Biofabrication最新文献

In contrast to traditional two-dimensional cell-culture conditions, three-dimensional (3D) cell-culture models closely mimic complexin vivoconditions. However, constructing 3D cell culture models still faces challenges. In this paper, by using micro/nano fabrication method, including lithography, deposition, etching, and lift-off, we designed magnetic nanostructures resembling a crown of thorns. This magnetic crown of thorns (MCT) nanostructure enables the isolation of cells that have endocytosed magnetic particles. To assess the utility of this nanostructure, we used high-flux acquisition of Jurkat cells, an acute-leukemia cell line exhibiting the native phenotype, as an example. The novel structure enabled Jurkat cells to form spheroids within just 30 min by leveraging mild magnetic forces to bring together endocytosed magnetic particles. The size, volume, and arrangement of these spheroids were precisely regulated by the dimensions of the MCT nanostructure and the array configuration. The resulting magnetic cell clusters were uniform in size and reached saturation after 1400 s. Notably, these cell clusters could be easily separated from the MCT nanostructure through enzymatic digestion while maintaining their integrity. These clusters displayed a strong proliferation rate and survival capabilities, lasting for an impressive 96 h. Compared with existing 3D cell-culture models, the approach presented in this study offers the advantage of rapid formation of uniform spheroids that can mimicin vivomicroenvironments. These findings underscore the high potential of the MCT in cell-culture models and magnetic tissue enginerring.

The field of bone tissue engineering aims to develop an effective and aesthetical bone graft substitute capable of repairing large mandibular defects. However, graft failure resulting from necrosis and insufficient integration with native tissue due to lack of oxygen and nutrient transportation remains a concern. To overcome these drawbacks, this study aims to develop a 3D printed polycaprolactone layered construct with a LEGO^®-inspired interlocking mechanism enabling spatial distribution of biological components. To highlight itsin vitroosteogenic potential, human mesenchymal stromal cells are cultured onto Bio-Gide^®Compressed collagen (Col) membranes, which are embedded within the layered construct for 28 d. The osteogenic response is assessed through the measurement of proliferation, relevant markers for osteogenesis including alkaline phosphatase (ALP) activity, expression of transcriptional genes (SP7, RUNX2/SOX9) as well matrix-related genes (COL1A1, ALPL IBSP, SPP1), osteoprotegerin secretion.In vitroosteogenic differentiation results showed increased levels of these osteogenic markers, indicating the layered construct's potential to support osteogenesis. In this study, a novel workflow of 3D printing a patient-specific LEGO^®-inspired layered construct that can spatially deliver biological elements was successfully demonstrated. These layered constructs have the potential to be employed as a bone tissue engineering strategy, with particular focus on the repair of large mandibular defects.

Reconstructing the microscale villous organisation and functionality of the small intestine is essential for developingin vitroplatforms tailored for absorption studies as well as for investigating intestinal morphogenesis in development and disease. However, the current fabrication techniques able to mimic the villus-crypt axis poses significant challenges in terms of reconstruction of the complex 3D microarchitecture. These challenges extend beyond mere structural intricacies to encompass the incorporation of diverse cell types and the management of intricate fluid dynamics within the system. Here, we introduce a novel microfluidic device calledIn-Crypts, which integrates a cell-instructive membrane aimed at inducing and guiding Caco-2 cells morphogenesis. Patterned topographical cues embossed onto the porous membrane induce the formation of a well-organized intestinal epithelium, characterized by proliferating crypt-like domains and differentiated villus-like regions. Notably, our cell-instructive porous membrane effectively sustains stem cells development, faithfully replicating the niche environment ofin vivointestinal crypts thus mirroring the cell biogeography observedin vivo. Moreover, by introducing dynamic fluid flow, we provide a faithful recapitulation of the native microenvironmental shear stress experienced by the intestinal epithelium. This stress plays a crucial role in influencing cell behaviour, differentiation, and overall functionality, thus offering a highly realistic model for studying intestinal physiology and pathology. The resulting intestinal epithelium exhibits significantly denser regions of mucus and microvilli, characteristic typically absent in static cultures, upregulating more than 1.5 of the amount expressed in the classical flattened configuration, enhanced epithelial cell differentiation and increased adsorptive surface area. Hence, the innovative design ofIn-Cryptsproves the critical role of employing a cell-instructive membrane in argument the physiological relevance of organs-on-chips. This aspect, among others, will contribute to a more comprehensive understanding of organism function, directly impacting drug discovery and development.

This study proposed an optimized histogel construction method for histological analysis by applying lung cancer patient-derived organoids (PDOs) to the developed histo-pillar strip. Previously, there is the cultured PDOs damage problem during the histogel construction due to forced detachment of the Matrigel spots from the 96-well plate bottom. To address this issue, we cultured PDO on the proposed Histo-pillar strips and then immersed them in 4% paraformaldehyde fixation solution to self-isolate PDO without damage. The 4μl patient-derived cell (PDC)/Matrigel mixtures were dispensed on the surface of a U-shaped histo-pillar strip, and the PDCs were aggregated by gravity and cultured into PDOs. Cultured PDOs were self-detached by simply immersing them in a paraformaldehyde fixing solution without physical processing, showing about two times higher cell recovery rate than conventional method. In addition, we proposed a method for embedding PDOs under conditions where the histogel temperature was maintained such that the histogel did not harden, thereby improving the problem of damaging the histogel block in the conventional sandwich histogel construction method. We performed histological and genotyping analyses using tumor tissues and PDOs from two patients with lung adenocarcinoma. Therefore, the PDO culture and improved histogel block construction method using the histo-pillar strip proposed in this study can be employed as useful tools for the histological analysis of a limited number of PDCs.

One ever-evolving and ever-demanding critical human endeavour is the provision of food security for the growing world population. This can be done by adopting sustainable agriculture through horizontal (expanding the arable land area) and vertical (intensifying agriculture through sound technological approaches) interventions. Customized formulated nanomaterials have numerous advantages. With their specialized physico-chemical properties, some nanoparticulated materials improve the plant's natural development and stress tolerance and some others are good nanocarriers. Nanocarriers in agriculture often coat chemicals to form composites having utilities with crop productivity enhancement abilities, environmental management (such as ecotoxicity reduction ability) and biomedicines (such as the ability to control and target the release of useful nanoscale drugs). Ag, Fe, Zn, TiO₂, ZnO, SiO₂and MgO nanoparticles (NPs), often employed in advanced agriculture, are covered here. Some NPs used for various extended purposes in modern farming practices, including disease diagnostics and seed treatment are also covered. Thus, nanotechnology has revolutionized agrotechnology, which holds promise to transform agricultural (ecosystems as a whole to ensure food security in the future. Considering the available literature, this article further probes the emergent regulatory issues governing the synthesis and use of nanomaterials in the agriculture sector. If applied responsibly, nanomaterials could help improve soil health. This article provides an overview of the nanomaterials used in the distribution of biomolecules, to aid in devising a safer and eco-friendly sustainable agriculture strategy. Through this, agri-systems that depend on advanced farming practices might function more effectively and enhance agri-productivity to meet the food demand of the rising world population.

Three-dimensional cell spheroids show promise for the reconstruction of native tissues. Herein, we report a sophisticated, uniform, and highly reproducible spheroid culture system for tissue reconstruction. A mesh-integrated culture system was designed to precisely control the uniformity and reproducibility of spheroid formation. Furthermore, we synthesized hexanoyl glycol chitosan, a material with ultralow cell adhesion properties, to further improve spheroid formation efficiency and biological function. Our results demonstrate improved biological function in various types of cells and ability to generate spheroids with complex structures composed of multiple cell types. In conclusion, our spheroid culture system offers a highly effective and widely applicable approach to generating customized spheroids with desired structural and biological features for a variety of biomedical applications.

Three-dimensional (3D) printing is an emerging tool for creating patient-specific tissue constructs analogous to the native tissue microarchitecture. In this study, anatomically equivalent 3D nerve conduits were developed using thermoplastic polyurethane (TPU) by combining reverse engineering and material extrusion (i.e. fused deposition modeling) technique. Printing parameters were optimized to fabricate nerve-equivalent TPU constructs. The TPU constructs printed with different infill densities supported the adhesion, proliferation, and gene expression of neuronal cells. Subcutaneous implantation of the TPU constructs for three months in rats showed neovascularization with negligible local tissue inflammatory reactions and was classified as a non-irritant biomaterial as per ISO 10993-6. To performin vivoefficacy studies, nerve conduits equivalent to rat's sciatic nerve were fabricated and bridged in a 10 mm sciatic nerve transection model. After four months of implantation, the sensorimotor function and histological assessments revealed that the 3D printed TPU conduits promoted the regeneration in critical-sized peripheral nerve defects equivalent to autografts. This study proved that TPU-based 3D printed nerve guidance conduits can be created to replicate the complicated features of natural nerves that can promote the regeneration of peripheral nerve defects and also show the potential to be extended to several other tissues for regenerative medicine applications.

3D (Bio)printing is a highly effective method for fabricating tissue engineering scaffolds, renowned for their exceptional precision and control. Artificial intelligence (AI) has become a crucial technology in this field, capable of learning and replicating complex patterns that surpass human capabilities. However, the integration of AI in tissue engineering is often hampered by the lack of comprehensive and reliable data. This study addresses these challenges by providing one of the most extensive datasets on 3D-printed scaffolds. It provides the most comprehensive open-source dataset and employs various AI techniques, from unsupervised to supervised learning. This dataset includes detailed information on 1171 scaffolds, featuring a variety of biomaterials and concentrations-including 60 biomaterials such as natural and synthesized biomaterials, crosslinkers, enzymes, etc.-along with 49 cell lines, cell densities, and different printing conditions. We used over 40 machine learning and deep learning algorithms, tuning their hyperparameters to reveal hidden patterns and predict cell response, printability, and scaffold quality. The clustering analysis using KMeans identified five distinct ones. In classification tasks, algorithms such as XGBoost, Gradient Boosting, Extra Trees Classifier, Random Forest Classifier, and LightGBM demonstrated superior performance, achieving higher accuracy and F1 scores. A fully connected neural network with six hidden layers from scratch was developed, precisely tuning its hyperparameters for accurate predictions. The developed dataset and the associated code are publicly available onhttps://github.com/saeedrafieyan/MLATEto promote future research.

Three-dimensional (3D) cell culture models capable of emulating the biological functions of natural tissues are pivotal in tissue engineering and regenerative medicine. Despite progress, the fabrication ofin vitroheterocellular models that mimic the intricate structures of natural tissues remains a significant challenge. In this study, we introduce a novel, scaffold-free approach leveraging the inertial focusing effect in rotating hanging droplets for the reliable production of heterocellular spheroids with controllable core-shell structures. Our method offers precise control over the core-shell spheroid's size and geometry by adjusting the cell suspension density and droplet morphology. We successfully applied this technique to create hair follicle organoids, integrating dermal papilla cells within the core and epidermal cells in the shell, thereby achieving markedly enhanced hair inducibility compared to mixed-structure models. Furthermore, we have developed melanoma tumor spheroids that accurately mimic the dynamic interactions between tumor and stromal cells, showing increased invasion capabilities and altered expressions of cellular adhesion molecules and proteolytic enzymes. These findings underscore the critical role of cellular spatial organization in replicating tissue functionalityin vitro. Our method represents a significant advancement towards generating heterocellular spheroids with well-defined architectures, offering broad implications for biological research and applications in tissue engineering.

Various anisotropic tissue structures exist in organisms, including muscle tissue, skin tissue, and nerve tissue. Replicating anisotropic tissue structuresin vitrohas posed a significant challenge. Three-dimensional (3D) printing technology is often used to fabricate biomimetic structures due to its advantages in manufacturing principle. However, direct 3D printing of freeform anisotropic bioactive structures has not been reported. To tackle this challenge, we developed a ternary F/G/P ink system that integrates the printability of Pluronic F127 (F), the robust bioactivity and photocrosslinking properties of gelatin methacryloyl (G), and the shear-induced alignment functionality of high-molecular-weight polyethylene glycol (P). And through this strategic ternary system combination, freeform anisotropic tissue structures can be 3D printed directly. Moreover, these anisotropic structures exhibit excellent bioactivity, and promote orientational growth of different cells. This advancement holds promise for the repair and replacement of anisotropic tissues within the human body.