Poor Man's Atomic Layer Deposition of LiF for Additive-Free Growth of Lithium Columns.

Lithium metal is an ideal material for high-energy, cost-effective rechargeable energy storage systems. The thermodynamically unfavorable solid-liquid interface between the lithium metal and organic electrolyte necessitates the formation of an interlayer (SEI) which is known to have significant impact on lithium morphologies. Less well understood is the impact of the current collector substrate on the morphology of electrodeposited lithium. Here we report on the morphology of electrodeposited lithium as a function of the chemical pretreatments of the working electrode. We find that a copper substrate pretreatment with acidic solutions (sulfuric, oxalic, or acetic acid) results in the deposition of close-packed lithium columns with a uniform diameter. A controlled study of the pre-electrodeposited copper surface indicates that the formation of a 5-8 nm thick LiF protective layer on copper substrate from a chemical reaction between adsorbed surface water layer in acidic solutions and LiPF6 electrolyte is the key process in the electrochemical growth of lithium columns. We anticipate that this simple chemical approach can be generalized as a scalable, low-cost, additive-free substrate treatment method for depositing a LiF protective layer, broadly applicable in the development of uniform lithium films.

From cells to cars: Developing an electrochemical techniques and diagnostics course for new battery engineers.

We are a team of three battery researchers and engineers who are working with The Electrochemical Society to develop an "electrochemical techniques and diagnostics for batteries" curriculum, comprised of an online course and an in-person workshop. With a combined 40+ years of experience working in battery research and engineering, ranging from academia to electric vehicle manufacturing, we have noticed that there exists a gap in applied electrochemistry knowledge needed to train the rapidly expanding workforce of battery engineers and scientists. In this backstory, we explain the origin story of our team, our motivations for developing the course and the things we have learned in working together. We share our insights into the emerging electric vehicles business and why we believe electrochemistry education will shape the future of this industry.

Oxygen reduction electrocatalyst based on strongly coupled cobalt oxide nanocrystals and carbon nanotubes.

Electrocatalyst for oxygen reduction reaction (ORR) is crucial for a variety of renewable energy applications and energy-intensive industries. The design and synthesis of highly active ORR catalysts with strong durability at low cost is extremely desirable but remains challenging. Here, we used a simple two-step method to synthesize cobalt oxide/carbon nanotube (CNT) strongly coupled hybrid as efficient ORR catalyst by directly growing nanocrystals on oxidized multiwalled CNTs. The mildly oxidized CNTs provided functional groups on the outer walls to nucleate and anchor nanocrystals, while retaining intact inner walls for highly conducting network. Cobalt oxide was in the form of CoO due to a gas-phase annealing step in NH(3). The resulting CoO/nitrogen-doped CNT (NCNT) hybrid showed high ORR current density that outperformed Co(3)O(4)/graphene hybrid and commercial Pt/C catalyst at medium overpotential, mainly through a 4e reduction pathway. The metal oxide/carbon nanotube hybrid was found to be advantageous over the graphene counterpart in terms of active sites and charge transport. Last, the CoO/NCNT hybrid showed high ORR activity and stability under a highly corrosive condition of 10 M NaOH at 80 °C, demonstrating the potential of strongly coupled inorganic/nanocarbon hybrid as a novel catalyst system in oxygen depolarized cathode for chlor-alkali electrolysis.

Recovery and Reuse of Composite Cathode Binder in Lithium Ion Batteries.

Here, we investigate the recovery and reuse of polyvinylidene fluoride (PVDF) binders from both homemade and commercial cathode films in Li ion batteries. We find that PVDF solubility depends on whether the polymer is an isolated powder or cast into a composite film. A mixture of tetrahydrofuran:N-methyl-2-pyrrolidone (THF : NMP, 50 : 50 v/v) at 90 °C delaminates composite cathodes from Al current collectors and yields pure PVDF as characterized by 1 H nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), wide-angle X-ray scattering (WAXS), and scanning electron microscopy (SEM). PVDF recovered from Li ion cells post-cycling exhibits similar performance to pristine PVDF. These data suggest that PVDF can be extracted and reused during Li ion battery recycling while simultaneously eliminating the formation of HF etchants, providing an incentive for use in direct cathode recycling.

Evolving contact mechanics and microstructure formation dynamics of the lithium metal-Li7La3Zr2O12 interface.

The dynamic behavior of the interface between the lithium metal electrode and a solid-state electrolyte plays a critical role in all-solid-state battery performance. The evolution of this interface throughout cycling involves multiscale mechanical and chemical heterogeneity at the micro- and nano-scale. These features are dependent on operating conditions such as current density and stack pressure. Here we report the coupling of operando acoustic transmission measurements with nuclear magnetic resonance spectroscopy and magnetic resonance imaging to correlate changes in interfacial mechanics (such as contact loss and crack formation) with the growth of lithium microstructures during cell cycling. Together, the techniques reveal the chemo-mechanical behavior that governs lithium metal and Li7La3Zr2O12 interfacial dynamics at various stack pressure regimes and with voltage polarization.

High CD21 expression inhibits internalization of anti-CD19 antibodies and cytotoxicity of an anti-CD19-drug conjugate.

CD19 and CD21 (CR2) are co-receptors found on B-cells and various B-cell lymphomas, including non-Hodgkin lymphoma. To evaluate their suitability as targets for therapy of such lymphomas using internalization-dependent antibody-drug conjugates [such as antibody-4-(N-maleimidomethyl)cyclohexane-1-carboxylate, (N2'-deacetyl-N2'-(3-mercapto-1-oxopropyl)-maytansine) (MCC-DM1) conjugates, which require lysosomal degradation of the antibody moiety for efficacy], we examined uptake of antibodies to CD19 and CD21 in a panel of B-cell lines. Anti-CD21 antibodies were not sufficiently internalized even in the highest CD21-expressing Raji cells, resulting in lack of efficacy with anti-CD21-MCC-DM1 conjugates. Anti-CD19 antibody uptake was variable, and was unexpectedly negatively correlated with CD21 expression. Thus, high CD21-expressing Raji, ARH77 and primary B-cells only very slowly internalized anti-CD19 antibodies, while CD21-negative or low expressing cells, including Ramos and Daudi, rapidly internalized these antibodies in clathrin-coated vesicles followed by lysosomal delivery. Anti-CD19-MCC-DM1 caused greater cytotoxicity in the faster anti-CD19-internalizing cell lines, implying that the rate of lysosomal delivery and subsequent drug release is important. Furthermore, transfection of Ramos cells with CD21 impeded anti-CD19 uptake and decreased anti-CD19-MCC-DM1 efficacy, suggesting that CD21-negative tumours should respond better to such anti-CD19 conjugates. This may have possible clinical implications, as anti-CD21 immunohistochemistry revealed only approximately 30% of 54 diffuse large B-cell lymphoma patients lack CD21 expression.

Microtechnology and nanotechnology in nerve repair.

OBJECTIVE: This review will describe the novel contributions to the field of nerve repair from the emerging disciplines of microtechnology and nanotechnology. METHOD: This broad review will cover the advances described in the literature of the medical and biological fields and the engineering and physical sciences. The authors have also included their own work in this field. DISCUSSION: Microtechnology and nanotechnology are providing two fundamentally different pathways for pursuing nerve repair: (1) microstructured scaffolds to promote regeneration and (2) direct repair by reconnecting axons. In the first instance, many of the traditional techniques for microfabrication of microelectronics have been applied to the development of implantable tissue scaffolds with precisely formed architectures. Combined with nanotechnological capabilities to control their surface chemistries, these tissue constructs have been designed to create a microenvironment within nerve tissue to optimally promote the outgrowth of neurites. With some initial successes in animal models, these next generation tissue scaffolds may provide a marked improvement over traditional nerve grafts in the ability to overcome nerve degenerative processes and to coax nerve regeneration leading to restoration of at least some nerve function. A second, completely different repair strategy aims to directly repair nerves at the microscale by acutely reconnecting severed or damaged axons immediately after injury and potentially forestalling the usual downstream degenerative processes. This strategy will take advantage of the traditional capabilities of microfabrication to create microelectromechanical systems that will serve as ultramicrosurgical tools that can operate at the micron scale and reliably manipulate individual axons without incurring damage. To bring about some restoration of a nerve's function, axon repair will have to be performed repetitively on a large scale and soon after injury. Development work is currently underway to bring about the feasibility of this technique. CONCLUSION: With the emergence of microtechnology and nanotechnology, new methods for repairing nerves are being explored and developed. There have been two fundamental benefits from the technologies of the ultrasmall scale: (1) enhancement of regeneration using new tissue scaffold materials and architecture; (2) direct repair of nerves at the scale of single neurons and axons.

Microtechnology in medicine: the emergence of surgical microdevices.

With the emergence of technologies to fabricate and mass-produce microscale tools and micromachines, microsurgery stands to potentially benefit through the development of a fundamentally new class of instruments. These new instruments may provide the surgeon with access to the smallest reaches of the body and perform operations that are currently not possible with manually operated tools. These new devices can be variably constructed and configured based on a wide range of design possibilities and can be built to serve many different fundamental surgical functions requiring the manipulation and handling of small tissues and structures, including grasping, cutting, and monitoring. With these functionalities also comes a high degree of integration, allowing tools and space to be used efficiently. Adapted from the techniques of the microelectronics industry, the fabrication methods and materials produce structures that are mechanically strong and easy to reproduce on a large scale. Well-developed design and physical modeling tools mean that the process of instrument development and validation can be streamlined. Along with these new instruments comes the need to provide automated interfaces to effectively translate human operator intentions into the appropriate actuation and motion of these devices. These interfaces must include the capability to scale down human motions to the range of microns. Most likely, the operation of these new microsurgical devices will resemble the control schemes developed for robotic surgery. The control schemes will provide accurate motions while minimizing the chances of damaging tools or unnecessarily injuring tissues. Naturally, these new tools and surgical schemes will require a transition from the conventional paradigm. However, with new surgical capabilities that may allow direct intervention into the inner workings of a cell, MEMS and nanotechnology-based tools may become a crucial part of the arsenal for the next generation of surgeons. Invariably, future developments of this new class of instruments will depend in large part on needs identified by the surgeon and an understanding of the enabling properties of microtechnology and nanotechnology. Thus, recognition of the vast potentials of this new technology among clinicians will greatly help to accelerate the development and integration of new microdevices and novel procedures that address disease and injury with unprecedented precision.

High-throughput screening of hybridoma supernatants using multiplexed fluorescent cell barcoding on live cells.

With current available assay formats using either immobilized protein (ELISA, enzyme-linked immunosorbent assay) or immunostaining of fixed cells for primary monoclonal antibody (mAb) screening, researchers often fail to identify and characterize antibodies that recognize the native conformation of cell-surface antigens. Therefore, screening using live cells has become an integral and important step contributing to the successful identification of therapeutic antibody candidates. Thus the need for developing high-throughput screening (HTS) technologies using live cells has become a major priority for therapeutic mAb discovery and development. We have developed a novel technique called Multiplexed Fluorescent Cell Barcoding (MFCB), a flow cytometry-based method based upon the Fluorescent Cell Barcoding (FCB) technique and the Luminex fluorescent bead array system, but is applicable to high-through mAb screens on live cells. Using this technique in our system, we can simultaneously identify or characterize the antibody-antigen binding of up to nine unique fluorescent labeled cell populations in the time that it would normally take to process a single population. This has significantly reduced the amount of time needed for the identification of potential lead candidates. This new technology enables investigators to conduct large-scale primary hybridoma screens using flow cytometry. This in turn has allowed us to screen antibodies more efficiently than before and streamline identification and characterization of lead molecules.

Isolation of neuronal substructures and precise neural microdissection using a nanocutting device.

We describe a set of microfabricated nanocutting devices with a cutting edge of less than 20 nm radius of curvature that enables high precision microdissection and subcellular isolation of neuronal structures. With these devices, it is possible to isolate functional substructures from neurons in culture such as segments of axons and dendrites, dendritic spines and Nodes of Ranvier. By fine-tuning the mechanical compliance of these devices, they can also act as alternatives to costly laser capture microdissection workstations for harvesting specific neuronal populations from tissue sections for analysis. The small size of the device (1 mm2x100 microm) allows convenient insertion into researcher specific experimental set-ups. Its ease of use and possibility for batch fabrication makes this a highly effective and versatile tool for tissue microdissection and the microanalysis of neuronal function.

Physical models have gender-specific effects on student understanding of protein structure-function relationships.

Understanding how basic structural units influence function is identified as a foundational/core concept for undergraduate biological and biochemical literacy. It is essential for students to understand this concept at all size scales, but it is often more difficult for students to understand structure-function relationships at the molecular level, which they cannot as effectively visualize. Students need to develop accurate, 3-dimensional mental models of biomolecules to understand how biomolecular structure affects cellular functions at the molecular level, yet most traditional curricular tools such as textbooks include only 2-dimensional representations. We used a controlled, backward design approach to investigate how hand-held physical molecular model use affected students' ability to logically predict structure-function relationships. Brief (one class period) physical model use increased quiz score for females, whereas there was no significant increase in score for males using physical models. Females also self-reported higher learning gains in their understanding of context-specific protein function. Gender differences in spatial visualization may explain the gender-specific benefits of physical model use observed. © 2016 The Authors Biochemistry and Molecular Biology Education published by Wiley Periodicals, Inc. on behalf of International Union of Biochemistry and Molecular Biology, 44(4):326-335, 2016.

Conditional rescue of protein kinase C epsilon regulates ethanol preference and hypnotic sensitivity in adult mice.

Conventional gene targeting is a powerful tool to study the influence of specific genes on behavior. However, conclusions relevant for adult animals are limited by consequences of gene loss during development. Mice lacking protein kinase C epsilon (PKCepsilon) consume less alcohol and show greater acute sensitivity to alcohol than do wild-type mice. There are no selective inhibitors of PKCepsilon that can be administered systemically and cross the blood-brain barrier to test whether these phenotypes result from loss of PKCepsilon during development or in adulthood. Here we used conditional expression of PKCepsilon in the basal forebrain, amygdala, and cerebellum to rescue wild-type responses to alcohol in adult PKCepsilon(-/-) mice. Subsequent suppression of transgenic PKCepsilon restored PKCepsilon(-/-) behaviors. These findings establish that PKCepsilon signaling in the adult brain regulates alcohol consumption and sensitivity. If this extends to humans, then PKCepsilon inhibitors might prove useful as novel therapeutics for alcoholism.

Biomimetic technique for adhesion-based collection and separation of cells in a microfluidic channel.

A basic step in many biological assays is separating and isolating different types of cells from raw samples. To better meet these requirements in microfluidic devices for miniature biomedical analytical systems, an alternative method for separating cells has been devised by mimicking the physiological process of leukocyte recruitment to blood vessel walls: adhesive cell rolling and transient tethering. Reproducing these interactions for cells on surfaces of microstructured fluidic channels can serve to capture and concentrate cells and even to fractionate different cell types from a continuously flowing sample. To demonstrate this principle, two designs for microstructured fluidic channels were fabricated: an array of Square pillars and another with slender, Offset pillars. These structures were coated with E-selectin IgG chimera and the interactions of HL-60 and U-937 cells with these structures were characterized. With inflow of fluidic cell suspensions, the structures were able to efficiently capture and arrest cells directly from the rapid free stream flow. After capture, cells transit through the channel in three phases: cell rolling, cell tethering, and transient re-suspension in free stream flow before re-capture. Under these interactions, captured cells were enriched several hundred-fold from the original concentration. Additionally, among collected cells, the difference in flow-driven, adhesion-mediated cell transit in the Square design suggested that the two cell types could at least be partially fractionated.

AMG 595, an Anti-EGFRvIII Antibody-Drug Conjugate, Induces Potent Antitumor Activity against EGFRvIII-Expressing Glioblastoma.

Epidermal growth factor receptor variant III (EGFRvIII) is a cancer-specific deletion mutant observed in approximately 25% to 50% of glioblastoma multiforme (GBM) patients. An antibody drug conjugate, AMG 595, composed of the maytansinoid DM1 attached to a highly selective anti-EGFRvIII antibody via a noncleavable linker, was developed to treat EGFRvIII-positive GBM patients. AMG 595 binds to the cell surface and internalizes into the endo-lysosomal pathway of EGFRvIII-expressing cells. Incubation of AMG 595 with U251 cells expressing EGFRvIII led to potent growth inhibition. AMG 595 treatment induced significant tumor mitotic arrest, as measured by phospho-histone H3, in GBM subcutaneous xenografts expressing EGFRvIII. A single intravenous injection of AMG 595 at 17 mg/kg (250 µg DM1/kg) generated complete tumor regression in the U251vIII subcutaneous xenograft model. AMG 595 mediated tumor regression in the D317 subcutaneous xenograft model that endogenously expresses EGFRvIII. Finally, AMG 595 treatment inhibited the growth of D317 xenografts orthotopically implanted into the brain as determined by magnetic resonance imaging. These results demonstrate that AMG 595 is a promising candidate to evaluate in EGFRvIII-expressing GBM patients.

SLC46A3 Is Required to Transport Catabolites of Noncleavable Antibody Maytansine Conjugates from the Lysosome to the Cytoplasm.

Antibody-drug conjugates (ADC) target cytotoxic drugs to antigen-positive cells for treating cancer. After internalization, ADCs with noncleavable linkers are catabolized to amino acid-linker-warheads within the lysosome, which then enter the cytoplasm by an unknown mechanism. We hypothesized that a lysosomal transporter was responsible for delivering noncleavable ADC catabolites into the cytoplasm. To identify candidate transporters, we performed a phenotypic shRNA screen with an anti-CD70 maytansine-based ADC. This screen revealed the lysosomal membrane protein SLC46A3, the genetic attenuation of which inhibited the potency of multiple noncleavable antibody-maytansine ADCs, including ado-trastuzumab emtansine. In contrast, the potencies of noncleavable ADCs carrying the structurally distinct monomethyl auristatin F were unaffected by SLC46A3 attenuation. Structure-activity experiments suggested that maytansine is a substrate for SLC46A3. Notably, SLC46A3 silencing led to relative increases in catabolite concentrations in the lysosome. Taken together, our results establish SLC46A3 as a direct transporter of maytansine-based catabolites from the lysosome to the cytoplasm, prompting further investigation of SLC46A3 as a predictive response marker in breast cancer specimens.

Quantitative comparison of long-wavelength Alexa Fluor dyes to Cy dyes: fluorescence of the dyes and their bioconjugates.

Amine-reactive N-hydroxysuccinimidyl esters of Alexa Fluor fluorescent dyes with principal absorption maxima at about 555 nm, 633 nm, 647 nm, 660 nm, 680 nm, 700 nm, and 750 nm were conjugated to antibodies and other selected proteins. These conjugates were compared with spectrally similar protein conjugates of the Cy3, Cy5, Cy5.5, Cy7, DY-630, DY-635, DY-680, and Atto 565 dyes. As N-hydroxysuccinimidyl ester dyes, the Alexa Fluor 555 dye was similar to the Cy3 dye, and the Alexa Fluor 647 dye was similar to the Cy5 dye with respect to absorption maxima, emission maxima, Stokes shifts, and extinction coefficients. However, both Alexa Fluor dyes were significantly more resistant to photobleaching than were their Cy dye counterparts. Absorption spectra of protein conjugates prepared from these dyes showed prominent blue-shifted shoulder peaks for conjugates of the Cy dyes but only minor shoulder peaks for conjugates of the Alexa Fluor dyes. The anomalous peaks, previously observed for protein conjugates of the Cy5 dye, are presumably due to the formation of dye aggregates. Absorption of light by the dye aggregates does not result in fluorescence, thereby diminishing the fluorescence of the conjugates. The Alexa Fluor 555 and the Alexa Fluor 647 dyes in protein conjugates exhibited significantly less of this self-quenching, and therefore the protein conjugates of Alexa Fluor dyes were significantly more fluorescent than those of the Cy dyes, especially at high degrees of labeling. The results from our flow cytometry, immunocytochemistry, and immunohistochemistry experiments demonstrate that protein-conjugated, long-wavelength Alexa Fluor dyes have advantages compared to the Cy dyes and other long-wavelength dyes in typical fluorescence-based cell labeling applications.

Apo2L/TRAIL and the death receptor 5 agonist antibody AMG 655 cooperate to promote receptor clustering and antitumor activity.

Death receptor agonist therapies have exhibited limited clinical benefit to date. Investigations into why Apo2L/TRAIL and AMG 655 preclinical data were not predictive of clinical response revealed that coadministration of Apo2L/TRAIL with AMG 655 leads to increased antitumor activity in vitro and in vivo. The combination of Apo2L/TRAIL and AMG 655 results in enhanced signaling and can sensitize Apo2L/TRAIL-resistant cells. Structure determination of the Apo2L/TRAIL-DR5-AMG 655 ternary complex illustrates how higher order clustering of DR5 is achieved when both agents are combined. Enhanced agonism generated by combining Apo2L/TRAIL and AMG 655 provides insight into the limited efficacy observed in previous clinical trials and suggests testable hypotheses to reconsider death receptor agonism as a therapeutic strategy.

An ultrafast nickel-iron battery from strongly coupled inorganic nanoparticle/nanocarbon hybrid materials.

Ultrafast rechargeable batteries made from low-cost and abundant electrode materials operating in safe aqueous electrolytes could be attractive for electrochemical energy storage. If both high specific power and energy are achieved, such batteries would be useful for power quality applications such as to assist propelling electric vehicles that require fast acceleration and intense braking. Here we develop a new type of Ni-Fe battery by employing novel inorganic nanoparticle/graphitic nanocarbon (carbon nanotubes and graphene) hybrid materials as electrode materials. We successfully increase the charging and discharging rates by nearly 1,000-fold over traditional Ni-Fe batteries while attaining high energy density. The ultrafast Ni-Fe battery can be charged in ~2 min and discharged within 30 s to deliver a specific energy of 120 Wh kg(-1) and a specific power of 15 kW kg(-1). These features suggest a new generation of Ni-Fe batteries as novel devices for electrochemical energy storage.

Axon repair: surgical application at a subcellular scale.

Injury to the nervous system is a common occurrence after trauma. Severe cases of injury exact a tremendous personal cost and place a significant healthcare burden on society. Unlike some tissues in the body that exhibit self healing, nerve cells that are injured, particularly those in the brain and spinal cord, are incapable of regenerating circuits by themselves to restore neurological function. In recent years, researchers have begun to explore whether micro/nanoscale tools and materials can be used to address this major challenge in neuromedicine. Efforts in this area have proceeded along two lines. One is the development of new nanoscale tissue scaffold materials to act as conduits and stimulate axon regeneration. The other is the use of novel cellular-scale surgical micro/nanodevices designed to perform surgical microsplicing and the functional repair of severed axons. We discuss results generated by these two approaches and hurdles confronting both strategies.

A tribute to Dr. David Kline: a new approach to an old peripheral nerve problem--splicing instead of regenerating disrupted axons.

OBJECTIVE: Our goal is to develop a novel method to repair damaged axons. This method relies on acutely restoring axonal continuity rather than the traditional approach of promoting axonal regeneration. METHODS: Micro- and nanoechnological methods, in combination with focal application of electrical fields, are applied to individual and groups of axons both in vitro and in vivo. RESULTS: Application of these techniques has permitted micromanipulation of axons at the cellular level and fusion of axonal membranes. CONCLUSION: Although a great deal more work is necessary, our findings suggest that it may one day be possible to repair acutely disrupted axons by splicing their membranes back together.