, establish safe exposure limits, and improve the cardiovascular safety of patients with metal implants.

The tendon-bone interface (TBI) possesses a highly intricate structure, making complete restoration of its native structure postinjury particularly challenging, which often leads to suboptimal healing outcomes. Metal ions, such as calcium (Ca²⁺), magnesium (Mg²⁺), zinc (Zn²⁺), copper (Cu²⁺), cobalt (Co²⁺), strontium (Sr²⁺), iron (Fe^2+/Fe³⁺), and lithium (Li⁺), have attached significant attention in tissue regeneration research owing to the excellent roles in promoting angiogenesis, osteogenesis, and chondrogenesis. This review systematically elucidates a comprehensive overview of the current understanding of these bioactive ions' mechanisms and their applications in TBI repair. Additionally, the review highlights the importance of incorporating metal ions into biomaterial scaffolds to enhance simultaneous multitissue regeneration while addressing current therapeutic limitations in TBI management. Finally, the review outlines future research directions for optimizing ion-based biomaterial strategies to advance TBI treatment paradigms. Impact Statement The tendon-bone interface (TBI) repair is challenging due to the structural complexity. While a lot of research has focused on restoring TBI functionally and structurally, there is no good strategy to achieve its complete repair. Metal ions play certain roles in promoting the repair of TBI. Therefore, this paper discussed the role of metal ions and materials applied to the TBI in the repair process and related mechanisms, aiming to provide reference for subsequent studies.