Biofabrication最新文献

Three-dimensional (3D) printing incorporated with controlled delivery is an effective tool for complex tissue regeneration. Here, we explored a new strategy for spatiotemporal delivery of bioactive cues by establishing a precise-controlled micro-thin coating of hydrogel carriers on 3D-printed scaffolds. We optimized the printing parameters for three hydrogel carriers, fibrin cross-linked with genipin, methacrylate hyaluronic acid, and multidomain peptides, resulting in homogenous micro-coating on desired locations in 3D printed polycaprolactone microfibers at each layer. Using the optimized multi-head printing technique, we successfully established spatial-controlled micro-thin coating of hydrogel layers containing profibrogenic small molecules (SMs), Oxotremorine M and PPBP maleate, and a chondrogenic cue, Kartogenin. The delivered SMs showed sustained releases up to 28 d and guided regional differentiation of mesenchymal stem cells, thus leading to fibrous and cartilaginous tissue matrix formation at designated scaffold regionsin vitroandin vivo. Our micro-coating of hydrogel carriers may serve as an efficient approach to achieve spatiotemporal delivery of various bioactive cues through 3D printed scaffolds for engineering complex tissues.

This study introduces a novelin vitromodel for intractable temporal lobe epilepsy (TLE) utilizing 3D bioprinting technology, aiming to replicate the complex neurobiological characteristics of TLE more accurately. Primary neural cell constructs were fabricated and subjected to epileptiform-inducing conditions, fostering synaptic proliferation and neuronal loss. Systematically electrophysiological and immunofluorescent analyses indicated that significant synaptic connectivity and sustained epileptiform activities within the constructs akin to those observed in human epilepsy models. Notably, the model responded to treatments with phenytoin and tetrodotoxin, illustrating its potential utility in drug response kinetics studies. Furthermore, we performed drug permeability simulations using COMSOL Multiphysics to analyze the diffusion characteristics of these drugs within the constructs. These results confirm that our 3D bioprinted neural model provides a physiologically relevant and ethically sustainable platform, which is beneficial for studying TLE mechanisms and developing therapeutic strategies with high accuracy and clinical relevance.

Artificial bone graft stands out for avoiding limited source of autograft as well as susceptibility to infection of allograft, which makes it the current research hotspot in the field of bone defect repair. However, traditional design and manufacturing method cannot fabricate bone scaffold that well mimics complicate bone-like shape with interconnected porous structure and multiple properties akin to human natural bone. Additive manufacturing, which can achieve implant's tailored external contour and controllable fabrication of internal microporous structure, is able to form almost any shape of designed bone scaffold via the layer-by-layer process. As additive manufacturing is promising in building artificial bone scaffold, only combining excellent structural design with appropriate additive manufacturing process can produce bone scaffold with ideal biological and mechanical properties. In this article, we sum up and analyze state of art design and additive manufacturing methods for bone scaffold to realize shape/properties collaboratuve intelligent manufacturing. Scaffold design can be mainly classified to design based on unit cells and whole structure, while the basic additive manufacturing and 3D bioprinting are the recommended suitable additive manufacturing methods for bone scaffold fabrication. The challenges and future perspectives in additive manufactured bone scaffold are also discussed. .

Three-dimensional (3D) organotypic skin in vitro has attracted increasing attention for drug development, cosmetics evaluation, and even clinical applications. However, the severe contraction of these models restricts their application, especially in the analyses based on barrier functions such as percutaneous penetration. For the full-thickness skin equivalents, the mechanical properties of the dermis scaffold plays an important role in the contraction resistance. In this investigation, we optimized a hydrogel composed of gelatine methacrylamide (GelMA), hyaluronic acid methacrylate (HAMA), and type I collagen (Col I), adjusted the elastic moduli to 2.27±0.08 kPa to fit the skin cells growth and resist contraction as well. This optimized hydrogel exhibited a swelling ratio of 23.25 ± 0.94% and demonstrated satisfactory cell viability in fibroblasts cultures. Then, we mixed this hydrogel with fibroblasts of liquid-liquid culture to construct the dermis, on which seeded keratinocytes were seeded for another 14 days of air-liquid culture to form cornified epidermis, and a commercialized hydrogel Ava-FT-Skin was used as control. This optimized skin model could maintained its integrity for a prolonged period of 28 days. Differentiated epidermis presented basal, spinous, granular, and cornified layers, meanwhile, epidermis markers like keratin-10, keratin-14, involucrin, loricrin, filaggrin, and dermis markers vimentin were expressed distinctly in the right distribution. Furthermore, penetration of a 607 Da Cascade blue-labelled dextran was calculated and compared to the Avatarget skin model, both of which could prevent more than 99% of the fluorescent molecule. We consider that this full-thickness skin model could be widely used in pharmaceutical and cosmetic industries, especially in penetration detection, contributing to the excellent contraction resistance.

Emergency wounds are often accompanied by bacterial infection, oxidative stress, and excessive inflammation due to the inability to quickly close and stop bleeding, resulting in chronic wounds that are difficult to heal. Clinically, surgical suturing is the fastest method for wound closure, but it is only suitable for wounds with small bleeding volumes and causes unsightly scar formation. Consequently, there is a critical need for hemostatic dressings versatile enough to address a spectrum of diverse and intricate wounds, especially in emergency scenarios. In this study, we constructed a unique versatile natural gelatin-based hydrogel with hemostasis, antibacterial, and anti-inflammation properties. The hydrogel was composed of 4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy) butyrylethylenediamine-modified methacrylated gelatin (GelMA-NB) and epigallocatechin gallate-grafted polylysine (EPL-EGCG), which imparts adhesion, antibacterial and antioxidant properties to the hydrogel. Simultaneously, the hydrogel was loaded with GelMA microspheres encapsulating natural resveratrol (RES@GM). This combination not only exhibited outstanding hemostatic capabilities but also preserved the anti-inflammatory potential of RES. In different animal models, the hydrogel exhibited outstanding hemostatic and wound healing effects, down-regulated the expression of IL-1βto promote inflammatory regulation and potential for angiogenesis and anti-scar. In conclusion, unique versatile natural gelatin-based hydrogel suitable for various complex wounds provides a promising strategy for emergency wound dressing applications.

This study investigates osteoblastic cell spheroid cultivation methods, exploring flat-bottom, U-bottom, and rotary flask techniques with and without amorphous calcium phosphate (ACP) supplementation to replicate the 3D bone tissue microenvironment. ACP particles derived from eggshell waste exhibit enhanced osteogenic activity in 3D models. However, representative imaging of intricate 3D tissue-engineered constructs poses challenges in conventional imaging techniques due to notable scattering and absorption effects in light microscopy, and hence limited penetration depth. We investigated contrast-enhanced micro-CT as a methodological approach for comprehensive morphological 3D-analysis of thein-vitromodel and compared the technique with confocal laser scanning microscopy, scanning electron microscopy and classical histology. Phosphotungstic acid and iodine-based contrast agents were employed for micro-CT imaging in laboratory and synchrotron micro-CT imaging. Results revealed spheroid shape variations and structural integrity influenced by cultivation methods and ACP particles. The study underscores the advantage of 3D spheroid models over traditional 2D cultures in mimicking bone tissue architecture and cellular interactions, emphasising the growing demand for novel imaging techniques to visualise 3D tissue-engineered models. Contrast-enhanced micro-CT emerges as a promising non-invasive imaging method for tissue-engineered constructs containing ACP particles, offering insights into sample morphology, enabling virtual histology before further analysis.

Cartilage tissue engineering (CTE) with the help of engineered constructs has shown promise for the regeneration of hyaline cartilage, where fibrocartilage may also be formed due to the biomechanical loading resulting from the host weight and movement. Previous studies have primarily reported on hyaline cartilage formationin vitroand/or in small animals, while leaving the fibrocartilage formation undiscovered. In this paper, we, at the first time, present a comparison study on hyaline cartilage versus fibrocartilage formation in a large animal model of pig by using two constructs (namely hydrogel and hybrid ones) engineered by means of three-dimensional (3D) bioprinting. Both hydrogel and hybrid constructs were printed from the bioink of alginate (2.5%) and ATDC5 cells (chondrogenic cells at a cell density of 5 × 10⁶cells ml^-1), with the difference in that in the hybrid construct, there was a polycaprolactone (PCL) strand printed between every two bioink strands, which were strategically designed to shield the force imposed on the cells within the bioink strands. Both hydrogel and hybrid constructs were implanted into the chondral defects created in the articular cartilage of weight-bearing portions of pig stifle joints; the cartilage formation was examined at one- and three-months post-implantation, respectively, by means of Safranin O, Trichrome, immunofluorescent staining, and synchrotron radiation-based (SR) inline phase contrast imaging microcomputed tomography (inline-PCI-CT). Glycosaminoglycan (GAG) and collagen type II (Col II) secretion were used to evaluate the hyaline cartilage formation, while collagen type I (Col I) was used to indicate fibrocartilage given that Col I is low in hyaline cartilage but high in fibrocartilage. Our results revealed that cartilage formation was enhanced over time in both hydrogel and hybrid constructs; particularly, the hydrogel construct exhibited more cartilage formation at both one- and three-months post-implantation, while hybrid constructs tended to have less fibrocartilage formed in a long time period. Also, the result from the inline-PCI-CT revealed that the inline-PCI-CT was able to provide not only the information seen in other histology images, but also high-resolution details of biomaterials and regenerating cartilage. This would represent a significant advance toward the non-invasive assessment of cartilage formation regeneration within large animal models and eventually in human patients.

Physiologically relevant human skin models that include key skin cell types can be used forin vitrodrug testing, skin pathology studies, or clinical applications such as skin grafts. However, there is still no golden standard for such a model. We investigated the potential of a recombinant functionalized spider silk protein, FN-silk, for the construction of a dermal, an epidermal, and a bilayered skin equivalent (BSE). Specifically, two formats of FN-silk (i.e. 3D network and nanomembrane) were evaluated. The 3D network was used as an elastic ECM-like support for the dermis, and the thin, permeable nanomembrane was used as a basement membrane to support the epidermal epithelium. Immunofluorescence microscopy and spatially resolved transcriptomics analysis demonstrated the secretion of key ECM components and the formation of microvascular-like structures. Furthermore, the epidermal layer exhibited clear stratification and the formation of a cornified layer, resulting in a tight physiologic epithelial barrier. Our findings indicate that the presented FN-silk-based skin models can be proposed as physiologically relevant standalone epidermal or dermal models, as well as a combined BSE.

Biofabrication is an advanced technology that holds great promise for constructing highly biomimeticin vitrothree-dimensional human organs. Such technology would help address the issues of immune rejection and organ donor shortage in organ transplantation, aiding doctors in formulating personalized treatments for clinical patients and replacing animal experiments. Biofabrication typically involves the interdisciplinary application of biology, materials science, mechanical engineering, and medicine to generate large amounts of data and correlations that require processing and analysis. Artificial intelligence (AI), with its excellent capabilities in big data processing and analysis, can play a crucial role in handling and processing interdisciplinary data and relationships and in better integrating and applying them in biofabrication. In recent years, the development of the semiconductor and integrated circuit industries has propelled the rapid advancement of computer processing power. An AI program can learn and iterate multiple times within a short period, thereby gaining strong automation capabilities for a specific research content or issue. To date, numerous AI programs have been applied to various processes around biofabrication, such as extracting biological information, designing and optimizing structures, intelligent cell sorting, optimizing biomaterials and processes, real-time monitoring and evaluation of models, accelerating the transformation and development of these technologies, and even changing traditional research patterns. This article reviews and summarizes the significant changes and advancements brought about by AI in biofabrication, and discusses its future application value and direction.

Mimicking the multilayered, anisotropic, elastic structure of cardiac tissues for controlled guidiance of 3D cellular orientation is essential in designing bionic scaffolds for cardiac tissue biofabrication. Here, a hierarchically organized, anisotropic, wavy and conductive polycaprolactone/Au scaffold was created in a facile fashion based on mechanical memory during fabrication. The bionic 3D scaffold shows good biocompatibility, excellent biomimetic mechanical properties that guide myoblast alignment, support the hyperelastic behavior observed in native cardiac muscle tissue, and promote myotube maturation, which holds potential for cardiac muscle engineering and the establishment of anin vitroculture platform for drug screening.