Biofabrication最新文献

Solid tumors reprogram their surrounding microenvironment to develop a tumor promoting and immunosuppressive niche of cells and extracellular matrix known as the tumor stroma. While many successful immunotherapies modulating the use of cytotoxic lymphocytes have been established, success in solid tumors has been limited, in part due to the stroma disrupting T cell infiltration and/or migration into the tumor boundary, thereby obstructing their contact with cancer cells. There exists a need for the development of three-dimensional (3D) tissue engineered models to better understand the mechanisms of infiltration and migration of solid tumors by cytotoxic lymphocytes. Here we present the validation of a 3D hydrogel system, implemented into a tumor-on-a-chip device, allowing for the observation of infiltration and migration of T cells, in addition to the influence that tumor cells have on stromal fibroblasts. This hydrogel allows for greater infiltration of T cells compared to other formulations. Differences in migration are observed depending on lymphocyte type. Fibroblasts are influenced towards a cancer-associated fibroblast morphology with increased alpha-smooth muscle actin expression, and are seen to modify their spatial orientation relative to A375 melanoma cells. Finally fibroblast presence in the hydrogel inhibits infiltration of T cells. Combined, these results validate the application of this model to study lymphocyte infiltration and migration into solid tumors. Future modulation of cell populations, along with the integration of patient derived samples, can provide a system to test immunotherapy effectiveness for cancer patients.

Microelectrode arrays (MEAs) can be used to record extracellular field potentials of cells, enabling investigations on neural or cardiac cellular electrical activity. However, conventionally used 2D cell monolayers cannot recapitulate the 3D microenvironment ofin vivotissue. Therefore, cells are grown in 3D cultures that mimic the architectural and functional aspects of human organs. MEAs that support such 3D structures are of increasing importance, but their fabrication often relies on advanced cleanroom techniques. Here, we present a fast and straightforward prototyping technique for a thin-film, porous MEA fabricated using conformal coatings and laser ablation. The absence of photolithography processes allows the MEA to be directly fabricated as a 3D structure. This advantage was exploited by manufacturing 3D, well-shaped MEAs to host cortical organoids for extracellular signal recordings. The 3D-printing-based fabrication of the wells enables the tuning of the MEA shape according to the size of the organoid. The proposed well-shaped MEAs enable easy handling and secure organoid placement by physically retaining the organoid within the well, ensuring direct alignment with underlying electrodes, avoiding the detachment issues typically encountered on 2D MEA designs. We present extracellular field potential recordings from both cardiac cells and cortical organoids.

Scaffold-free biofabrication has emerged as a promising strategy for cartilage repair, which may facilitate improved tissue integration while avoiding exogenous biomaterials. However, reproducible scaffold-free 3D bioprinting is strongly influenced by the robustness of the expanded cell population, particularly when induced pluripotent stem cell (iPSC)-derived neural crest mesenchymal stem cells (iNCMSCs) undergo repeated monolayer expansion. In this study, we tested whether TD-198946 priming during expansion could stabilize cell population quality and improve fabrication outcomes. TD-198946 priming supported iNCMSC expansion, as evidenced by increased cell number and MTT signal, accompanied by reduced G1 arrest and improved cell-cycle progression. These effects were reversed by the NOTCH3 signaling inhibitor DAPT, supporting the involvement of NOTCH3 as a mediator of TD-198946 activity. In parallel, TD-198946 priming increased N-cadherin expression in expanded iNCMSCs, a cell-cell adhesion molecule associated with spheroid cohesion in scaffold-free biofabrication systems. Applied to scaffold-free 3D bioprinting, TD-198946 priming led to dose-dependent increases in spheroid size, glycosaminoglycan deposition, and mechanical strength of the resulting constructs, with optimal construct quality observed at 50 nM. In contrast, excessive TD priming (100 nM) disrupted extracellular matrix production and resulted in inferior mechanical properties, highlighting the importance of dose optimization. This approach improved the robustness of the expanded iNCMSC population, thereby enhancing the consistency of scaffold-free biofabrication and construct maturation.

Current hemostatic materials often exhibit insufficient fluid absorption, poor mechanical stability, and limited tissue regenerative capacity. To overcome these limitations, this study proposed the concept of a capillary-driven hemostatic microenvironment. Through acid-enzymatic extraction of collagen from bovine hide (95.7% purity) and ion-exchange purification of carboxymethyl cellulose calcium (CMC-Ca) to enhance Ca²⁺content, oriented porous collagen/CMC-Ca composite scaffolds were fabricated using directional freeze-drying technology to construct aligned microchannels. The composite exhibited excellentin vitrohemocompatibility with hemolysis rates <3% and 40%-60% accelerated coagulation.In vivoevaluations using Sprague-Dawley rats tail amputation and liver hemorrhage models demonstrated that the optimal formulation (Col@2.5%CMC-Ca) achieved rapid hemostasis (tail: 120 ± 11 s, 0.49 ± 0.05 g blood loss; liver: 24.3 ± 8.7 s, 0.1 ± 0.08 g blood loss), reducing blood loss by 52%-86% compared to commercial controls. Furthermore, the scaffold promoted liver regeneration, showing significant tissue repair at 14 d post-implantation. This study establishes a dual-functional biomaterial integrating rapid hemostasis with proactive tissue repair, offering a promising solution to overcome existing limitations in hemostatic materials.

Bioprinting processes have greatly advanced in recent years through improvements in print accuracy and bioink optimization. Despite this progress, optimizing cell bioactivity still relies on guess-and-check processes with destructive testing post-printing. Measuring cell bioactivity during printing would improve print quality and inform complex printing processes, such as cell gradients or bioink transitions. Real-time monitoring using dielectric impedance spectroscopy alleviates this burden by correlating impedance |Z| to cell properties. However, the influence of bioink properties on these measurements is unknown. Using an in-line impedance sensor, we assessed the effect of alginate bioink concentration, pH, and crosslinking on impedance from 1 -25,000 kHz and determined how these properties influenced the detection of primary chondrocytes. Increasing the alginate concentration, decreasing the pH, or crosslinking with CaCl2 resulted in an increase in impedance. In nearly all samples, the addition of cells resulted in an increase in impedance compared to acellular samples, and this difference in impedance was used to quantify cell presence, termed |Zcells|. Higher alginate concentrations at 1 w/v% and 3 w/v% showed greater |Zcells|, indicating reliable cell detection. Although |Zcells| varied greatly with alginate or PBS pH, similar measurements were found in pH resembling cell media.Optimal frequency ranges for monitoring acellular and cellular samples were from 10 -100 kHz and 1,000 -25,000 kHz. Furthermore, cells were detected in real-time as acellular and cellular alginate bioinks were transitioned during bioprinting. This transition in cell concentration was spatially mapped to deposited bioink, providing a visual display of bioink transition using impedance. In summary, DIS was capable of detecting cells suspended in alginate bioink and showed potential for real-time mapping of cell deposition.

Bioink formulation plays a central role in determining the physical and biological performance of bioprinted tissue constructs. While compositional tuning has traditionally guided bioink development, a more mechanistic understanding of how material properties influence cellular behaviour remains underexplored. Here, we hypothesized that early-stage physicochemical properties, particularly rheological, printability, and swelling/degradation characteristics, can predict long-term biological outcomes. We systematically characterized the mechanical behaviour of fibrin-alginate-based bioink formulations and assessed their influence on neural progenitor cell viability, proliferation, and functional activity in three-dimensional culture. We compared regression models, multiple linear regression, lasso, ridge, elastic net, and support vector regression (SVR) using cross-validated RMSE andR². Performance was endpoint-dependent, but SVR provided the most consistent overall trade-off across outputs in this small, noisy dataset (best in 83% of features). External validation on chemically distinct bioinks revealed material-dependent transfer, robust for chitosan-and reduced for cellulose- and pluronic-based bioinks in selected readouts, thereby defining practical generalization limits. Finally, multi-objective optimization identified an optimal candidate (fibrin 20 mg ml^-1, alginate 1%), and experimental validation confirmed neuronal marker expression and extensive neurite outgrowth. Together, these results establish a rheology-informed, data-driven framework to prioritize bioink formulations, map cross-material predictability, and reduce empirical trial-and-error in neural biofabrication.

Porous membranes are frequently used as supports of cell monolayers in functional studies of epithelial and endothelial barriers. However, commonly used conventional polymer-based membranes such as those made of polycarbonate (transwells) do not mimic the structural and biochemical properties of native basement membranes, which may limit cellular differentiation and function. Here, we use a nanofibrillar membrane that mimics the microenvironment of the basement membrane and is made of recombinant spider silk functionalized with the integrin-binding RGD motif of fibronectin and coated with human kidney-specific laminin-521 (FN-silk). The FN-silk membranes were evaluated as culture substrates for renal epithelial cells (RPTEC/TERT1), a cell type notoriously difficult to differentiate in culture. FN-silk membrane structure, cellular morphology, mRNA expression, barrier properties and transporter activity were assessed using scanning and transmission electron microscopy, RNA-sequencing, permeability and transport assays. Both FN-silk and conventional membranes supported barrier integrity and tight junction expression. In contrast to cultures on conventional membranes, the RPTEC monolayers on FN-silk exhibited a differentiated morphology, low expression of cell death markers, and, directional anion and cation transport. Further, the commonly used conventional membranes released endocrine-disrupting bisphenols that activated estrogen-mediated signaling. In summary, these findings indicate that FN-silk membranes with kidney-specific basement membrane laminin 521 reduces cellular stress, supports and maintains cellular differentiation and preserves important cellular functions. Our work establishes FN-silk membranes as a next-generation biomaterial that enables the differentiation of renal epithelial monolayers into a physiologically relevantin vitromodel.

Three-dimensional (3D) bioprinting enables the fabrication of tissues with controlled architecture and cell composition, yet the formation of mature and functional vascular networks remains a major bottleneck for clinical translation. Constructs thicker than 100-200µm require stable and perfusable vasculature to sustain viability. This review compares vascularisation strategies in two contrasting contexts: regenerative tissue engineering, which requires hierarchical, mechanically stable networks capable of long-term perfusion and host integration, and tumour microenvironment modelling, which demands heterogeneous, leaky, and dynamically remodelling vasculature. Vascularisation approaches are examined across the complementary, technological and biological axes. The technological axis encompasses extrusion-, inkjet-, laser-, and microfluidic-assisted bioprinting methods, each with distinct trade-offs in resolution, cell viability, and scalability. Additionally, lumen-forming strategies, sacrificial, embedded, and coaxial printing, enable controlled formation of perfusable channels, while modular microgel-based bioinks enhance porosity, nutrient diffusion, and matrix remodelling. The biological axis comprises prevascularisation strategies and cellular mechanisms that drive functional vessel formation. Growth factor delivery (VEGF, FGF, PDGF) and hypoxia-driven angiogenesis provide biochemical stimuli, while co-culture systems combining endothelial cells with stromal partners (fibroblasts, pericytes, mesenchymal stem cells) promote endothelialisation, vessel stabilisation, and functional network formation. Mechanical and biochemical cues, including controlled flow, shear stress, and angiogenic factor gradients, are presented as key regulators of vascular maturation and perfusion stability. Validation metrics such as perfusion stability, oxygenation profiles, barrier integrity, and drug transport are emphasised as essential for assessing physiological relevance. Emerging technologies, including smart stimuli-responsive bioinks, 4D bioprinting enabling temporal tissue transformation, and AI-assisted adaptive volumetric fabrication, offer promising solutions for context-aware and dynamically regulated vascular systems. Together, this comparative framework guides strategy selection for either long-term regenerative perfusion or the pathophysiological complexity of tumour vascularisation, and provides practical design principles for translating vascularised tissue models toward clinical application and industrial-scale biofabrication.

Yanget alcomment on our article by Zahrabiet al(2025Biofabrication17045011 10.1088/1758-5090/adf803) titled '3D melt electrowritten MXene-reinforced scaffolds for tissue engineering applications' reporting the first demonstration of melt electrowritten (MEW) MXene/PCL scaffolds and their pro-osteogenic cellular response without exogenous growth factors. Here, we respond by clarifying MXene's role during MEW processing and its contribution to tissue scaffold properties by defining future research directions. Importantly, the MXene within the PCL scaffolds does not exhibit high electrical conductivity as pristine 2D MXene films do, since the investigated loadings are below the electrical percolation threshold. Therefore, bulk conductivity is not expected to dominate scaffold behavior. Instead, we attribute improved print resolution and stability to MXene-enabled interfacial and thermal effects that can stabilize the MEW jet and enhance filament definition. In addition, favorable interactions between MXene surface terminations and PCL strengthen interfacial adhesion and influence crystallization and degradation kinetics. We further discuss the surface functionalization strategies (e.g. APTES functionalization) that can improve MXene-polymer compatibility and may reduce oxidation susceptibility. Building on these points, we envision next steps including (i) investigation of osteoinductive signaling pathways mechanism, (ii) complementaryin vivoassessment in standard bone-defect models, (iii) fabrication of scalable structures by the development of hybrid manufacturing routes combining with MEW such as extrusion/hydrogel casting or electrospinning, and (iv) AI-guided optimization using existing material composition and process-structure models as a design constraint.