International Journal of Bioprinting最新文献

As the body's largest organ, the skin has important roles in barrier function, immune response, prevention of water loss and excretion of waste. Patients with extensive and severe skin lesions would die due to insufficient graftable skin. Commonly used treatments include autologous skin grafts, allogeneic/allogeneic skin grafts, cytoactive factors, cell therapy, and dermal substitutes. However, traditional treatment methods are still inadequate regarding skin repair time, treatment costs, and treatment results. In recent years, the rapid development of bioprinting technology has provided new ideas to solve the above-mentioned challenges. This review describes the principles of bioprinting technology and research advances in wound dressing and healing. This review features a data mining and statistical analysis of this topic through bibliometrics. The annual publications on this topic, participating countries, and institutions were used to understand the development history. Keyword analysis was used to understand the focus of investigation and challenges in this topic. According to bibliometric analysis, bioprinting in wound dressing and healing is in an explosive phase, and future research should focus on discovering new cell sources, innovative bioink development, and developing large-scale printing technology processes.

Cartilage damage is a common orthopedic disease, which can be caused by sports injury, obesity, joint wear, and aging, and cannot be repaired by itself. Surgical autologous osteochondral grafting is often required in deep osteochondral lesions to avoid the later progression of osteoarthritis. In this study, we fabricated a gelatin methacryloyl-marrow mesenchymal stem cells (GelMA-MSCs) scaffold by three-dimensional (3D) bioprinting. This bioink is capable of fast gel photocuring and spontaneous covalent cross-linking, which can maintain high viability of MSCs and provide a benign microenvironment to promote the interaction, migration, and proliferation of cells. In vivo experiments, further, proved that the 3D bioprinting scaffold can promote the regeneration of cartilage collagen fibers and have a remarkable effect on cartilage repair of rabbit cartilage injury model, which may represent a general and versatile strategy for precise engineering of cartilage regeneration system.

256Diabetes is an autoimmune disease that ensues when the pancreas does not deliver adequate insulin or when the body cannot react to the existing insulin. Type 1 diabetes is an autoimmune disease defined by continuous high blood sugar levels and insulin deficiency due to β-cell destruction in the islets of Langerhans (pancreatic islets). Long-term complications, such as vascular degeneration, blindness, and renal failure, result from periodic glucose-level fluctuations following exogenous insulin therapy. Nevertheless, the shortage of organ donors and the lifelong dependency on immunosuppressive drugs limit the transplantation of the entire pancreas or pancreas islet, which is the therapy for this disease. Although encapsulating pancreatic islets using multiple hydrogels creates a semi-privileged environment to prevent immune rejection, hypoxia that occurs in the core of the capsules is the main hindrance that should be solved. Bioprinting technology is an innovative process in advanced tissue engineering that allows the arranging of a wide array of cell types, biomaterials, and bioactive factors as a bioink to simulate the native tissue environment for fabricating clinically applicable bioartificial pancreatic islet tissue. Multipotent stem cells have the potential to be a possible solution for donor scarcity and can be a reliable source for generating autograft and allograft functional β-cells or even pancreatic islet-like tissue. The use of supporting cells, such as endothelial cells, regulatory T cells, and mesenchymal stem cells, in the bioprinting of pancreatic islet-like construct could enhance vasculogenesis and regulate immune activity. Moreover, scaffolds bioprinted using biomaterials that can release oxygen postprinting or enhance angiogenesis could increase the function of β-cells and the survival of pancreatic islets, which could represent a promising avenue.

Edible bird's nests (EBN)-the nests of swiftlet birds harvested from the wild- are high-end healthcare food in East Asia, while their excessive harvesting poses increasing ecological, environmental, and food safety concerns. Here, we report for the first time a tissue-engineering (TE) approach for fabricating EBNs substitutes by integrating the technologies of three-dimensional (3D) printing and live cell culture. The engineered products, tissue-engineered edible bird's nests (TeeBN), comprise two layers. The first is a feeding layer that encapsulates epithelial cells in 3D-printed biocompatible gelation scaffolds. These cells secrete bioactive ingredients, e.g., sialic acid and epidermal growth factors (EGF), recapitulating the natural production of these substances by birds. The second is a receiving layer, consisting of foodgrade natural polymers, e.g., polysaccharides, which mimics the building blocks of natural EBNs while biologically stabilizing the factors released from the feeding layer. In vitro characterizations demonstrate that the feeding layer facilitates 3D cell growth and functions, and the receiving layer (as the end product) contains the necessary nutrients expected from natural EBNs-while without harmful substances commonly detected in natural EBNs. Further, in vivo metabolomics studies in mice indicate that TeeBN showed a similar profile of serum metabolites as natural EBN, reflecting comparable nutritional effects. In summary, we innovatively developed a tissue engineering-based substitute for EBNs with comparable metabolic functions and minimized safety risks, opening a new avenue for producing delicacy food from laboratorial cell culture with 3D printing technology.

The application of three-dimensional (3D) bioprinting has increased in the biomedical field. The lack of bioinks with both biocompatibility and printability is still a problem to be solved. Silk fibroin materials have good biocompatibility and have a broad application prospect in the field of biomedical materials. At present, most research usually involves Bombyx mori silk fibroin (BSF). However, BSF has low cell adhesion. Compared with BSF, Antheraea pernyi silk fibroin (ASF) isolated from typical non-mulberry silk exhibits a unique arginine-glycine-aspartate (RGD) sequence with good cell adhesion enhancement. In this study, we developed a bioink based on ASF for digital light processing (DLP) 3D bioprinting. The ASF-based bioinks (ASF-MA) were produced by a methacryloylation process using methacrylic anhydride (MA) to achieve the properties of photopolymerization reaction. The ASF-MA hydrogel has mechanical properties, biocompatibility, and especially cell adhesion. Meanwhile, we found that the ASF-MA hydrogels promoted the adhesion, migration, and proliferation of S16 cells. Hence, the ASF-MA hydrogels had the potential applications in biomedical fields.

Intramembranous ossification (IMO) and endochondral ossification (ECO) are two pathways of bone regeneration. The regeneration of most bone, such as limb bone, trunk bone, and skull base bone, mainly occurs in the form of endochondral ossification, which has also become one of the effective ways for bone tissue engineering. In this work, we prepared a well-structured and biocompatible methacrylated gelatin/polymethacrylic acid (GelMA/PMAA) hydrogel by digital light processing (DLP) printing technology, which could effectively chelate iron ions and continuously activate the hypoxia-inducible factor-1 alpha (HIF-1α) signaling pathway to promote the process of endochondral ossification and angiogenesis. The incorporation of PMAA endowed the hydrogel with remarkable viscoelasticity and high efficacy in chelation of iron ions, giving rise to the activation of HIF-1α signaling pathway, improving chondrogenic differentiation in the early stage, and facilitating vascularization in the later stage and bone remodeling. Therefore, the findings have significant implications on DLP printing technology of endochondral osteogenesis induced by the iron-chelating property of biological scaffold, which will provide an effective way in the development of novel bone regeneration.

72Several studies have been conducted to investigate the feasibility of customized nasal masks produced by three-dimensional (3D) facial imaging and printing for continuous positive airway pressure in adults and in premature mannequin. In addition to replicating the entire process, we applied the customized nasal mask to a premature patient who weighed less than 1,000 g. Facial scanning was performed. The study masks were manufactured using stereolithography with a 3D printer model Form3BL (FormLABS). Elastic 50 resin was used as the material. We verified the feasibility of the correct transmission of non-invasive ventilation and found that the mask improved the respiratory parameters and reduced the need for supplemental oxygen. The fraction of inspired oxygen (FiO₂) was lowered from 45%, which was the requirement when the traditional mask is used, to almost 21% when the nasal mask was applied to the premature patient, who was either in incubator or in kangaroo position. In view of these results, a clinical trial is being launched to evaluate the safety and efficacy of 3D-printed masks in extremely low birth weight (ELBW) infants. 3D printing provides an alternative for obtaining customized masks that may be more suitable for non-invasive ventilation in ELBW infants than traditional masks.

The common characteristics that make scaffolds suitable for human tissue substitutes include high porosity, microscale features, and pores interconnectivity. Too often, however, these characteristics are limiting factors for the scalability of different fabrication approaches, particularly in bioprinting techniques, in which either poor resolution, small areas, or slow processes hinder practical use in certain applications. An excellent example is bioengineered scaffolds for wound dressings, in which microscale pores in large surface-to-volume ratio scaffolds must be manufactured - ideally fast, precise, and cheap, and where conventional printing methods do not readily meet both ends. In this work, we propose an alternative vat photopolymerization technique to fabricate centimeter-scale scaffolds without losing resolution. We used laser beam shaping to first modify the profile of the voxels in 3D printing, resulting in a technology we refer to as light sheet stereolithography (LS-SLA). For proof of concept, we developed a system from commercially available off-the-shelf components to demonstrate strut thicknesses up to 12.8 ± 1.8 μm, tunable pore sizes ranging from 36 μm to 150 μm, and scaffold areas up to 21.4 mm × 20.6 mm printed in a short time. Furthermore, the potential to fabricate more complex and three-dimensional scaffolds was demonstrated with a structure composed of six layers, each rotated by 45° with respect to the previous. Besides the demonstrated high resolution and achievable large scaffold sizes, we found that LS-SLA has great potential for scaling-up of applied oriented technology for tissue engineering applications.

Cellulose-containing residue from agar production was incorporated as a filler into soy protein-based hydrogels and revalorized without further purification. Rheological assessment of these hydrogels was carried out in order to confirm their shear-thinning behavior and their suitability for 3D printing. It was observed that all hydrogels behaved as weak gels, which are suitable for 3D printing and have good printability and shape fidelity. The addition of cellulose did not cause chemical crosslinking but physical interactions, which led to morphological changes, thereby promoting hardness and shape recovery of the 3D-printed products. The hydrogel with the highest residue content (8 wt %) showed the highest value (78%) in shape recovery. Furthermore, the physicochemical characterization of these 3D-printed products revealed that although they have high swelling capacity, they preserve their integrity in wet conditions. These results suggested the potential of the 3D-printed products developed using residues without further purification to promote circular economy, increasing the efficiency in resources utilization.

438Severe skin injuries can cause serious problems, which could affect the patient's normal life, if not dealt properly in a timely and effective manner. It is an urgent requirement to develop personalized wound dressings with excellent antibacterial activity and biocompatibility to match the shape of the wound to facilitate clinical application. In this study, a bioink (GAQ) based on gelatin (Gel)/sodium alginate (SA)/ quaternized chitosan (QCS) was prepared, and GAQ hydrogel dressing grafting with dopamine (GADQ) was fabricated by an extrusion three-dimensional (3D) printing technology. QCS was synthesized by modifying quaternary ammonium group on chitosan, and its structure was successfully characterized by nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectroscopy (FT-IR). Our results showed that the GADQ hydrogel dressing that was double-crosslinked by EDC/ NHS and Ca²⁺ had good tensile strength, considerable swelling ratio, and effective antioxidation properties. It also showed that GADQ1.5% had 93.17% and 91.06% antibacterial activity against Staphylococcus aureus and Escherichia coli, respectively. Furthermore, the relative survival ratios of fibroblast cells seeded on these hydrogels exceeded 350% after cultured for 7 days, which proved the biocompatibility of these hydrogels. Overall, this advanced 3D-printed GADQ1.5% hydrogels with effective antioxidation, excellent antibacterial activity and good biocompatibility had a considerable application potential for wound healing.