The surface and mechanical properties of the so developed conductive scaffolds have been investigated being these features crucial for their use in osteoinduction studies. These preliminary results pave the way to further studies on the combined effects of electrical and topographical cues in bone tissue regeneration applications. Resume : The electrochemical activation of redox substances may be a way to control the chemical environment through the regulation of pH .
Previously, water electrolysis , the reduction of redox molecules in solution , functionalized electrodes  and nanoparticle composites have been reported  as methods to change the pH. A reliable and efficient method that can allow pH control, with an ease of fabrication for microfluidic devices has not yet been developed.
We investigated the polymerizations of 4ATP on Au substrates using electrochemical measurements and surface characterization methods. Electrochemical and ultraviolet polymerization were probed under different conditions of pH, power and speed-rates, because theoretical studies claim they have different polymerization reactions  that could lead to different reversibility efficiencies.
The surface coverage and the reversibility of redox reactions of the polymerized molecules for both techniques were analysed and compared. The pH change as a function of these reversible processes was modelled. Analytical Chemistry , 83 11 , Analytical Chemistry, , 80 4 , Egeland, Frank Marken, and Edwin M. Analytical Chemistry, , 74, 7 , Journal of electroanalytical Chemistry and Interfacial Electrochemistry, , , Journal of the American Chemical Society, , 6 , The Journal of Physical Chemistry, , 46 , Resume : Thin films from conjugated small molecule semiconductors are important building blocks for organic electronics, but can also serve as active or passive templates for biological applications.
Functionalization can control their electrical and optical properties, and even change the thin film morphology . Cyano-functionalization is of special interest due to the asymmetric charge distribution. Oriented organic nanofibers form after vacuum deposition on muscovite mica.
Thin-film phases are identified by X-ray diffraction. Two types of fibers are observed, growing along distinct substrate directions. Their optical properties such as the polarization of the emitted fluorescence after UV-excitation , their morphology, and their electric surface potential differ, reflecting different polymorphs. In ambient, the morphology of the fiber-films is altered over time by Ostwald-ripening . This behavior is compared to their stability in a physiological electrolyte.
Schiek, F. Balzer, K. Al-Shamery, A.
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Rubahn, Soft Matter , 4: Balzer, M. Balzer, Ch. Rubahn, A. Parisi, R. Resel, M.
Schiek, J. C , Resume : An intelligent surface, which can control cell adhesion and deadhesion by changing temperature, has been proposed by our laboratory. In order to quantitatively evaluate cell detachment process from hydrophilic PIPAAm surface, a microfluidic device was constructed on the surface, referring to a parallel plate flow chamber PPFC. A laminar flow, which could generate shear force within the chamber, was applied to cells in flow chamber, resulting in cell detachment. A cell transformation rate constant Ct and an intrinsic cell detachment rate constant k0 were obtained through studying the effect of shear stress on cell detachment, referring to a peeling model.
NanoBioTechnology : BioInspired Devices and Materials of the Future
This approach provided a basis for the theoretical analysis of interaction between cells and PIPAAm surface. Cells applied with a high shear stress were removed for the substrate more quickly than those applied with a low shear stress. Moreover, Ct, and k0 were obtained through analyzing the kinetics of cell detachment. Resume : The widespread use of antibiotics and biocides has given rise to the development of multidrug-resistant bacteria also called super bugs.
The propagation of super bugs has become one of the most serious health threats that humans face today.
Nanobiotechnology: BioInspired Devices and Materials of the future (A Review)
Conversely, nature has evolved a range of antibacterial approaches that do not cause bacteria resistance. In particular, in nature we find persistent antibacterial surfaces such as the cicada wing having a bactericidal effect that depends solely on its surface topography .
In this work, polymer nanoimprinting topographies inspired on the cicada wing comprising arrays of well defined nanocones with a high aspect ratio HAR have been tested. To assess the bactericidal effect, live and dead bacteria cells attached to the substrates were stained differentially and counted. SEM images revealed that cicada nanocones induced a mechanical rupture and release of the cytoplasm content of some of the bacteria few hours after their attachment.
In contrast, the surfaces were biocompatible allowing the spread and growth of keratinocytes. ACS Appl. Mater Interfaces , 7, 2 Bhadra et al. Sci Rep , 5, Resume : Biodegradable particulate system is heavily researched as drug carrier to meet the treatment requirements with controllable dosage and minimized toxicity. Rapamycin is widely used in cancer treatment and post-transplantation rejection suppression. However, higher than required amount of rapamycin was often administered, which leads to negative side effect and high cytotoxicity.
This presentation reports synthesis of multiple microparticles formulation for long-term release of rapamycin at its minimum dosage. The longest release duration achieved was 30 days, while altering specific particulate parameters gave rise to different rapamycin release profiles. Additionally, this water-sensitive drug was protected from rapid degradation after encapsulated inside microparticle.
Furthermore, the bioactivity of the released rapamycin was assessed using cancer cell MCF-7 cell and human lymphocyte cell Jurkat cell. Inhibition effect on MCF-7 proliferation was observed and the degree of inhibition at selected time points was in good agreement with the in vitro release profile. The antiproliferation effect of top two rapmycin microparticles in terms of cumulative release was further evaluated. Both formulations were shown to suppress jurkat cell growth up to 20 days. Not only the duration was longer than free rapamycin drug, but the inhibition efficacy was also increased two times.
These results not only demonstrate the ability of our formulations to tune delivery of hydrophobic drug, rapamycin, but also indicate the preservation effect of particulate carrier of degradable drug in vitro. Resume : The use of conducting polymers as materials for bioelectronics is a rapidly-growing research field. Moreover, since the physical and chemical properties of conducting polymers can be modified in response to electrical stimuli, these materials can be used as active substrates for cell growth.
Recently, conducting polymers were proved to influence cell behavior, in terms of cell adhesion and growth, by a change in their oxidation state.
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The cell-substrate interaction involves many different parameters, both physical surface roughness, surface energy , chemical pH, oxidation state and biological extra-cellular matrix formation, protein conformation , but the way these parameters are related to each other and to cell behavior is still not clear. Gaining a better understanding of the processes that control cell adhesion is crucial in order to use conducting polymers as a new tool in basic research, medical diagnostics, and tissue engineering.
We employed two different techniques, spin-coating and electro-polymerization, to deposit thin films of a bio-compatible conducting polymer widely used in organic electronics, poly 3,4-ethylene dioxythiophene doped with poly styrenesulfonate PEDOT:PSS. These techniques impart quite different physical and chemical properties to the films, namely surface roughness, electrical conductivity, and electrochemical properties.
The oxidation state of the polymer films was subsequently modified by applying a continuous bias in electrolyte solution for one hour.
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We characterized the effects of these deposition methods by atomic force microscopy, optical absorption, wettability, electrical and electrochemical analyses as a function of the oxidation state of PEDOT:PSS. The time-stability of the induced redox state was also assessed in different aqueous media, as distilled water, phosphate buffer and cell culture medium.
Cell adhesion and proliferation were monitored on line for a time interval up to 72h three days by automatized optical microscopy. Marzocchi, I. Gualandi, M. Calienni, I. Zironi, E. Scavetta, G.