Selective enrichment of electrogenic bacteria for fuel cell application: Enumerating microbial dynamics using MiSeq platform

This study is intended to examine the effect of pretreatment on selective enrichment of electrogenic bacteria from mixed culture. It has been observed that the iodopropane and heat-shock pretreatments suppress the growth of non-exoelectrons, while selecting only a limited number of strains belonging to genera Xanthomonas, Pseudomonas and Prevotella while untreated control inoculum showed more diverse community comprising of both exoelectrogens and non-exoelectrogens. High power output was observed in iodopropane (180mW/m(2)) pretreated microbial fuel cell (MFC) compared to heat-shock pretreated MFC (128mW/m(2)) and untreated control (92mW/m(2)). Coulombic efficiency of iodopropane and heat-shock pretreated MFC was higher compared to untreated control MFC, while drop in pH and volatile fatty acids (VFA) production was less in iodopropane pretreated MFC signifying the shifts in bacterial community structure toward electrogenesis instead of fermentation. These results signify the role of iodopropane and heat pretreatments on enrichment of electrogenic bacteria for fuel cell application.

Case Report: Industrial X-Ray Injury Treated With Non-Cultured Autologous Adipose-Derived Stromal Vascular Fraction (SVF)

Local cutaneous injuries induced by ionizing radiation (IR) are difficult to treat. Many have reported local injection of adipose-derived stromal vascular fraction (SVF), often with additional therapies, as an effective treatment of IR-induced injury even after other local therapies have failed. The authors report a case of a locally recurrent, IR-induced wound that was treated with autologous, non-cultured SVF without other concurrent therapy. A nondestructive testing technician was exposed to 130 kVp x rays to his non-dominant right thumb on 5 October 2011. The wound healed 4 mo after initial conservative therapy with oral/topical α-tocopherol, oral pentoxifylline, naproxen sodium, low-dose oral steroids, topical steroids, hyperbaric oxygen therapy (HBOT), oral antihistamines, and topical aloe vera. Remission lasted approximately 17 mo with one minor relapse in July 2012 after minimal trauma and subsequent healing. Aggressive wound breakdown during June 2013 required additional therapy with HBOT. An erythematous, annular papule developed over the following 12 mo (during which time the patient was not undergoing prescribed treatment). Electron paramagnetic resonance (EPR) done more than 2 mo after exposure to IR revealed dose estimates of 14 ± 3 Gy and 19 ± 6 Gy from two centers using different EPR techniques. The patient underwent debridement of the 0.5 cm papular area, followed by SVF injection into and around the wound bed and throughout the thumb without complication. Eleven months post SVF injection, the patient has been essentially asymptomatic with an intact integument. These results raise the possibility of prolonged benefit from SVF therapy without the use of cytokines. Since there is currently no consensus on the use of isolated SVF therapy in chronic, local IR-induced injury, assessment of this approach in an appropriately powered, controlled trial in experimental animals with local radiation injury appears to be indicated.

Harvesting of microalgal biomass: Efficient method for flocculation through pH modulation

Harvesting of the micro alga Chlorococcum sp. R-AP13 through autoflocculation, chemical flocculants or by change in medium pH was evaluated. Surface charge of algal cells changed in response to the method used and affected flocculation efficiency. While aluminum sulfate and FeCl3 supported 87% and 92% efficiency, auto flocculation could recover 75% of biomass in 10min. Maximum efficiency (94%) was obtained with change in medium pH from 8.5 to 12.0 achieved through addition of 40mgl(-1) of NaOH. Since high concentrations of FeCl3 and AlSO4 were toxic to the cells, flocculation induced by pH change may be considered the most effective strategy. Residual medium after flocculation could be reused efficiently for algal cultivation, minimizing the demand for fresh water.

Photoacoustic Imaging in Oncology: Translational Preclinical and Early Clinical Experience

Photoacoustic imaging has evolved into a clinically translatable platform with the potential to complement existing imaging techniques for the management of cancer, including detection, characterization, prognosis, and treatment monitoring. In photoacoustic imaging, tissue is optically excited to produce ultrasonographic images that represent a spatial map of optical absorption of endogenous constituents such as hemoglobin, fat, melanin, and water or exogenous contrast agents such as dyes and nanoparticles. It can therefore provide functional and molecular information that allows noninvasive soft-tissue characterization. Photoacoustic imaging has matured over the years and is currently being translated into the clinic with various clinical studies underway. In this review, the current state of photoacoustic imaging is presented, including techniques and instrumentation, followed by a discussion of potential clinical applications of this technique for the detection and management of cancer. (©) RSNA, 2016.

Three-dimensional Printing in the Intestine

Intestinal transplantation remains a life-saving option for patients with severe intestinal failure. With the advent of advanced tissue engineering techniques, great strides have been made toward manufacturing replacement tissues and organs, including the intestine, which aim to avoid transplant-related complications. The current paradigm is to seed a biocompatible support material (scaffold) with a desired cell population to generate viable replacement tissue. Although this technique has now been extended by the three-dimensional (3D) printing of geometrically complex scaffolds, the overall approach is hindered by relatively slow turnover and negative effects of residual scaffold material, which affects final clinical outcome. Methods recently developed for scaffold-free 3D bioprinting may overcome such obstacles and should allow for rapid manufacture and deployment of "bioprinted organs." Much work remains before 3D bioprinted tissues can enter clinical use. In this brief review we examine the present state and future perspectives of this nascent technology before full clinical implementation.

New prospects for targeting telomerase beyond the telomere

Telomerase activity is responsible for the maintenance of chromosome end structures (telomeres) and cancer cell immortality in most human malignancies, making telomerase an attractive therapeutic target. The rationale for targeting components of the telomerase holoenzyme has been strengthened by accumulating evidence indicating that these molecules have extra-telomeric functions in tumour cell survival and proliferation. This Review discusses current knowledge of the biogenesis, structure and multiple functions of telomerase-associated molecules intertwined with recent advances in drug discovery approaches. We also describe the fertile ground available for the pursuit of next-generation small-molecule inhibitors of telomerase.

MicroRNA degeneracy and pluripotentiality within a Lavallière-tie architecture confers robustness to gene expression networks

Modularity, feedback control, functional redundancy and bowtie architecture have been proposed as key factors that confer robustness to complex biological systems. MicroRNAs (miRNAs) are highly conserved but functionally dispensable. These antinomic properties suggest that miRNAs fine-tune gene expression rather than act as genetic switches. We synthesize published and unpublished data and hypothesize that miRNA pluripotentiality acts to buffer gene expression, while miRNA degeneracy tunes the expression of targets, thus providing robustness to gene expression networks. Furthermore, we propose a Lavallière-tie architecture by integrating signal transduction, miRNAs and protein expression data to model complex gene expression networks.

Synthetic and natural consensus design for engineering charge within an affibody targeting epidermal growth factor receptor

Protein ligand charge can impact physiological delivery with charge reduction often benefiting performance. Yet neutralizing mutations can be detrimental to protein function. Herein, three approaches are evaluated to introduce charged-to-neutral mutations of three cations and three anions within an affibody engineered to bind epidermal growth factor receptor. These approaches-combinatorial library sorting or consensus design, based on natural homologs or library-sorted mutants-are used to identify mutations with favorable affinity, stability, and recombinant yield. Consensus design, based on 942 affibody homologs, yielded a mutant of modest function (Kd  = 11 ±4 nM, Tm  = 62°C, and yield = 4.0 ± 0.8 mg/L as compared to 5.3 ± 1.7 nM, 71°C, and 3.5 ± 0.3 mg/L for the parental affibody). Extension of consensus design to 10 additional mutants exhibited varied performance including a substantially improved mutant (Kd  = 6.9 ± 1.4 nM, Tm  = 71°C, and 12.7 ± 0.9 mg/L yield). Sorting a homolog-based combinatorial library of 7 × 10(5) mutants generated a distribution of mutants with lower stability and yield, but did identify one strongly binding variant (Kd  = 1.2 ± 0.3 nM, Tm  = 69°C, and 6.0 ± 0.4 mg/L yield). Synthetic consensus design, based on the amino acid distribution in functional library mutants, yielded higher affinities (P = 0.05) with comparable stabilities and yields. The best of four analyzed clones had Kd  = 1.7 ± 0.5 nM, Tm  = 68°C, and 7.0 ± 0.5 mg/L yield. While all three approaches were effective in creating targeted affibodies with six charged-to-neutral mutations, synthetic consensus design proved to be the most robust. Synthetic consensus design provides a valuable tool for ligand engineering, particularly in the context of charge manipulation. Biotechnol. Bioeng. 2016;113: 1628-1638. © 2016 Wiley Periodicals, Inc.

Superporous Poly(ethylene glycol) Diacrylate Cryogel with a Defined Elastic Modulus for Prostate Cancer Cell Research

The physical and mechanical properties of the tumor microenvironment are crucial for the growth, differentiation and migration of cancer cells. However, such microenvironment is not found in the geometric constraints of 2D cell culture systems used in many cancer studies. Prostate cancer research, in particular, suffers from the lack of suitable in vitro models. Here a 3D superporous scaffold is described with thick pore walls in a mechanically stable and robust architecture to support prostate tumor growth. This scaffold is generated from the cryogelation of poly(ethylene glycol) diacrylate to produce a defined elastic modulus for prostate tumor growth. Lymph node carcinoma of the prostate (LNCaP) cells show a linear growth over 21 d as multicellular tumor spheroids in such a scaffold with points of attachments to the walls of the scaffold. These LNCaP cells respond to the growth promoting effects of androgens and demonstrate a characteristic cytoplasmic-nuclear translocation of the androgen receptor and androgen-dependent gene expression. Compared to 2D cell culture, the expression or androgen response of prostate cancer specific genes is greatly enhanced in the LNCaP cells in this system. This scaffold is therefore a powerful tool for prostate cancer studies with unique advantages over 2D cell culture systems.

Engineered biosynthesis of biodegradable polymers

Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers.

Boosting Power Density of Microbial Fuel Cells with 3D Nitrogen-Doped Graphene Aerogel Electrode

A 3D nitrogen-doped graphene aerogel (N-GA) as an anode material for microbial fuel cells (MFCs) is reported. Electron microscopy images reveal that the N-GA possesses hierarchical porous structure that allows efficient diffusion of both bacterial cells and electron mediators in the interior space of 3D electrode, and thus, the colonization of bacterial communities. Electrochemical impedance spectroscopic measurements further show that nitrogen doping considerably reduces the charge transfer resistance and internal resistance of GA, which helps to enhance the MFC power density. Importantly, the dual-chamber milliliter-scale MFC with N-GA anode yields an outstanding volumetric power density of 225 ± 12 W m^-3 normalized to the total volume of the anodic chamber (750 ± 40 W m^-3 normalized to the volume of the anode). These power densities are the highest values report for milliliter-scale MFCs with similar chamber size (25 mL) under the similar measurement conditions. The 3D N-GA electrode shows great promise for improving the power generation of MFC devices.

Biomimetic Extracellular Environment Based on Natural Origin Polyelectrolyte Multilayers

Surface modification of biomaterials is a well-known approach to enable an adequate biointerface between the implant and the surrounding tissue, dictating the initial acceptance or rejection of the implantable device. Since its discovery in early 1990s layer-by-layer (LbL) approaches have become a popular and attractive technique to functionalize the biomaterials surface and also engineering various types of objects such as capsules, hollow tubes, and freestanding membranes in a controllable and versatile manner. Such versatility enables the incorporation of different nanostructured building blocks, including natural biopolymers, which appear as promising biomimetic multilayered systems due to their similarity to human tissues. In this review, the potential of natural origin polymer-based multilayers is highlighted in hopes of a better understanding of the mechanisms behind its use as building blocks of LbL assembly. A deep overview on the recent progresses achieved in the design, fabrication, and applications of natural origin multilayered films is provided. Such films may lead to novel biomimetic approaches for various biomedical applications, such as tissue engineering, regenerative medicine, implantable devices, cell-based biosensors, diagnostic systems, and basic cell biology.

Harmful Effects of Leukocyte-Rich Platelet-Rich Plasma on Rabbit Tendon Stem Cells In Vitro

BACKGROUND

Platelet-rich plasma (PRP) is now widely used as a promising treatment for patients with tendinopathy. However, the efficacy of PRP treatment for tendinopathy is controversial mainly because of inconsistent results from human clinical trials and particularly because the concentration and effect of leukocytes in PRP remain largely unknown.

HYPOTHESIS

Leukocyte-rich PRP (L-PRP) inhibits growth factor release, decreases proliferation, and induces nontenocyte differentiation of tendon stem cells (TSCs); increases catabolic cytokine concentrations; and causes inflammation and apoptosis. Thus, L-PRP has a detrimental effect on tendon stem/progenitor cells, which impairs injured tendon healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Pure PRP (P-PRP) and L-PRP were prepared from the same individual rabbit blood, and platelet numbers in each PRP product were adjusted to reach the same level. The leukocyte level in L-PRP was 4 and 8 times higher than those in whole blood and P-PRP, respectively. The growth factors in both P-PRP and L-PRP were measured by enzyme-linked immunosorbent assay kits. The morphology, stemness, proliferation, and differentiation of TSCs grown in L-PRP and P-PRP were examined by microscopy, immunocytochemistry, population doubling time, quantitative real-time polymerase chain reaction, and histological analysis.

RESULTS

L-PRP produced lower levels of growth factors, such as vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), transforming growth factor (TGF)-β1, and platelet-derived growth factor (PDGF), than did P-PRP. TSC proliferation was significantly decreased in L-PRP in a concentration-dependent manner. Furthermore, TSCs cultured in P-PRP produced more collagen and formed tendon-like tissue; however, TSCs grown in L-PRP differentiated into nontenocytes and produced more inflammatory factors such as membrane-associated prostaglandin synthase (mPGES) and interleukin (IL)-1β. Moreover, L-PRP was associated with increased apoptosis.

CONCLUSION

L-PRP has harmful effects on TSCs.

CLINICAL RELEVANCE

This study revealed the direct effects of different compositions of PRP on TSCs and provided basic scientific data to help understand the cellular and molecular mechanisms of the efficacy of PRP treatment in clinical use.

Mutational Evidence for the Critical Role of CBF Transcription Factors in Cold Acclimation in Arabidopsis

The three tandemly arranged CBF genes, CBF1, CBF2, and CBF3, are involved in cold acclimation. Due to the lack of stable loss-of-function Arabidopsis (Arabidopsis thaliana) mutants deficient in all three CBF genes, it is still unclear whether the CBF genes are essential for freezing tolerance and whether they may have other functions besides cold acclimation. In this study, we used the CRISPR/Cas9 system to generate cbf single, double, and triple mutants. Compared to the wild type, the cbf triple mutants are extremely sensitive to freezing after cold acclimation, demonstrating that the three CBF genes are essential for cold acclimation. Our results show that the three CBF genes also contribute to basal freezing tolerance. Unexpectedly, we found that the cbf triple mutants are defective in seedling development and salt stress tolerance. Transcript profiling revealed that the CBF genes regulate 414 cold-responsive (COR) genes, of which 346 are CBF-activated genes and 68 are CBF-repressed genes. The analysis suggested that CBF proteins are extensively involved in the regulation of carbohydrate and lipid metabolism, cell wall modification, and gene transcription. Interestingly, like the triple mutants, cbf2 cbf3 double mutants are more sensitive to freezing after cold acclimation compared to the wild type, but cbf1 cbf3 double mutants are more resistant, suggesting that CBF2 is more important than CBF1 and CBF3 in cold acclimation-dependent freezing tolerance. Our results not only demonstrate that the three CBF genes together are required for cold acclimation and freezing tolerance, but also reveal that they are important for salt tolerance and seedling development.

A Palladium-Binding Deltarhodopsin for Light-Activated Conversion of Protonic to Electronic Currents

Fusion of a palladium-binding peptide to an archaeal rhodopsin promotes intimate integration of the lipid-embedded membrane protein with a palladium hydride protonic contact. Devices fabricated with the palladium-binding deltarhodopsin enable light-activated conversion of protonic currents to electronic currents with on/off responses complete in seconds and a nearly tenfold increase in electrical signal relative to those made with the wild-type protein.

Metabolic regulation of triacylglycerol accumulation in the green algae: identification of potential targets for engineering to improve oil yield

The great need for more sustainable alternatives to fossil fuels has increased our research interests in algal biofuels. Microalgal cells, characterized by high photosynthetic efficiency and rapid cell division, are an excellent source of neutral lipids as potential fuel stocks. Various stress factors, especially nutrient-starvation conditions, induce an increased formation of lipid bodies filled with triacylglycerol in these cells. Here we review our knowledge base on glycerolipid synthesis in the green algae with an emphasis on recent studies on carbon flux, redistribution of lipids under nutrient-limiting conditions and its regulation. We discuss the contributions and limitations of classical and novel approaches used to elucidate the algal triacylglycerol biosynthetic pathway and its regulatory network in green algae. Also discussed are gaps in knowledge and suggestions for much needed research both on the biology of triacylglycerol accumulation and possible avenues to engineer improved algal strains.

Disrupting P-glycoprotein function in clinical settings: what can we learn from the fundamental aspects of this transporter?

P-glycoprotein is one of the most well-studied drug transporters, significant for its role in cancer multiple drug resistance. However, using P-gp inhibitors with the aim of enhancing the therapeutic efficacy of anti-cancer drugs has led to disappointing outcomes. Furthermore, several lead compounds suggested by in vitro and pre-clinical studies have shown variable pharmacokinetics and therapeutic efficacies when applied in the clinical setting. This review will highlight the need to revisit a sound approach to better design and apply P-gp inhibitors in light of safety and efficacy. Challenges confronting the issue hinge upon myriad studies that do not necessarily represent the heterogeneous target population of this therapeutic approach. The application of P-gp modulators has also been complicated by the promiscuous substrate-binding behaviour of P-gp, as well as toxicities related to its intrinsic presence in healthy tissue. This review capitalizes on information spanning genetics, energetics, and pharmacology, bringing to light some fundamental aspects that ought to be reconsidered in order to improve upon and design the next generation of P-gp inhibitors.

Plant powder teabags: a novel and practical approach to resolve culturability and diversity of rhizobacteria

We have developed teabags packed with dehydrated plant powders, without any supplements, for preparation of plant infusions necessary to develop media for culturing rhizobacteria. These bacteria are efficiently cultivated on such plant teabag culture media, with better progressive in situ recoverability compared to standard chemically synthetic culture media. Combining various plant-based culture media and incubation conditions enabled us to resolve unique denaturing gradient gel electrophoresis (DGGE) bands that were not resolved by tested standard culture media. Based on polymerase chain reaction PCR-DGGE of 16S rDNA fingerprints and sequencing, the plant teabag culture media supported higher diversity and significant increases in the richness of endo-rhizobacteria, namely Gammaproteobacteria (Enterobacteriaceae) and predominantly Alphaproteobacteria (Rhizobiaceae). This culminated in greater retrieval of the rhizobacteria taxa associated with the plant roots. We conclude that the plant teabag culture medium by itself, without any nutritional supplements, is sufficient and efficient for recovering and mirroring the complex and diverse communities of rhizobacteria. Our message to fellow microbial ecologists is: simply dehydrate your plant canopy, teabag it and soak it to prepare your culture media, with no need for any additional supplementary nutrients.

Carbon nanotubes play an important role in the spatial arrangement of calcium deposits in hydrogels for bone regeneration

Age related bone diseases such as osteoporosis are considered among the main causes of reduced bone mechanical stability and bone fractures. In order to restore both biological and mechanical function of diseased/fractured bones, novel bioactive scaffolds that mimic the bone structure are constantly under development in tissue engineering applications. Among the possible candidates, chitosan-based thermosensitive hydrogel scaffolds represent ideal systems due to their biocompatibility, biodegradability, enhanced antibacterial properties, promotion of osteoblast formation and ease of injection, which makes them suitable for less invasive surgical procedures. As a main drawback, these chitosan systems present poor mechanical performance that could not support load-bearing applications. In order to produce more mechanically-competent biomaterials, the combined addition of hydroxyapatite and carbon nanotubes (CNTs) is proposed in this study. Specifically, the aim of this work is to develop thermosensitive chitosan hydrogels containing stabilised single-walled and multi-walled CNTs, where their effect on the mechanical/physiochemical properties, calcium deposition patterns and ability to provide a platform for the controlled release of protein drugs was investigated. It was found that the addition of CNTs had a significant effect on the sol-gel transition time and significantly increased the resistance to compression for the hydrogels. Moreover, in vitro calcification studies revealed that CNTs played a major role in the spatial arrangements of newly formed calcium deposits in the composite materials studied, suggesting that they may have a role in the way the repair of fragile and/or fractured bones occurs in vivo.

Overcoming Instability of Antibody-Nanomaterial Conjugates: Next Generation Targeted Nanomedicines Using Bispecific Antibodies

Targeted nanomaterials promise improved therapeutic efficacy, however their application in nanomedicine is limited due to complexities associated with protein conjugations to synthetic nanocarriers. A facile method to generate actively targeted nanomaterials is developed and exemplified using polyethylene glycol (PEG)-functional nanostructures coupled to a bispecific antibody (BsAb) with dual specificity for methoxy PEG (mPEG) epitopes and cancer targets such as epidermal growth factor receptor (EGFR). The EGFR-mPEG BsAb binds with high affinity to recombinant EGFR (KD : 1 × 10(-9) m) and hyperbranched polymer (HBP) consisting of mPEG (KD : 10 × 10(-9) m) and demonstrates higher avidity for HBP compared to linear mPEG. The binding of BsAb-HBP bioconjugate to EGFR on MDA-MB-468 cancer cells is investigated in vitro using a fluorescently labeled polymer, and in in vivo xenograft models by small animal optical imaging. The antibody-targeted nanostructures show improved accumulation in tumor cells compared to non-targeted nanomaterials. This demonstrates a facile approach for tuning targeting ligand density on nanomaterials, by modulating surface functionality. Antibody fragments are tethered to the nanomaterial through simple mixing prior to administration to animals, overcoming the extensive procedures encountered for developing targeted nanomedicines.

Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases

The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography-mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2-7) and temperatures (5-55 °C) without the need for Cu(2+). Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice.

In Vitro Testing of Biomaterials for Neural Repair: Focus on Cellular Systems and High-Content Analysis

Biomimetic materials are designed to stimulate specific cellular responses at the molecular level. To improve the soundness of in vitro testing of the biological impact of new materials, appropriate cell systems and technologies must be standardized also taking regulatory issues into consideration. In this study, the biological and molecular effects of different scaffolds on three neural systems, that is, the neural cell line SH-SY5Y, primary cortical neurons, and neural stem cells, were compared. The effect of poly(L-lactic acid) scaffolds having different surface geometry (conventional two-dimensional seeding flat surface, random or aligned fibers as semi3D structure) and chemical functionalization (laminin or ECM extract) were studied. The endpoints were defined for efficacy (i.e., neural differentiation and neurite elongation) and for safety (i.e., cell death/survival) using high-content analysis. It is demonstrated that (i) the definition of the biological properties of biomaterials is profoundly influenced by the test system used; (ii) the definition of the in vitro safety profile of biomaterials for neural repair is also influenced by the test system; (iii) cell-based high-content screening may well be successfully used to characterize both the efficacy and safety of novel biomaterials, thus speeding up and improving the soundness of this critical step in material science having medical applications.

Using simple models to describe the kinetics of growth, glucose consumption, and monoclonal antibody formation in naive and infliximab producer CHO cells

Despite their practical and commercial relevance, there are few reports on the kinetics of growth and production of Chinese hamster ovary (CHO) cells-the most frequently used host for the industrial production of therapeutic proteins. We characterize the kinetics of cell growth, substrate consumption, and product formation in naive and monoclonal antibody (mAb) producing recombinant CHO cells. Culture experiments were performed in 125 mL shake flasks on commercial culture medium (CD Opti CHO™ Invitrogen, Carlsbad, CA, USA) diluted to different glucose concentrations (1.2-4.8 g/L). The time evolution of cell, glucose, lactic acid concentration and monoclonal antibody concentrations was monitored on a daily basis for mAb-producing cultures and their naive counterparts. The time series were differentiated to calculate the corresponding kinetic rates (rx = d[X]/dt; rs = d[S]/dt; rp = d[mAb]/dt). Results showed that these cell lines could be modeled by Monod-like kinetics if a threshold substrate concentration value of [S]t = 0.58 g/L (for recombinant cells) and [S]t = 0.96 g/L (for naïve cells), below which growth is not observed, was considered. A set of values for μmax, and Ks was determined for naive and recombinant cell cultures cultured at 33 and 37 °C. The yield coefficient (Yx/s) was observed to be a function of substrate concentration, with values in the range of 0.27-1.08 × 10(7) cell/mL and 0.72-2.79 × 10(6) cells/mL for naive and recombinant cultures, respectively. The kinetics of mAb production can be described by a Luedeking-Piret model (d[mAb]/dt = αd[X]/dt + β[X]) with values of α = 7.65 × 10(-7) µg/cell and β = 7.68 × 10(-8) µg/cell/h for cultures conducted in batch-agitated flasks and batch and instrumented bioreactors operated in batch and fed-batch mode.

Template-based syntheses for shape controlled nanostructures

A variety of nanostructured materials are produced through template-based synthesis methods, including zero-dimensional, one-dimensional, and two-dimensional structures. These span different forms such as nanoparticles, nanowires, nanotubes, nanoflakes, and nanosheets. Many physical characteristics of these materials such as the shape and size can be finely controlled through template selection and as a result, their properties as well. Reviewed here are several examples of these nanomaterials, with emphasis specifically on the templates and synthesis routes used to produce the final nanostructures. In the first section, the templates have been discussed while in the second section, their corresponding synthesis methods have been briefly reviewed, and lastly in the third section, applications of the materials themselves are highlighted. Some examples of the templates frequently encountered are organic structure directing agents, surfactants, polymers, carbon frameworks, colloidal sol-gels, inorganic frameworks, and nanoporous membranes. Synthesis methods that adopt these templates include emulsion-based routes and template-filling approaches, such as self-assembly, electrodeposition, electroless deposition, vapor deposition, and other methods including layer-by-layer and lithography. Template-based synthesized nanomaterials are frequently encountered in select fields such as solar energy, thermoelectric materials, catalysis, biomedical applications, and magnetowetting of surfaces.

Synthesis of siderophores by plant-associated metallotolerant bacteria under exposure to Cd(2.)

Rhizosphere and endophytic bacteria are well known producers of siderophores, organic compounds that chelate ferric iron (Fe(3+)), and therefore play an important role in plant growth promotion in metalliferous areas, thereby improving bioremediation processes. However, in addition to their primary function in iron mobilization, siderophores also have the capacity to chelate other heavy metals, such as Al(3+), Zn(2+), Cu(2+), Pb(2+) and Cd(2+), that can affect homeostasis and the heavy metal tolerance of microorganisms. The main goal of our study was to select the most efficient siderophore-producing bacterial strains isolated from the roots (endophytes) and rhizosphere of Betula pendula L. and Alnus glutinosa L. growing at two heavy metal contaminated sites in southern Poland. Siderophore biosynthesis of these strains in the presence of increasing concentrations of Cd(2+) (0, 0.5, 1, 2 and 3 mM) under iron-deficiency conditions was analysed using spectrophotometric chemical tests for hydroxamates, catecholates and phenolates, as well as the separation of bacterial siderophores by HPLC and characterization of their structure by UHPLC-QTOF/MS. We proved that (i) siderophore-producing bacterial strains seems to be more abundant in the rhizosphere (47%) than in root endophytes (18%); (ii) the strains most effective at siderophore synthesis belonged to the genus Streptomyces and were able to secrete three types of siderophores under Cd(2+) stress: hydroxamates, catecholates and phenolates; (iii) in general, the addition of Cd(2+) enhanced siderophore synthesis, particularly ferrioxamine B synthesis, which may indicate that siderophores play a significant role in tolerance to Cd(2+) in Streptomyces sp.

Overexpression of OsOSM1 Enhances Resistance to Rice Sheath Blight

Sheath blight (SB), caused by Rhizoctonia solani, is one of the most destructive rice diseases worldwide. It has been difficult to generate SB-resistant varieties through conventional breeding because of the quantitative nature of rice resistance to SB. In this study, we found that overexpression of the OsOSM1 gene, encoding an osmotin protein belonging to the pathogenesis-related protein 5 family, is able to improve rice resistance to SB in field tests. Although there are two osmotin genes in rice, OsOSM1 is the one mainly expressed in leaf sheath at the booting stage, coinciding with the critical stage of SB development in the field. In addition, OsOSM1 expression is strongly induced by R. solani in SB-resistant rice variety YSBR1 but not in susceptible varieties, suggesting its involvement in SB resistance. Overexpression of OsOSM1 (OsOSM1ox) in susceptible variety Xudao 3 significantly increases resistance to SB in transgenic rice. The OsOSM1 mRNA levels in different transgenic lines are found to be positively correlated with their SB resistance levels. Intriguingly, although extremely high levels of OsOSM1 were detrimental to rice development, appropriately elevated levels of OsSOM1 were obtained that enhanced rice SB resistance without affecting rice development or grain yield. The OsSOM1 protein is localized on plasma membrane. OsOSM1 is upregulated by jasmonic acid (JA); furthermore, JA-responsive marker genes are induced in OsOSM1ox lines. These results suggest that the activation of JA signaling pathway may account for the increased resistance in transgenic OsOSM1ox lines. Taken together, our results demonstrate that OsOSM1 plays an important role in defense against rice SB disease and provides a new target for engineering resistance to SB.

Improved aqueous extraction of microalgal lipid by combined enzymatic and thermal lysis from wet biomass of Nannochloropsis oceanica

High moisture content in wet algal biomass hinders effective performance of current lipid extraction methods. An improved aqueous extraction method combing thermal and enzymatic lysis was proposed and performed in algal slurry of Nannochloropsis oceanica (96.0% moisture) in this study. In general, cell-wall of N. oceanica was disrupted via thermal lysis and enzymatic lysis and lipid extraction was performed using aqueous surfactant solution. At the optimal conditions, high extraction efficiencies for both lipid (88.3%) and protein (62.4%) were obtained, which were significantly higher than those of traditional hexane extraction and other methods for wet algal biomass. Furthermore, an excessive extraction of polar lipid was found for wet biomass compared with dry biomass. The advantage of this method is to efficiently extract lipids from high moisture content algal biomass and avoid using organic solvent, indicating immense potential for commercial microalgae-based biofuel production.

Surface Immobilization of Human Arginase-1 with an Engineered Ice Nucleation Protein Display System in E. coli

Ice nucleation protein (INP) is frequently used as a surface anchor for protein display in gram-negative bacteria. Here, MalE and TorA signal peptides, and three charged polypeptides, 6×Lys, 6×Glu and 6×Asp, were anchored to the N-terminus of truncated INP (InaK-N) to improve its surface display efficiency for human Arginase1 (ARG1). Our results indicated that the TorA signal peptide increased the surface translocation of non-protein fused InaK-N and human ARG1 fused InaK-N (InaK-N/ARG1) by 80.7% and 122.4%, respectively. Comparably, the MalE signal peptide decreased the display efficiencies of both the non-protein fused InaK-N and InaK-N/ARG1. Our results also suggested that the 6×Lys polypeptide significantly increased the surface display efficiency of K6-InaK-N/ARG1 by almost 2-fold, while also practically abolishing the surface translocation of non-protein fused InaK-N, indicating the interesting roles of charged polypeptides in bacteria surface display systems. Cell surface-immobilized K6-InaK-N/ARG1 presented an arginase activity of 10.7 U/OD600 under the optimized conditions of 40°C, pH 10.0 and 1 mM Mn2+, which could convert more than 95% of L-Arginine (L-Arg) to L-Ornithine (L-Orn) in 16 hours. The engineered InaK-Ns expanded the INP surface display system, which aided in the surface immobilization of human ARG1 in E. coli cells.

Enhanced Biological Functions of Human Mesenchymal Stem-Cell Aggregates Incorporating E-Cadherin-Modified PLGA Microparticles

Mesenchymal stem cells (MSCs) have emerged as a promising source of multipotent cells for various cell-based therapies due to their unique properties, and formation of 3D MSC aggregates has been explored as a potential strategy to enhance therapeutic efficacy. In this study, poly(lactic-co-glycolic acid) (PLGA) microparticles modified with human E-cadherin fusion protein (hE-cad-PLGA microparticles) have been fabricated and integrated with human MSCs to form 3D cell aggregates. The results show that, compared with the plain PLGA, the hE-cad-PLGA microparticles distribute within the aggregates more evenly and further result in a more significant improvement of cellular proliferation and secretion of a series of bioactive factors due to the synergistic effects from the bioactive E-cadherin fragments and the PLGA microparticles. Meanwhile, the hE-cad-PLGA microparticles incorporated in the aggregates upregulate the phosphorylation of epidermal growth factor receptors and activate the AKT and ERK1/2 signaling pathways in the MSCs. Additionally, the E-cadherin/β-catenin cellular membrane complex in the MSCs is markedly stimulated by the hE-cad-PLGA microparticles. Therefore, engineering 3D cell aggregates with hE-cad-PLGA microparticles can be a promising method for ex vivo multipotent stem-cell expansion with enhanced biological functions and may offer a novel route to expand multipotent stem-cell-based clinical applications.

First-generation HapMap in Cajanus spp. reveals untapped variations in parental lines of mapping populations

Whole genome re-sequencing (WGRS) was conducted on a panel of 20 Cajanus spp. accessions (crossing parentals of recombinant inbred lines, introgression lines, multiparent advanced generation intercross and nested association mapping population) comprising of two wild species and 18 cultivated species accessions. A total of 791.77 million paired-end reads were generated with an effective mapping depth of ~12X per accession. Analysis of WGRS data provided 5 465 676 genome-wide variations including 4 686 422 SNPs and 779 254 InDels across the accessions. Large structural variations in the form of copy number variations (2598) and presence and absence variations (970) were also identified. Additionally, 2 630 904 accession-specific variations comprising of 2 278 571 SNPs (86.6%), 166 243 deletions (6.3%) and 186 090 insertions (7.1%) were also reported. Identified polymorphic sites in this study provide the first-generation HapMap in Cajanus spp. which will be useful in mapping the genomic regions responsible for important traits.

Engineering of bacterial exotoxins for highly efficient and receptor-specific intracellular delivery of diverse cargos

The intracellular delivery of proteins with high efficiency in a receptor-specific manner is of great significance in molecular medicine and biotechnology, but remains a challenge. Herein, we present the development of a highly efficient and receptor-specific delivery platform for protein cargos by combining the receptor binding domain of Escherichia coli Shiga-like toxin and the translocation domain of Pseudomonas aeruginosa exotoxin A. We demonstrated the utility and efficiency of the delivery platform by showing a cytosolic delivery of diverse proteins both in vitro and in vivo in a receptor-specific manner. In particular, the delivery system was shown to be effective for targeting an intracellular protein and consequently suppressing the tumor growth in xenograft mice. The present platform can be widely used for intracellular delivery of diverse functional macromolecules with high efficiency in a receptor-specific manner. Biotechnol. Bioeng. 2016;113: 1639-1646. © 2016 Wiley Periodicals, Inc.