To achieve good rate capability of lithium metal anodes for high-energy-density batteries, one fundamental challenge is the slow lithium diffusion at the interface. Here we report an interpenetrated, ...three-dimensional lithium metal/lithium tin alloy nanocomposite foil realized by a simple calendering and folding process of lithium and tin foils, and spontaneous alloying reactions. The strong affinity between the metallic lithium and lithium tin alloy as mixed electronic and ionic conducting networks, and their abundant interfaces enable ultrafast charger diffusion across the entire electrode. We demonstrate that a lithium/lithium tin alloy foil electrode sustains stable lithium stripping/plating under 30 mA cm
and 5 mAh cm
with a very low overpotential of 20 mV for 200 cycles in a commercial carbonate electrolyte. Cycled under 6 C (6.6 mA cm
), a 1.0 mAh cm
LiNi
Co
Mn
O
electrode maintains a substantial 74% of its capacity by pairing with such anode.
The propensity of lithium dendrite formation during the charging process of lithium metal batteries is linked to inhomogeneity on the lithium surface layer. The high reactivity of lithium and the ...complex surface structure of the native layer create “hot spots” for fast dendritic growth. Here, it is demonstrated that a fundamental restructuring of the lithium surface in the form of lithium silicide (LixSi) can effectively eliminate the surface inhomogeneity on the lithium surface. In situ optical microscopic study is carried out to monitor the electrochemical deposition of lithium on the LixSi‐modified lithium electrodes and the bare lithium electrode. It is observed that a much more uniform lithium dissolution/deposition on the LixSi‐modified lithium anode can be achieved as compared to the bare lithium electrode. Full cells paring the modified lithium anode with sulfur and LiFePO4 cathodes show excellent electrochemical performances in terms of rate capability and cycle stability. Compatibility of the anode enrichment method with mass production process also offers a practical way for enabling lithium metal anode for next‐generation lithium batteries.
A lithium silicide enriched protection layer is demonstrated to suppress the growth of lithium dendrites, uniformly distribute the applied current, and mitigate the parasitic side reactions in lithium metal batteries.
Cell–cell interaction accounts for one of the most influential factors affecting the viability and functionality of cell‐based tissue models. In this respect, various methods capable of producing ...micro‐patterns with cell spheroids are introduced to simultaneously improve contact‐dependent and ‐independent cell‐cell interactions. However, no method has yet been designed to effectively generate precise 3D patterns with multiple spheroid types. In this study, a new high‐precision and convenient 3D spheroid printing technology is developed, designated as 3D bio‐dot printing. This new technique is designed to produce cell‐laden, non‐adhesive micro‐pores within 3D structures to allow cell spheroids to be induced at printed sites. Experimental results show that various cell types, including hepatocytes, pancreatic β‐cells, and breast cancer cells, can be employed for the in situ formation of cell spheroids, and 3D freeform structures with multiple spheroid types can be printed. Moreover, this novel technology can also be used for performing 3D invasion assays. More importantly, it ensures that the precise control of spheroid size and position is achieved at micrometer scale. Finally, the usefulness of this novel technology is demonstrated by producing multicellular micro‐patterns with primary hepatocyte spheroids and endothelial cells, that exhibit significantly improved long‐term hepatic function and drug metabolism.
A new, high‐precision 3D cell spheroid printing technique, named 3D bio‐dot printing, is presented. The new technique exhibits convenient, precise, and 3D producible results with multiple cell spheroids, and can be applied to 3D spheroid invasion assays. Its application to hepatic models demonstrates that the technique can significantly improve long‐term hepatic function and drug metabolism through precise patterning with cell spheroids.
A bioengineered skeletal muscle tissue as an alternative for autologous tissue flaps, which mimics the structural and functional characteristics of the native tissue, is needed for reconstructive ...surgery. Rapid progress in the cell-based tissue engineering principle has enabled in vitro creation of cellularized muscle-like constructs; however, the current fabrication methods are still limited to build a three-dimensional (3D) muscle construct with a highly viable, organized cellular structure with the potential for a future human trial. Here, we applied 3D bioprinting strategy to fabricate an implantable, bioengineered skeletal muscle tissue composed of human primary muscle progenitor cells (hMPCs). The bioprinted skeletal muscle tissue showed a highly organized multi-layered muscle bundle made by viable, densely packed, and aligned myofiber-like structures. Our in vivo study presented that the bioprinted muscle constructs reached 82% of functional recovery in a rodent model of tibialis anterior (TA) muscle defect at 8 weeks of post-implantation. In addition, histological and immunohistological examinations indicated that the bioprinted muscle constructs were well integrated with host vascular and neural networks. We demonstrated the potential of the use of the 3D bioprinted skeletal muscle with a spatially organized structure that can reconstruct the extensive muscle defects.
A challenge for tissue engineering is producing three-dimensional (3D), vascularized cellular constructs of clinically relevant size, shape and structural integrity. We present an integrated ...tissue-organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape. Mechanical stability is achieved by printing cell-laden hydrogels together with biodegradable polymers in integrated patterns and anchored on sacrificial hydrogels. The correct shape of the tissue construct is achieved by representing clinical imaging data as a computer model of the anatomical defect and translating the model into a program that controls the motions of the printer nozzles, which dispense cells to discrete locations. The incorporation of microchannels into the tissue constructs facilitates diffusion of nutrients to printed cells, thereby overcoming the diffusion limit of 100-200 μm for cell survival in engineered tissues. We demonstrate capabilities of the ITOP by fabricating mandible and calvarial bone, cartilage and skeletal muscle. Future development of the ITOP is being directed to the production of tissues for human applications and to the building of more complex tissues and solid organs.
Understanding the local cation order in the crystal structure and its correlation with electrochemical performances has advanced the development of high‐energy Mn‐rich cathode materials for Li‐ion ...batteries, notably Li‐ and Mn‐rich layered cathodes (LMR, e.g., Li1.2Ni0.13Mn0.54Co0.13O2) that are considered as nanocomposite layered materials with C2/m Li2MnO3‐type medium‐range order (MRO). Moreover, the Li‐transport rate in high‐capacity Mn‐based disordered rock‐salt (DRX) cathodes (e.g., Li1.2Mn0.4Ti0.4O2) is found to be influenced by the short‐range order of cations, underlining the importance of engineering the local cation order in designing high‐energy materials. Herein, the nanocomposite is revealed, with a heterogeneous nature (like MRO found in LMR) of ultrahigh‐capacity partially ordered cathodes (e.g., Li1.68Mn1.6O3.7F0.3) made of distinct domains of spinel‐, DRX‐ and layered‐like phases, contrary to conventional single‐phase DRX cathodes. This multi‐scale understanding of ordering informs engineering the nanocomposite material via Ti doping, altering the intra‐particle characteristics to increase the content of the rock‐salt phase and heterogeneity within a particle. This strategy markedly improves the reversibility of both Mn‐ and O‐redox processes to enhance the cycling stability of the partially ordered DRX cathodes (nearly ≈30% improvement of capacity retention). This work sheds light on the importance of nanocomposite engineering to develop ultrahigh‐performance, low‐cost Li‐ion cathode materials.
The multi‐phase heterogeneous nature of ultrahigh‐energy Mn‐based partially disordered cathodes is revealed by combined experimental and computational studies. This fundamental understanding enables the novel nanocomposite design, which controls a phase fraction within a single particle. Consequently, T30 cathode via a nanocomposite engineering shows more reversible redox properties and a superior cycle retention, showing new insights into developing advanced Mn‐based cathodes.
Display omitted
Advancement of bioprinting technology is limited by the availability of materials that both facilitate bioprinting logistics as well as support cell viability and function by ...providing tissue-specific cues. Herein we describe a modular hyaluronic acid (HA) and gelatin-based hydrogel toolbox comprised of a 2-crosslinker, 2-stage polymerization technique, and the capability to provide tissue specific biochemically and mechanically accurate signals to cells within biofabricated tissue constructs. First, we prepared and characterized several tissue-derived decellularized extracellular matrix-based solutions, which contain complex combinations of growth factors, collagens, glycosaminoglycans, and elastin. These solutions can be incorporated into bioinks to provide the important biochemical cues of different tissue types. Second, we employed combinations of PEG-based crosslinkers with varying molecular weights, geometries (linear, 4-arm, and 8-arm), and functional groups to yield hydrogel bioinks that supported extrusion bioprinting and the capability to achieve final construct shear stiffness values ranging from approximately 100Pa to 20kPa. Lastly, we integrated these hydrogel bioinks with a 3-D bioprinting platform, and validated their use by bioprinting primary liver spheroids in a liver-specific bioink to create in vitro liver constructs with high cell viability and measurable functional albumin and urea output. This hydrogel bioink system has the potential to be a versatile tool for biofabrication of a wide range of tissue construct types.
Biochemical and mechanical factors both have important implications in guiding the behavior of cells in vivo, yet both realms are rarely considered together in the context of biofabrication in vitro tissue construct models. We describe a modular hydrogel system that (1) facilitates extrusion bioprinting of cell-laden hydrogels, (2) incorporates tissue-specific factors derived from decellularized tissue extracellular matrix, thus mimicking biochemical tissue profile, and (3) allows control over mechanical properties to mimic the tissue stiffness. We believe that employing this technology to attend to both the biochemical and mechanical profiles of tissues, will allow us to more accurately recapitulate the in vivo environment of tissues while creating functional 3-D in vitro tissue constructs that can be used as disease models, personalized medicine, and in vitro drug and toxicology screening systems.
Many drugs have progressed through preclinical and clinical trials and have been available - for years in some cases - before being recalled by the FDA for unanticipated toxicity in humans. One ...reason for such poor translation from drug candidate to successful use is a lack of model systems that accurately recapitulate normal tissue function of human organs and their response to drug compounds. Moreover, tissues in the body do not exist in isolation, but reside in a highly integrated and dynamically interactive environment, in which actions in one tissue can affect other downstream tissues. Few engineered model systems, including the growing variety of organoid and organ-on-a-chip platforms, have so far reflected the interactive nature of the human body. To address this challenge, we have developed an assortment of bioengineered tissue organoids and tissue constructs that are integrated in a closed circulatory perfusion system, facilitating inter-organ responses. We describe a three-tissue organ-on-a-chip system, comprised of liver, heart, and lung, and highlight examples of inter-organ responses to drug administration. We observe drug responses that depend on inter-tissue interaction, illustrating the value of multiple tissue integration for in vitro study of both the efficacy of and side effects associated with candidate drugs.
The FDA-approved small-molecule drug dasatinib is currently used as a treatment for chronic myeloid leukemia (CML). However, the effects of dasatinib on microglial and/or astrocytic neuroinflammatory ...responses and its mechanism of action have not been studied in detail.
BV2 microglial cells, primary astrocytes, or primary microglial cells were treated with dasatinib (100 or 250 nM) or vehicle (1% DMSO) for 30 min or 2 h followed by lipopolysaccharide (LPS; 200 ng/ml or 1 μg/ml) or PBS for 5.5 h. RT-PCR, real-time PCR; immunocytochemistry; subcellular fractionation; and immunohistochemistry were subsequently conducted to determine the effects of dasatinib on LPS-induced neuroinflammation. In addition, wild-type mice were injected with dasatinib (20 mg/kg, intraperitoneally (i.p.) daily for 4 days or 20 mg/kg, orally administered (p.o.) daily for 4 days or 2 weeks) or vehicle (4% DMSO + 30% polyethylene glycol (PEG) + 5% Tween 80), followed by injection with LPS (10 mg/kg, i.p.) or PBS. Then, immunohistochemistry was performed, and plasma IL-6, IL-1β, and TNF-α levels were analyzed by ELISA.
Dasatinib regulates LPS-induced proinflammatory cytokine and anti-inflammatory cytokine levels in BV2 microglial cells, primary microglial cells, and primary astrocytes. In BV2 microglial cells, dasatinib regulates LPS-induced proinflammatory cytokine levels by regulating TLR4/AKT and/or TLR4/ERK signaling. In addition, intraperitoneal injection and oral administration of dasatinib suppress LPS-induced microglial/astrocyte activation, proinflammatory cytokine levels (including brain and plasma levels), and neutrophil rolling in the brains of wild-type mice.
Our results suggest that dasatinib modulates LPS-induced microglial and astrocytic activation, proinflammatory cytokine levels, and neutrophil rolling in the brain.
Display omitted
•A new bio-inspired design for PDMS sponge has been proposed to improve the absorption capacity for oil-water separation.•The concept of the water absorption and storage functions of ...cacti plant was applied in designing the PDMS sponge.•The sponge with microscale architecture was fabricated by 3D printing technology.•The new design showed an absorption capacity increased by about 3.7 times in the test of oil-water separation.
Oil spills from disasters such as the sinking of ships and the discharge of oily wastes cause serious environmental problems. Polydimethylsiloxane(PDMS) sponges are valuable tools for isolating spilled oil. Here, we propose new PDMS sponges with bio-inspired design and enhanced absorption capacities. 3D printing was used to produce templates having negative designs, and after being filled with PDMS, the templates were selectively dissolved. Through this, PDMS sponges with well-interconnected and controlled porosities were produced within 10% error. The wettability of sponges with various pore sizes and line widths was investigated. The surfaces were found to be highly hydrophobic, with water contact angles of 100-143°, and oleophilic, with oil contact angles of ∼0°. The sponge fabricated with line width of 200 μm and pore size of 400 μm showed the highest hydrophobicity and oleophilicity. These parameters were used to produce the surfaces of hollow sponges having bio-inspired design that mimics the water absorption and storage functions of cactus. Repeated oil-water separation testing was conducted, and the absorption capacities were compared with those of non-hollow and conventional sponges. The new design showed absorption capacity up to 3.7 times that of the sponges. The bio-inspired PDMS sponge provides a significant advance in oil–water separation ability.
PDF
