Journal of Tissue Engineering最新文献

Spatial heterogeneity plays a key role in the development and function of human tissues and therefore needs to be incorporated within in vitro models to maximise physiological relevance and predictive power. Here, we developed and optimised methods to generate spatial heterogeneity of hydrogel-embedded bioactive signalling molecules within organ-on-a-chip (OOAC) systems, to drive spatiotemporal tissue patterning through controlled stem cell differentiation. As an exemplar application, we spatially patterned bone morphogenetic protein-2 (BMP-2) in both closed-channel and open-chamber OOAC formats. The resulting BMP-2 gradient in 3D heparin methacryloyl/gelatin methacryloyl, successfully drove spatially divergent differentiation of human bone marrow-derived stem cells into bone-like and cartilage-like regions, mimicking the process of endochondral ossification in the growth plate. The application of hydrogel-embedded morphogens to drive spatial tissue patterning within OOAC systems represents a significant technological advancement and has broad-ranging applicability for a diverse range of tissues and organs, and a wide variety of OOAC platforms.

Organoids, as 3D in vitro models derived from stem cells, have unparalleled advantages over traditional cell and animal models for studying organogenesis, disease mechanisms, drug screening, and personalized diagnosis and treatment. Despite the tremendous progress made in organoid technology, the translational application of organoids still presents enormous challenges due to the complex structure and function of human organs. In this review, the limitations of the translational application of traditional organoid technologies are first described. Next, we explore ways to address many of the limitations of traditional organoid cultures by engineering various dimensions of organoid systems. Finally, we discuss future directions in the field, including potential roles in drug screening, simulated microphysiology system and personalized diagnosis and treatment. We hope that this review inspires future research into organoids and microphysiology system.

By integrating 3D-inkjet bioprinting technology, differentiated human cells can be assembled into artificial lung tissue structure to achieve a rapid, efficient, and reproducible disease model construction process. Here, we developed a novel 3D-inkjet bioprinting-based method to construct artificial lung tissue structure (ALTs) for acute lung injury (ALI) disease modeling, research and application. It can also be used to study the role of relevant cells in the disease by adjusting the cell type and adapted to study the bio-functions of immune cells during the cell-cell interactions. Firstly, a series of process optimizations were done to mass-produce the alginate hydrogel microspheres (Alg) with a particle size of 262.63 ± 5 μm using a 3D bioprinter, then the type I collagen and polydopamine were deposited in turns to construct a cell adhesion layer on the surfaces of Alg (P-Alg) and the particle size was increased to 328.41 ± 3.81 μm. This platform exhibites good stability, timescale-dependent behavior, and long-term cell adhesion. Subsequently, several human cells including endothelial, epithelial, fibroblast, and even immune cells such as macrophages were adhered to P-Alg through rotational culture, leading to cell contractions and aggregation, subsequently formed ALTs or ALTs with macrophages (ALTs@M) with human alveolar-like structure. Finally, we successfully constructed an ALI model with lung barrier damage on ALTs using lipopolysaccharide stimulation in vitro, and comparison of secreted inflammatory factors between ALTs and ALTs@M. Results demonstrated that ALTs@M was more effective than ALTs in stimulating the inflammatory microenvironment of the lungs, providing a novel in vitro model for cellular interactions and human macrophage research. Altogether, this artificial lung tissue structure construction strategy using 3D-inkjet bioprinting technology allowed the flexible development of artificial lung tissue structures as potential disease models for preclinical studies.

Periodontal disease is a pervasive and serious health issue, affecting millions globally and leading to severe oral and systemic health complications. This underscores the urgent need to thoroughly understand the complex host-microbe interactions involved. Developing models that allow crosstalk among various bacteria, periodontal component cells, and circulating immune cells is crucial for investigating periodontal disease and discovering new treatments. This study aimed to develop a biomimetic gum tissue model. Within four days, a bio-fabricated tissue with well-established barrier and immune functions was created. In this model, the key periodontal pathogen, Porphyromonas gingivalis, was observed to suppress the recruitment and migration of immune cells and dysregulate CD14 expression in THP-1 cells, leading to significant inflammation and tissue damage. Conversely, the probiotic Akkermansia muciniphila enhanced the host's defensive immune response, highlighting its potential as a therapeutic agent in periodontal disease.

Chronic wounds represent an unresolved medical challenge with significant impact for patients' quality of life and global healthcare. Diverse in origin, ischemic-hypoxic and inflammatory conditions play central roles as pathological features that impede proper tissue regeneration. In this study, we propose an innovative approach to address this challenge. Our novel strategy utilizes photosynthetic biomaterials to restore the wound healing process firstly by promoting a normoxic, regeneration-supporting environment and secondly by mitigating inflammation through restoring lymphatic fluid transport and improving blood perfusion. We designed bioartificial scaffolds with photosynthetic cyanobacteria (Synechococcus sp. PCC 7002) and assessed their functional integration in a bilateral full-thickness skin defect on the backs of mice over a period of 7 days. Illuminated photosynthetic cyanobacteria facilitated local tissue oxygenation independent of blood perfusion. Additionally, genetic modification enabled the secretion of lymphangiogenic hyaluronic acid (HA) into the wound area. After 7 days, the scaffolds were explanted and histologically examined, assessing cell migration (HE staining) and protein expression (CD31, LYVE-1, VEGFR3, Ly6G, and F4/80). Results demonstrated successful colonization of bioartificial scaffolds with cyanobacteria. Following implantation into bilateral full-thickness skin defects, we observed an adherent vascularized basal layer beneath the bioactivated scaffolds after 7 days. Substantial increases in cell migration within bacteria-loaden scaffolds were noted, accompanied by a heightened expression of lymphatic (LYVE-1 and VEGFR3) and endothelial cell markers (CD31). Simultaneously, an augmented expression of acute (Ly6G) and late (F4/80) inflammatory proteins was observed. In summary, we developed a viable photosynthetic scaffold by integrating cyanobacteria into dermal regeneration materials (DRM), promoting the expression of lymphatic, endothelial, and inflammatory proteins under hypoxic conditions. The findings from this study represent a significant advancement in establishing autotrophic tissue engineering approaches, advocating for the use of photosynthetic cells in treating a broad spectrum of hypoxic conditions.

Peripheral neuropathies are disorders affecting the peripheral nervous system. Among them, Charcot-Marie-Tooth disease is an inherited sensorimotor neuropathy for which no effective treatment exists yet. Research on Charcot-Marie-Tooth disease has been hampered by difficulties in accessing relevant cells, such as sensory and motor neurons, Schwann cells, and myocytes, which interact at the neuromuscular junction, the specialized synapses formed between nerves and skeletal muscles. This review first outlines the various in vivo models and methods used to study neuromuscular junction deficiencies in Charcot-Marie-Tooth disease. We then explore novel in vitro techniques and models, including complex hiPSC-derived cultures, which offer promising isogenic and reproducible neuromuscular junction models. The adaptability of in vitro culture methods, including cell origin, cell-type combinations, and choice of culture format, adds complexity and excitement to this rapidly evolving field. This review aims to recapitulate available tools for studying Charcot-Marie-Tooth disease to understand its pathophysiological mechanisms and test potential therapies.

Endothelial injury is a key factor initiating in-stent restenosis (ISR) following peripheral artery stent implantation. Genetically modified endothelial progenitor cells (EPCs) can promote reendothelialization of injured arteries and inhibit neointimal hyperplasia. However, the role of engineered EPCs overexpressing lncRNA H19 in these processes remains unclear. We constructed EPCs overexpressing lncRNA H19 and investigated their effects and mechanisms in promoting reendothelialization and inhibiting neointimal hyperplasia both in vitro and in vivo. Compared to the normal control group, ISR patients exhibited a significant reduction in circulating EPCs. Engineered EPCs overexpressing lncRNA H19 promoted reendothelialization and inhibited neointimal hyperplasia in injured arteries. Exogenous overexpression of lncRNA H19 significantly upregulated the endothelial repair-related gene S1PR3 in EPCs, while the opposite was also observed. Additionally, engineered EPCs overexpressing S1PR3 promoted reendothelialization and inhibited neointimal hyperplasia in injured arteries. S1PR3 overexpression enhanced EPCs proliferation, migration, and tube formation in vitro; these effects were lost with S1PR3 inhibition. Binding sites for H3K27 acetylation were identified on the S1PR3 promoter. Mechanistically, we found that lncRNA H19 directly interacted with HDAC2, a known H3K27ac deacetylase, disrupting its binding to H3K27 acetylation. Our findings suggest that lncRNA H19 positively regulates S1PR3 expression by disrupting HDAC2 / H3K27ac binding, thereby promoting reendothelialization of injured arteries and inhibiting neointimal hyperplasia.

The benefit of complex 3D models to facilitate the robust testing of new drugs and drug delivery systems during the developmental stages of pharmaceutical manufacturing has recently become distinguished within the field. Recognition of this need by the pharmaceutical industry has provided a motivation for research into the development of reliable complex models for use in drug delivery, biomaterials, and tissue engineering. Both 3D in vitro and ex vivo models can enhance drug-testing and discovery prospects over the more traditionally used 2D, monolayer culture systems and animal models. Despite the widespread acceptance that 3D tissue modelling is advantageous in this field, there remains a lack of standardisation in the models throughout literature. This article provides an extensive review of current literature on in vitro, and ex vivo models of the oral mucosa for drug delivery applications; the advantages, limitations, and recommendations for future development of improved models for this application.

Osteoarthritis (OA) is an age-related chronic inflammatory disease, predominantly characterized by chondrocyte senescence and extracellular matrix (ECM) degradation. Although mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) are promising for promoting cartilage regeneration, their clinical application is limited by inconsistent therapeutic effects and insufficient targeting capabilities. Mechanical loading shows potential to optimize MSC-EVs for OA treatment, while the underlying mechanism is not clear. In this study, EVs derived from mechanical loading-primed MSCs (ML-EVs) demonstrate prominent efficacy in maintaining ECM homeostasis and relieving chondrocyte senescence, thereby mitigating OA. Subsequent miRNA sequencing reveals that ML-EVs exert their effects by delivering miR-27b-3p, which targets ROR1 mRNA in chondrocytes and suppresses downstream NF-κB pathways. By modulating the ROR1/NF-κB axis, miR-27b-3p effectively restrains ECM degradation and chondrocyte senescence. To optimize therapeutic efficacy of EVs, miR-27b-3p is overexpressed within EVs (miR^OE-EVs), and a chondrocyte-targeted peptide (CTP) is conjugated to their surface, thereby constructing dual-engineered chondrocyte-targeted EVs (CTP/miR^OE-EVs). CTP/miR^OE-EVs exhibit excellent ability to specifically target cartilage and ameliorate OA pathology. In conclusion, this study underscores the critical role of mechanical loading in augmenting effectiveness of EVs in mitigating OA and introduces dual-engineered EVs that specifically target chondrocytes, providing a promising therapeutic strategy for OA.

Atopic dermatitis (AD) is a chronic relapsing dermatosis that demands new therapies. This research group previously developed a physically extracted adipose-derived extracellular matrix named adipose collagen fragments (ACF), which was determined containing massive adipose matrix-bound adipokines and medicable on AD through intradermal injection. However, problems concerning the control of drug release and inevitable pain caused by injection hinder the application of ACF in clinics. Microneedle (MN) is a rapid developing technique for precise and painless transdermal drug delivery. Therefore, a dissolving methacrylated gelatin/hyaluronic acid MN patch loaded with ACF was developed in this study. The morphological characteristics, mechanical properties, penetration ability, as well as biocompatibility and degradation efficiency of ACF-MN were evaluated, and its efficacy on ovalbumin-induced AD mice was also investigated. ACF-MN exhibited excellent penetration ability, biocompatibility, degradation efficiency, and satisfying efficacy on murine AD similar with fresh-made ACF. Furthermore, RNA-Seq combining bioinformatics were performed for mechanism exploration. ACF treatment showed a comprehensive efficacy on AD via restoring inflammatory dysregulation, microbiota imbalance, and skin barrier defects. This study offered a novel MN-based ACF-bound adipokines transdermal delivery system that may serve as a promising strategy for relieving AD.