Biofabrication最新文献

Rapidin situbioprinting on complex, human-scale anatomical surfaces remains a key challenge for point-of-care use. Precise biomaterial ink or bioink deposition is required not only in operating theatres but also in resource-limited environments such as rural clinics and spaceflight missions. Here, we present a strategy for rapidly and conformally delivering biphasic biomaterial inks and bioinks composed of jammed gelatin microgels, optionally suspended in a cell-laden fibrinogen matrix. The formulation exhibits yield-stress behavior, preserves shape fidelity immediately after extrusion independent of gelation kinetics, maintains cell viability above 85%, and supports proliferation. The bioink is delivered through multinozzle printheads with 16 exit nozzles. During deposition at 450 mm²·s^-1, a ladder-rung channel architecture provided more uniform area coverage compared with a bifurcated design. Two printhead configurations were investigated: (1) a pneumatically actuated soft-robotic printhead with real-time adaptation to physiologically relevant convex surface curvatures, and (2) a rigid printhead integrated with a handheld bioprinter that enabled the first demonstration of biphasic jammed biomaterial ink deposition in microgravity. Considered radii of curvature and gravitational accelerations ranged from 10-100 mm and 0-1 g, respectively. Together with fibrin network formation, these results establish a translationally relevant biofabrication framework forin situbioprinting in regenerative medicine, austere trauma care, and space-based healthcare.

Bioprinting continues to redefine the frontiers of regenerative medicine by enabling the fabrication of complex, three-dimensional tissue constructs that emulate native biological and mechanical functions. However, despite significant progress, critical challenges remain, particularly in achieving precise multi-material integration, high-resolution patterning, and structural fidelity necessary for functional tissue engineering. A major limitation in "top-down" vat photopolymerization bioprinting, especially Digital Light Processing (DLP)-based approaches, lies in the precise control of layer thickness, a parameter that directly affects mechanical integrity, biological activity, and spatial resolution. This study presents a novel, automated platform designed to overcome one of the most persistent bottlenecks in multi-material top-down DLP bioprinting: the real-time, accurate measurement of the dynamic gap between the cured layer and the bioink surface. Through a comparative assessment of classical computer vision and deep learning (CNN-based) techniques, we demonstrate a system capable of achieving sub-0.1 mm precision (0.092 mm) with strong correlation to mechanical measurements (R = 0.994). This vision-based system adapts to a wide range of bioinks with varying viscosities, opacities, and photopolymerization kinetics, eliminating the need for manual recalibration during material switching. As a demonstration of its capabilities, we successfully printed a multimaterial vascular-like tissue structure with high spatial fidelity across heterogeneous biomaterials. Further, we bioprinted a multimaterial skin tissue model, featuring compartmentalized dermal/bone analogs, to enable in vitro functional evaluation. These case studies highlight the platform's potential to advance biofabrication workflows by improving reproducibility, material adaptability, and structural precision, paving the way toward clinically scalable tissue manufacturing systems. .

Tissue-engineered tendon constructs that replicate the structural and functional properties of natural tendons are crucial in regenerative medicine to improve treatment outcomes after tendon injury. This study aimed to engineer 3-dimensional biomimetic tendon macro-tissues through bioassembly of cell spheroids. Rat tendon fibroblasts seeded at different cell numbers (1×10⁴, 5×10⁴, 1×10⁵, 2×10⁵, 3×10⁵) were analysed for spheroid formation and development for 28 days. The spheroid diameters decreased over time with a reduction in cell density while synthesising their own collagen fibres. Spheroids were then bioassembled to form fused macro-tissue constructs using pillar array temporary supports. With the presence of ascorbic acid in growth media, the spheroids fused within 6 days after bioassembly, during which the supports were removed, leaving the constructs scaffold-free. The fused spheroids reorganised over time with increased fibrillar collagen content, showing elongated cell morphology in peripheral regions, which were parallelly aligned with collagen fibres resembling natural tendon micro-anatomy. The presence of scleraxis and tenomodulin gene markers also supports the tenogenic nature of tissue constructs. These biomimetic scaffold-free tenogenic macro-tissues have promising applications in tendon repair and regeneration, as in vitro models and tendon graft substitutes.

Engineered living materials (ELMs) are a class of hybrid materials that include engineered microbes encapsulated by a polymer matrix. The biotic and abiotic components define the ELMs design space and can be altered to improve performance and function. While current synthetic materials in the field display robust biocompatibility with both native and engineered living systems, we have a limited understanding of how to leverage 3D form factors to spatially organize and control microbial dynamics within the material. Motivated by this knowledge gap, we employed extrusion-based 3D printing to fabricate multi-material hydrogel constructs for the encapsulation of both single and dual-microbial systems. Core-shell cubic constructs enabled the spatial organization of a constitutive multi-kingdom system of levodopa (L-DOPA)-producing E. coli and betaxanthins-producing S. cerevisiae. This deliberate spatial organization in 3D materials can introduce precise control over bioproduction, bioprotection, and biocontainment, features that are critical to the efficacy of current ELMs. The relative spatial organization of the organisms, as well as the surface area-to-volume ratio were investigated to determine how these design elements impact microbial behavior (metabolite production, growth, expression and cell distribution) over time. We demonstrated that F127-BUM core-shell geometries enable the hierarchical 3D printing of multi-kingdom constructs, offering customizable control over bioproduction, bioprotection, and biocontainment. With the optimization of these core-shell structures for continuous bioproduction, these ELMs could be deployed as compact, sustainable bioreactors in remote environments.

Background: This study presents the development of a modular, growth-adaptive skull implant composed of calcium phosphate cement (CPC) intended for the reconstruction of large cranial defects in paediatric patients. The primary objective was to establish a systematic design and manufacturing workflow enabling patient-specific, resorbable implant solutions that accommodate dynamic skull growth while maintaining initial structural stability and supporting biological integration.

Methods: A six-phase methodology was implemented, including CT-based geometry acquisition, image segmentation, CAD-based implant modelling, and additive manufacturing using material extrusion. The implant design was subdivided into ten interlocking segments employing an S-shaped segmentation strategy and S-shaped cutting profiles to optimise inter-segment interaction, geometric stability, and guided mobility. A compact radial stabilisation and guidance structure was integrated to support geometrically critical regions while preserving overall porosity. Fixation was achieved using absorbable sutures in combination with form-fitting plug connections. The workflow was applied to a bilateral frontal cranial defect with an approximate area of 160 cm².

Results: The implant model was successfully designed and manufactured, demonstrating high geometric fidelity, effective modularity, and good manufacturability within the defined process chain. The segmentation strategy enabled controlled inter-segment mobility while maintaining overall implant coherence. No biomechanical simulations or biological evaluations were performed at this stage, as the focus was deliberately placed on validating the functional design and manufacturing process.

Conclusion: The presented approach demonstrates the technical feasibility of a modular, growth-adaptive CPC-based cranial implant and establishes a validated design and manufacturing framework. This work provides a fundamental basis for future biomechanical, biological, and clinical investigations aimed at advancing growth-adaptive implants for paediatric cranial reconstruction.

Skin injuries remain a significant challenge due to complex healing processes, which often results in delayed recovery, scarring, and impaired functionality. During the complicated wound repair, basic fibroblast growth factor (bFGF) serves as a core regulator for accelerating angiogenesis and fibroblast proliferation. However, conventional bFGF delivery systems suffer from rapid burst release and poor sustained bioavailability, severely limiting their therapeutic efficacy. Inspired by the interactions between the extracellular matrix (ECM) and growth factors in vivo, this study develops a polyanionic hydrogel system for the controlled delivery of bFGF to regulate healing processes. Considering the ionic properties of bFGF, negative 3-Sulfopropyl acrylate potassium salt (SPAK) was ultimately chosen as the affinity ligand, and SPAK could be covalently conjugated to Gelatin Methacryloyl (GelMA) network via photopolymerization. GelMA-SPAK hydrogel material exhibited well affinity-controlled release functionality, with sustained bFGF release maintained for at least 700 hours. Besides, bFGF-loaded hydrogel exhibits good cell compatibility, effectively promoted wound healing, improved tissue regeneration, and facilitated vascular growth without inducing significant inflammatory reactions, which may serve as a promising candidate for future intelligent wound dressing applications. .

Microvalve-based bioprinting (MBB) enables precise deposition of bioinks in the form of droplets through the controlled ejection of nanoliter-scale cylindrical ligaments. Despite its increasing use in tissue biofabrication, standardization criteria for assessing bioink printability remain limited. In this study, we present a quantitative printability toolbox for evaluating various bioinks, including fibrinogen, collagen type I, Matrigel, and alginate, in the context of MBB. We systematically analyzed how rheological properties and the contact angle influence ligament formation and droplet ejection. High-speed imaging captured ligament dynamics such as velocity and volume as well as droplet-substrate interactions. The role of Tween 20 (T20) surfactant was further investigated to reduce interfacial aggregation and improve droplet uniformity. Our results revealed viscosity and concentration thresholds specific to each bioink, enabling the construction of a comprehensive printability map correlating bioink properties with ligament stability and droplet printability. This framework provides a practical guide for bioink optimization in MBB towards reproducible fabrication of complex biological structures for biomedical applications.

Intrauterine adhesion (IUA) is a prevalent gynecological disorder characterized by endometrial fibrosis and compromised regeneration, with a lack of effective clinical treatments. Here, we present a microfluidic biofabrication strategy to engineer vascularized endometrial micro-organoids that recapitulate the cellular complexity and function of native tissue. By co-encapsulating human endometrial stromal cells, epithelial organoids, and endothelial cells (HUVECs) in biocompatible hydrogel microspheres, we created 3D constructs supporting hormone responsiveness, decidualization, and pathological remodeling upon transforming growth factor-βstimulation. Transcriptomic profiling and single-cell sequencing revealed that the presence of endothelial cells alleviated hypoxia-induced inflammation and promoted epithelial homeostasis.In vivotransplantation into a murine IUA model led to improved engraftment, endometrial regeneration, and fertility recovery. This vascularized organoid system offers a scalable and translational platform for endometrial repair and disease modeling, highlighting the promise of biofabrication in reproductive regenerative medicine.

The tumor microenvironment plays a critical role in drug resistance, with extracellular matrix (ECM) mechanics, cell-cell crosstalk, and transport barriers contributing to poor therapeutic outcomes. Traditional two-dimensional (2D) cultures fail to capture these features, and drug efficacy in 2D often does not translate to three-dimensional (3D) models or in vivo tumors. Here, we present a 3D tumor model integrated with a high-throughput biomechanical sensor array that enables simultaneous measurement of cellular forces and matrix remodeling. The platform, fabricated using a scalable and cost-effective micro-milling approach, supports the parallel generation of multiple tumor constructs within a single dish. To demonstrate feasibility, we formed in vitro tumors using patient-derived pancreatic ductal adenocarcinoma (PDAC) organoids, cancer cells, and stromal fibroblasts. The sensors were then applied to characterize the evolving biophysical properties of these tumors (tissue force and stiffness) and to evaluate responses to chemotherapy drug, gemcitabine, and the investigational agent, all-trans retinoic acid (ATRA). Drug responses in 3D tumors were compared with those in 2D cultures. By combining biochemical and biomechanical readouts, this 3D platform provides a more physiologically relevant tumor model and a powerful tool for preclinical drug testing and personalized medicine.

The drug development process in cancer faces significant challenges due to high failure rates in translational studies despite promisingin vitroresults. Additionally, conventional animal models exhibit inherent limitations and ethical concerns, constraining their relevance to cancer studies. Recognizing the pivotal role of the tumor microenvironment (TME) on cancer development and treatment outcomes, recent advancements in 3D microfluidic devices and tumor-on-a-chip models enabled researchers to explore the TME with enhanced accuracy and reliability, yielding novel insights. Notably, the emergence of physiological tumor models, particularly 3D models such as organoids derived from human tissues, provides a more accurate representation ofin vivotumor features. Moreover, 3D tumor models hold promise for diverse applications, including high-throughput drug testing, disease modeling, and regenerative medicine. Meanwhile, combining artificial intelligence (AI) with patient-derived tumor organoids has become a key strategy in predictive oncology and personalized cancer treatment. Furthermore, incorporating quantitative systems pharmacology and physiologically based pharmacokinetic modeling, and pharmacokinetics/pharmacodynamics analysis with generative AI (Gen-AI) has revolutionized predictive oncology by enabling precise simulations of drug interactions and patient-specific responses, thereby enhancing the predictive accuracy of personalized cancer treatments. These advanced methodologies harness the power of AI algorithms to analyze intricate datasets derived from patient-specific tumor organoids. Moreover, the predictive modeling capabilities of Gen-AI facilitate the development of personalized treatment strategies customized for each patient, thereby revolutionizing oncology practice. This review explores the synergistic impact of tumor-on-a-chip models, organoids derived from patient tumors, and Gen-AI. Together, these technologies mark a significant advancement in precision medicine, offering promising opportunities to improve therapeutic effectiveness and treatment outcomes in cancer care.