Journal of Tissue Engineering最新文献

Type 1 diabetes (T1D) results from the autoimmune destruction of pancreatic β cells, leading to lifelong insulin dependence and significant health complications. Human pluripotent stem cell-derived β cells (hPSC-β cells) have emerged as a promising therapeutic alternative for restoring endogenous insulin production; however, limitations such as functional immaturity, immune rejection, and biosafety concerns such as tumorigenic risk continue to hinder clinical application. Recent advances in gene editing technologies, particularly clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), offer precise tools to enhance or correct hPSC-β cell performance by improving glucose-stimulated insulin secretion (GSIS), reducing immune rejection, and reducing biosafety concerns. This review explores gene editing strategies developed to overcome the key barriers in hPSC-β cell-based therapy for T1D. We highlight how genetic modifications enhance or correct β cell function, promote immune evasion, and reduce biosafety concerns through precise and clinically relevant engineering. Finally, we discuss the current landscape of clinical trials and future directions for translating gene-edited hPSC-β cells into curative treatments for T1D.

Traumatic brain injury (TBI) is a major cause of mortality and morbidity, commonly leading to long-term impairments in cognition, sensorimotor function, and personality. While neuroprotective drugs have demonstrated some efficacy in vitro cultures and in vivo animal models, their clinical applications remain debated. Intranasal delivery to the brain parenchyma, bypassing the blood-brain barrier for more direct access to target sites, offers a favorable and safe approach. This review illuminates current advancements in intranasal delivery systems for TBI treatment. We begin with an overview of TBI and its current clinical treatment options. We then outline recent developments in intranasal delivery systems of molecules and cells, emphasizing their efficacy in animal models. Finally, we discuss future clinical perspectives on emerging trends, offering insights into leveraging intranasal delivery for effective TBI therapeutics.

Cardiac fibroblasts play an important role in heart homeostasis, regeneration, and disease by producing extracellular matrix (ECM) proteins and remodeling enzymes. Under normal conditions, fibroblasts exist in a quiescent state and maintain homeostasis, such as tissue structure and ECM turnover. However, if they become activated upon stimuli, such as injury, aging, or mechanical stress, which can lead to disease through excessive cell proliferation and ECM production. In addition to their role in disease progression, it remains unclear how cardiac fibroblasts contribute to cardiac maturation during development and whether the mechanism driving cytokine and ECM production during development aligns with those observed in pathological conditions. In this study, we investigated the functional and structural maturation of engineered cardiac tissue by modulating fibroblast activity within a three-dimensional (3D) in vitro model. In this model, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and human primary cardiac fibroblasts (FBs) were co-cultured in a fibrin gel and their morphology, beating characteristics, beating force, and mRNA expression profiles were analyzed. The results demonstrate that functional and structural maturation were enhanced by fibroblast-driven tissue contraction and collagen deposition, while inhibition of ECM remodeling impaired both processes. However, excessive collagen accumulation reduced functional maturation by limiting contractile efficiency. Our data suggest that ECM remodeling by cardiac fibroblasts is essential for cardiac tissue maintenance and maturation. Additionally, the regulation of collagen deposition by fibroblast activity will be a key focus of future research, as it may critically influence both cardiac development and the progression of heart disease.

The influence of neutrophils and of neutrophil extracellular traps (NETs) on post-traumatic tendon-to-bone healing was studied in a murine model. The impact of neutrophil infiltration on macrophage polarization and peritendinous fibrosis in early-stage Achilles tendon injury is reported. Mice underwent Achilles tendon-bone injury and divided into four groups: sham operation, tendon injury (TI) treated with acetylcellulose (vehicle control), TI treated with a Protein arginine deiminase-4 (PAD4) inhibitor GSK484, and TI treated with a neutrophil elastase inhibitor Sivelestat. Each group was monitored for 21 days. Post-traumatic neutrophil infiltration and NET formation were assessed using flow cytometry and immunofluorescence. Immunohistochemistry, Western blot, and qPCR were used to evaluate macrophage polarization. Peritendinous fibrosis was assessed using Masson staining and Western blot. Neutrophil infiltration and NET formation increased significantly in the tendon following injury. A significant increase in M1-related markers and a decrease in M2-related markers were associated with NET formation. NET Inhibition using GSK484 or sivelestat reduced M1 markers and increased M2 markers. Furthermore, NET inhibition during the early stage suppressed peritendinous fibrosis and reduced inflammation during the healing process. In co-culture experiments, NETs induced proinflammatory cytokine secretion and upregulated M1 markers in bone marrow-derived macrophages while downregulating M2 markers. nlsNETs promote early-phase tendon-bone injury by inducing M1 macrophage polarization and peritendinous fibrosis. Targeting NETs during the initial phase of tendon injury could potentially facilitate the healing process.

Dry eye disease is a complex ocular surface disorder with multifactorial pathophysiology, including corneal epithelial damage, chronic inflammation, and corneal nerve dysfunction. Among these, impaired corneal innervation plays a particularly critical role, as it disrupts neurotrophic support and tear reflexes, perpetuating disease progression, and delaying healing. However, conventional treatments often provide only temporary symptom relief without addressing underlying tissue damage or promoting nerve regeneration. This shortcoming highlights the need for therapies that not only suppress inflammation but also restore corneal innervation. In this study, we evaluated the therapeutic potential of mesenchymal stem cell (MSC) spheroid-derived secretome-a cell-free solution rich in regenerative and anti-inflammatory factors-in a preclinical mouse model of dry eye disease. Compared with untreated controls, eyes treated with the MSC spheroid secretome presented faster corneal epithelial regeneration, improved corneal nerve reinnervation, and reduced inflammatory cell infiltration. These findings demonstrate that the MSC spheroid-derived secretome can simultaneously target multiple pathological features of dry eye to promote recovery of ocular surface integrity, underscoring its potential as a clinically relevant, cell-free regenerative therapy for dry eye and other ocular surface disorders.

Lymphedema has emerged as a significant health issue among cancer survivors. The primary goal of treatment is to restore lymphatic drainage function. Engineering vascularized lymphatic tissue offers a promising alternative to achieve this goal. Currently, lymphatic tissue engineering with the use of cell-seeded scaffolds incubated in high hemodynamic flow environments, such as AV loop chambers, has shown promising results for lymphatic vessel regeneration. In this study, lymphatic endothelial cells (LECs) and adipose-derived stem cells (ASCs) were incorporated into an AV loop chamber and cultured in the groin region of a rat model. Surprisingly, the level of lymphangiogenesis, indicated by increased expression of the lymphatic marker LYVE-1, was significantly higher in the group with LECs alone than in the group with both LECs and ASCs. The engineered lymphatic tissue was subsequently orthotopically transplanted into the area of lymph node dissection. This procedure restored lymphatic drainage and reduced local inflammation, with decreased levels of CD3, CD4, and CD8 expression. These findings provide the potential for creating a functional, organized lymphatic system through the engineering of vascularized lymphatic tissue via AV loop cultivation, offering an applicable treatment option for lymphatic defects.

The development of small-diameter vascular grafts remains a major challenge in tissue engineering due to limited remodelling and regenerative capabilities. While strides have been made on the biofabrication of vessel mimics, little clinical translation success has been achieved to treat coronary artery disease (CAD). This study aimed to fabricate patient-specific bioengineered vessels using induced pluripotent stem cells (iPSCs) and functionalised biodegradable scaffolds. Human iPSCs were differentiated into mesenchymal stem cells (iMSCs) using SB431542, then further into vascular smooth muscle cells (VSMCs) with PDGF-BB and TGF-β1. Human bone marrow-derived MSCs (hBM-MSCs) were used to optimise differentiation protocols. Electrospun poly-L-lactide (PLLA) scaffolds coated with silk fibroin improved cell adhesion and proliferation. Both hBM-MSCs and iMSCs were seeded on these scaffolds for in-scaffold VSMC differentiation. The resulting cell-laden scaffolds were rolled into tubular structures (~3 mm inner diameter, ~20 mm length). Over 34-36 days, iPSCs differentiated into iMSCs expressing MSC markers (CD73, CD90, CD105), followed by successful VSMC differentiation within 9 days, confirmed by α-SMA, CNN1, SM22, and MYH-11 expression. Silk fibroin-coated PLLA scaffolds enhanced MSC adhesion and proliferation compared to uncoated scaffolds. The engineered tubular grafts displayed VSMC markers and mechanical properties akin to autologous coronary artery bypass grafts (CABGs). This study developed a versatile method to fabricate tissue-engineered blood vessels using stem cells and silk fibroin-coated scaffolds. The resulting grafts exhibited tunica media-like structures and mechanical properties comparable to autografts used in CABG, showing strong potential for clinical application.

The construction of bone organoids represents a transformative approach in tissue engineering, offering unprecedented opportunities for studying bone biology, disease modeling, and regenerative medicine. The intricate understanding of the skeletal microenvironment, or niche, which governs cellular behavior, tissue organization, and functional maturation, is critical important to construct bone organoid. This review explored insights into the skeletal microenvironment, including the roles of extracellular matrix components, mechanical cues, biochemical signaling, and cellular interactions. It also proposes a foundational strategy how advancements in biomaterials, extracellular matrix, and micro-structure have enabled the precise recapitulation of niche conditions, facilitating the development of physiologically relevant bone organoids. Furthermore, we highlight the applications of these organoids in drug screening, personalized medicine, and bone regeneration. By bridging the gap between niche biology and organoid engineering, this review underscores the potential of microenvironment-driven approaches to revolutionize bone tissue engineering and its translational impact.

Mesenchymal stem cell-mediated bone tissue engineering strategies, including human dental pulp stem cells (hDPSCs), represent an effective therapeutic approach for bone defect repair, particularly in maxillofacial bone defects. Growth differentiation factor 15 (GDF15), a multifunctional cytokine, plays a critical role in bone tissue formation and remodeling. This study aims to investigate the effects of GDF15 on the osteogenic differentiation of hDPSCs and elucidate the underlying molecular mechanisms. Our findings demonstrate that GDF15 expression and secretion are upregulated during the osteogenic differentiation of hDPSCs. Both Gdf15 overexpression and recombinant human GDF15 (rhGDF15) treatment significantly enhanced the osteogenic differentiation of hDPSCs, whereas Gdf15 knockdown produced the opposite effect. In vivo experiments demonstrated that hDPSCs treated with rhGDF15 significantly enhanced new bone formation within implants in both nude mouse subcutaneous transplantation and rat calvarial defect models. Proteomic analysis identified significant enrichment of the TGF-β/SMAD signaling pathway. Molecular docking analysis and co-immunoprecipitation demonstrated the direct binding interaction between GDF15 and TGF-βR2. Both in vitro Western blotting and in vivo immunofluorescence assays confirmed pathway activation. Critically, pharmacological inhibition of this pathway partially reversed the rhGDF15-induced enhancement of osteogenic differentiation in hDPSCs. Collectively, our findings demonstrate that GDF15 promotes osteogenic differentiation of hDPSCs through activation of the TGF-β/SMAD signaling pathway, thereby proposing a novel therapeutic strategy for bone repair and regenerative treatment.

Muscle spindles are key proprioceptive mechanoreceptors composed of intrafusal fibres that regulate kinaesthetic sensations and reflex actions. Traumatic injuries and neuromuscular diseases can severely impair the proprioceptive feedback, yet the regenerative potential and cell-matrix interactions of muscle spindles remain poorly understood. There is a pressing need for robust tissue-engineered models to study spindle development, function and regeneration. Traditional approaches, while insightful, often lack physiological relevance and scalability. Three-dimensional (3D) bioprinting offers a promising approach to fabricate biomimetic, scalable, and animal-free muscle spindle constructs with controlled cellular architecture. Various bioprinting techniques - including inkjet, extrusion, digital light projection and laser-assisted bioprinting - have been explored for skeletal muscle fabrication, but replicating intrafusal fibre complexity remains a challenge. A major challenge lies in bioink development, where biocompatibility, printability and mechanical strength must be balanced to support intrafusal fibre differentiation and proprioceptive function. Recent molecular insights into spindle anatomy, innervation and extracellular matrix composition are shaping biofabrication strategies. This review discusses the current state of muscle spindle modelling, the application of 3D bioprinting in intrafusal fibre engineering, key challenges and future directions.