Carbon Nanomaterials Embedded in Conductive Polymers: A State of the Art

Carbon nanomaterials are at the forefront of the newest technologies of the third millennium, and together with conductive polymers, represent a vast area of indispensable knowledge for developing the devices of tomorrow. This review focusses on the most recent advances in the field of conductive nanotechnology, which combines the properties of carbon nanomaterials with conjugated polymers. Hybrid materials resulting from the embedding of carbon nanotubes, carbon dots and graphene derivatives are taken into consideration and fully explored, with discussion of the most recent literature. An introduction into the three most widely used conductive polymers and a final section about the most recent biological results obtained using carbon nanotube hybrids will complete this overview of these innovative and beyond belief materials.The European Union is acknowledged for funding this research through Horizon 2020 MSCA-IF-2018 No 838171 (TEXTHIOL). IMDEA Nanociencia acknowledges support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grant SEV- 2016-0686). European Regional Development fund Project “MSCAfellow4 @ MUNI” supported by MEYS CR (No. CZ.02.2.69/0.0/0.0/20_079/0017045) is acknowledged. N.A. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 753293, acronym NanoBEAT

Reductive nanometric patterning of graphene oxide paper using electron beam lithography

Electron beam lithography (EBL) was used for preparing nanostructured reduced patterns on the GO paper surface, while preserving its mechanical resistance and flexibility. Different EBL parameters, like dose and time of exposure for patterning were tested. SEM analysis showed the consequent increase of contrast of the reduced stripes on the patterned regions due to the increase of electron beam doses. Moreover, surface potential microscopy experiments also exhibited a clear contrast between the patterned and non-patterned regions. Structural analysis of the patterned paper through X-ray diffraction and nanoindentation showed that the interlayer distance between GO sheets decreases after reduction allowing the increase of the Hardness and Young modulus that makes this material able to be manipulated and integrated on different devices. Furthermore, we also observe that exposed areas to electron beam reduction process show an increase in the electrical conductivity up to 3 × 104 times. The developed flexible GO films can have interesting applications such as biosensors or templates for inducing tissue regeneration, by providing a surface with differently patterned cues with contrasting electron mobility. Preliminary in vitro studies with L929 fibroblasts support the cytocompatible nature of this patterned GO paper.Gil Gonçalves thanks the Fundação para a Ciência e a Tecnologia for the PostDoc grant (SFRH/BDP/84419/2012). P.A.A.P.M. acknowledge the FCT/MCTES for a research contract under the Program Investigator 2013 (IF/00917/2013/CP1162/CT0016) and TEMA – Centre for Mechanical Technology and Automation (UID/EMS/00481/2013), financed by national funds through the FCT/MEC. I.B. wish to acknowledge the Portuguese Foundation for Science and Technology for the financial support (grant IF/00582/2015). H·I·S.N. acknowledges CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The biological studies of this work have been funded by the Ministerio de Economía y Competitividad and the Fondo Europeo de Desarrollo Regional (MAT2016-78857-R, MINECO/FEDER, UE). AGM and MCS acknowledge ISCIII-MINECO-FEDER for respective contracts. Authors would like to thank Dr M. Teresa Portolés from the Biochemistry and Molecular Biology Department at Universidad Complutense de Madrid for the generous supply of L929 fibroblasts. Dr José Ángel Rodríguez and Dr Javier Mazarío from the Service of Microscopy and Image Analysis at the Hospital Nacional de Parapléjicos are acknowledged for assistance with CLSM studies and Dr Enrique Rodríguez from the Servicio Interdepartamental de Investigación at the Universidad Autónoma de Madrid for SEM studies.info:eu-repo/semantics/acceptedVersio

Selective cell response on natural polymer bio-interfaces textured by femtosecond laser

This study reports on the evaluation of laser processed natural polymer-chitosan, which is under consideration as a biointerface used for temporary applications as skin and cartilage substitutes. It is employed for tissue engineering purposes, since it possesses a significant degree of biocompatibility and biodegradability. Chitosan-based thin films were processed by femtosecond laser radiation to enhance the surface properties of the material. Various geometry patterns were produced on polymer surfaces and employed to examine cellular adhesion and orientation. The topography of the modified zones was observed using scanning electron microscopy and confocal microscopy. Test of the material cytotoxicity was performed by evaluating the life/dead cell correlation. The obtained results showed that texturing with femtosecond laser pulses is appropriate method to initiate a predefined cellular response. Formation of surface modifications in the form of foams with an expansion of the material was created under laser irradiation with a number of applied laser pulses from N = 1-5. It is shown that irradiation with N > 5 results in disturbance of microfoam. Material characterization reveals a decrease in water contact angle values after laser irradiation of chitosan films. Consequently, changes in surface roughness of chitosan thin-film surface result in its functionalization. Cultivation of MC3T3 and ATMSC cells show cell orientational migration concerning different surface patterning. The influence of various pulse durations (varying from tau = 30-500 fs) over biofilms surface was examined regarding the evolution of surface morphology. The goal of this study was to define the optimal laser conditions (laser energy, number of applied pulses, and pulse duration) to alter surface wettability properties and porosity to improve material performance. The acquired set of results indicate the way to tune the surface properties to optimize cell-interface interaction