Bacterial nanocellulose production: Improvement in productivity and properties via a sustainable medium.

High production cost is a significant barrier to commercial bacterial nanocellulose (BNC) production. This study addresses this issue using a low-cost molasses and cheese whey medium via Gluconacetobacter hansenii. The one-factor-at-a-time method investigated the effect of critical factors on BNC production, including total sugar and total protein concentrations (g/L), initial pH, and additives such as ethanol and acetic acid (%(v/v)).

Dark-Field Microscopic Study of Cellular Uptake of Carbon Nanodots: Nuclear Penetrability.

Carbon nanodots are fascinating candidates for the field of biomedicine, in applications such as bioimaging and drug delivery. However, the nuclear penetrability and process are rarely studied and lack understanding, which limits their applications for drug carriers, single-molecule detection and live cell imaging. In this study, we attempt to examine the uptake of CNDs in cells with a focus on the potential nuclear penetrability using enhanced dark-field microscopy (EDFM) associated with hyperspectral imaging (HSI) to quantitatively determine the light scattering signals of CNDs in the cells.

Tuning Microbial Activity via Programmatic Alteration of Cell/Substrate Interfaces.

A wide portfolio of advanced programmable materials and structures has been developed for biological applications in the last two decades. Particularly, due to their unique properties, semiconducting materials have been utilized in areas of biocomputing, implantable electronics, and healthcare. As a new concept of such programmable material design, biointerfaces based on inorganic semiconducting materials as substrates introduce unconventional paths for bioinformatics and biosensing.

Cell Rupture and Morphogenesis Control of the Dimorphic Yeast by Nanostructured Surfaces.

Nanostructured surfaces control microbial biofilm formation by killing mechanically via surface architecture. However, the interactions between nanostructured surfaces (NSS) and cellular fungi have not been thoroughly investigated and the application of NSS as a means of controlling fungal biofilms is uncertain. Cellular yeast such as are structurally and biologically distinct from prokaryotic microbes and therefore are predicted to react differently to nanostructured surfaces.

Characterization of Hydrothermal Deposition of Copper Oxide Nanoleaves on Never-Dried Bacterial Cellulose.

Bacterial cellulose (BC) has attracted a great deal of interest due to its green synthesis and biocompatibility. The nanoscale dimension of BC nanofibers generates an enormous surface area that enhances interactions with water and soluble components within aqueous solution. Recent work has demonstrated that BC is a versatile platform for the formation of metal/metal oxide nanocomposites.

Behavior of with Variable Surface Morphology Changes on Charged Semiconductor Interfaces.

Bacterial behavior is often controlled by structural and composition elements of their cell wall. Using genetic mutant strains that change specific aspects of their surface structure, we modified bacterial behavior in response to semiconductor surfaces. We monitored the adhesion, membrane potential, and catalase activity of the Gram-negative bacterium () that were mutant for genes encoding components of their surface architecture, specifically flagella, fimbriae, curli, and components of the lipopolysaccharide membrane, while on gallium nitride (GaN) surfaces with different surface potentials.

Variably doped nanostructured gallium nitride surfaces can serve as biointerfaces for neurotypic PC12 cells and alter their behavior.

Neurotypic PC12 cells behavior was studied on nanostructured GaN and rationalized with respect to surface charge, doping level, and chemical functionalization. The semiconductor analysis included atomic force microscopy, Kelvin probe force microscopy, and X-ray photoelectron spectroscopy. The semiconductor surfaces were then evaluated as biointerfaces, and the cell behavior was quantified based on cell viability, reactive oxygen species production, as well as time dependent intracellular Ca concentration, [Ca], a known cell-signaling molecule.

Nanosphere Lithography of Chitin and Chitosan with Colloidal and Self-Masking Patterning.

Complex surface topographies control, define, and determine the properties of insect cuticles. In some cases, these nanostructured materials are a direct extension of chitin-based cuticles. The cellular mechanisms that generate these elaborate chitin-based structures are unknown, and involve complicated cellular and biochemical "bottom-up" processes.

Characterization of Pseudomonas aeruginosa Films on Different Inorganic Surfaces before and after UV Light Exposure.

The changes of the surface properties of Au, GaN, and SiO after UV light irradiation were used to actively influence the process of formation of Pseudomonas aeruginosa films. The interfacial properties of the substrates were characterized by X-ray photoelectron spectroscopy and atomic force microscopy. The changes in the P.

Noninvasive Stimulation of Neurotypic Cells Using Persistent Photoconductivity of Gallium Nitride.

The persistent photoconductivity (PPC) of the n-type Ga-polar GaN was used to stimulate PC12 cells noninvasively. Analysis of the III-V semiconductor material by atomic force microscopy, Kelvin probe force microscopy, photoconductivity, and X-ray photoelectron spectroscopy quantified bulk and surface charge, as well as chemical composition before and after exposure to UV light and cell culture media. The semiconductor surface was made photoconductive by illumination with UV light and experienced PPC, which was utilized to stimulate PC12 cells in vitro.

Bioelectronics communication: encoding yeast regulatory responses using nanostructured gallium nitride thin films.

Baker's yeast, S. cerevisiae, is a model organism that is used in synthetic biology. The work demonstrates how GaN nanostructured thin films can encode physiological responses in S.

Alternative SiO Surface Direct MDCK Epithelial Behavior.

The mechanical interactions of cells are mediated through adhesive interactions. In this study, we examined the growth, cellular behavior, and adhesion of MDCK epithelial cells on three different SiO substrates: amorphous glass coverslips and the silicon oxide layers that grow on ⟨111⟩ and ⟨100⟩ wafers. While compositionally all three substrates are almost similar, differences in surface energy result in dramatic differences in epithelial cell morphology, cell-cell adhesion, cell-substrate adhesion, actin organization, and extracellular matrix (ECM) protein expression.

Peristalsis in the junction region of the Drosophila larval midgut is modulated by DH31 expressing enteroendocrine cells.

Background: The underlying cellular and molecular mechanisms that coordinate the physiological processes in digestion are complex, cryptic, and involve the integration of multiple cellular and organ systems. In all intestines, peristaltic action of the gut moves food through the various stages of digestion from the anterior end towards the posterior, with the rate of flow dependent on signals, both intrinsic and extrinsic to the gut itself.

Results: We have identified an enteroendocrine cell type that regulates gut motility in the Drosophila melanogaster larval midgut.

Modeling early Epstein-Barr virus infection in Drosophila melanogaster: the BZLF1 protein.

Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis and is associated with several forms of cancer, including lymphomas and nasopharyngeal carcinoma. The EBV immediate-early protein BZLF1 functions as a transcriptional activator of EBV early gene expression and is essential for the viral transition between latent and lytic replication. In addition to its role in the EBV life cycle, BZLF1 (Z) also has profound effects upon the host cellular environment, including disruption of cell cycle regulation, signal transduction pathways, and transcription.

Epstein-Barr virus immediate-early proteins BZLF1 and BRLF1 alter mitochondrial morphology during lytic replication.

Epstein-Barr virus (EBV) is a human DNA virus that is responsible for the syndrome infectious mononucleosis, and is associated with several forms of cancer. During both lytic and latent viral infection, viral proteins manipulate the host's cellular components to aid in viral replication and maintenance. Here, it is demonstrated that induction of EBV lytic replication results in a dramatic reorganization of mitochondria accompanied by a significant alteration of mitochondrial membrane potential and a rapid and transient increase in the microtubular cytoskeleton.

Three new Drosophila markers of intracellular membranes.

The need for cellular markers that permit a quick and accurate evaluation of a protein's subcellular localization has increased with the surge of new data generated by the Drosophila genome project. In this report, we present three ubiquitously expressed Drosophila transgenes that expressed a green fluorescent protein variant (enhanced yellow fluorescent protein) that has been targeted to different intracellular membrane targets: the Golgi apparatus, mitochondria, and endoplasmic reticulum. These markers serve as an internal standard for characterizing a protein's subcellular localization or as a means of tracking the dynamics of intracellular organelles during normal or abnormal cellular or developmental processes.