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Thin polymeric coatings are commonly used for altering surface properties and modulating the interfacial performance of materials. Possible contributions from the substrate to the interfacial forces and effects are, however, usually ignored and are not well understood, nor is it established how the coating thickness modulates and eventually eliminates contributions from substrates to the van der Waals (vdW) interfacial force. In this study we quantified, by colloid-probe atomic force microscope (AFM) and by theoretical calculations, the interfacial vdW contributions from substrates acting through ethanol plasma polymer (EtOHpp) coatings of a range of thicknesses on Au and Si bulk materials. In approach force curves against EtOHpp-coated Au substrates the magnitude of the vdW force decreased as the EtOHpp coating thickness increased to 18 nm and then plateaued with further increases in coating thickness, providing direct evidence for a contribution to the total interfacial vdW force from the Au substrate acting through thin coatings. The experimental observations accord with theoretical calculations of the thickness dependence of Hamaker coefficients derived from rigorous simulation using the Lifshitz theory. In addition, the measured forces agree well with theoretical predictions including correction for finite roughness. Thus, our experimental and theoretical results establish how the thickness of polymer thin film coatings modulates the total interfacial vdW force and how this can be used to tune the net vdW force so as to either contain a large substrate contribution or arise predominantly from the polymeric overlayer. Our findings enable rational design of coating thickness to tailor interfacial interactions and material performance. Refereed/Peer-reviewed

This study aims at deposition and characterization of antibacterial, hydrophobic and semitransparent metal/plasma polymer nanocomposite coating, containing Ag nanoparticles, onto cotton fabrics intended to be used in medical applications. The nano composite coatings were obtained via a simple, one step and ecofriendly plasma based co-deposition approach where silver was magnetron sputtered simultaneously with plasma polymerization of hexamethyldisiloxane (HMDSO) monomer. The nanocomposite thin films containing different concentration of silver were deposited either by varying silver sputter rate or thickness of the plasma polymer matrix to obtain a good balance between optical properties of the coated fabric and its long term antibacterial performance. The obtained coatings were investigated in detail with respect to their composition, morphology, optical properties, nanoparticle size distribution, silver ion release efficiency, antibacterial performance, water contact angle and washing stability of the coating. The thickness of the plasma matrix was found to be more important in controlling the release of silver ions as well as affecting the optical properties of the coating. The water contact angle on the coated fabric was up to 145°, close to super hydrophobicity. The coating showed effective antibacterial efficacy against Staphylococcus epidermidis (a Gram positive bacterium) which was present even when fabric was subjected to 10 repeated washing cycles indicating good washing stability of the coating.

International audience; The affinity and repartition of silver nanoparticles in different plasma polymer matrices are studied according to the polymer functional groups. The polymer layers are synthesized by plasma polymerization of allyl alcohol (AAl), aniline (ANI), or heptadecafluoro-1-decene (HDFD). The matrix is then impregnated in a metallic salt solution and a reducing one. When plasma polymerized (pp) ANI is used as matrix, a higher amount of silver nanoparticles (AgNPs) is introduced compared to the other two polymer matrices. Otherwise, with pp-AAl, smaller AgNPs with narrower size distribution are inserted. Finally, different plasma polymer/AgNPs interaction mechanisms are proposed according to the polymer functional groups. Moreover, the sensing behavior of pp-ANI, well-known as sensitive layer towards ammonia, is markedly enhanced by the presence of AgNPs.

To combat infections on biomedical devices, antimicrobial coatings have attracted considerable attention, including coatings comprising naturally occurring antimicrobial peptides (AMPs). In this study the aim was to explore performance upon extended challenge by bacteria growing in media above samples. The AMPs LL37, Magainin 2, and Parasin 1 were selected on the basis of well-known membrane disruption activity in solution and were covalently grafted onto a plasma polymer platform, which enables application of this multilayer coating strategy to a wide range of biomaterials. Detailed surface analyses were performed to verify the intended outcomes of the coating sequence. Samples were challenged by incubation in bacterial growth media for 5 and 20 h. Compared with the control plasma polymer surface, all three grafted AMP coatings showed considerable reductions in bacterial colonization even at the high bacterial challenge of initial seeding at 1 &times, 107 CFU, but there were increasing numbers of dead bacteria attached to the surface. All three grafted AMP coatings were found to be non-toxic to primary fibroblasts. These coatings thus could be useful to produce antibacterial surface coatings for biomaterials, though possible consequences arising from the presence of dead bacteria need to be studied further, and compared to non-fouling coatings that avoid attachment of dead bacteria.

The aim of this study was to evaluate whether the surface modification of expanded polytetrafluoroethylene (ePTFE) using an n-heptylamine (HA) plasma polymer would allow for functional epithelial monolayer formation suitable for subretinal transplant into a non-dystrophic rat model. Freshly isolated iris pigment epithelial (IPE) cells from two rat strains (Long Evans [LE] and Dark Agouti [DA]) were seeded onto HA, fibronectin-coated n-heptylamine modified (F-HA) and unmodified ePFTE and fibronectin-coated tissue culture (F-TCPS) substrates. Both F-HA ePTFE and F-TCPS substrates enabled functional monolayer formation with both strains of rat. Without fibronectin coating, only LE IPE formed a monolayer on HA-treated ePTFE. Functional assessment of both IPE strains on F-HA ePTFE demonstrated uptake of POS that increased significantly with time that was greater than control F-TCPS. Surgical optimization using Healon GV and mixtures of Healon GV: phosphate buffered saline (PBS) to induce retinal detachment demonstrated that only Healon GV:PBS allowed F-HA ePTFE substrates to be successfully transplanted into the subretinal space of Royal College of Surgeons rats, where they remained flat beneath the neural retina for up to 4 weeks. No apparent substrate-induced inflammatory response was observed by fundus microscopy or immunohistochemical analysis, indicating the potential of this substrate for future clinical applications. Refereed/Peer-reviewed

Polyoxazoline thin coatings were deposited on glass substrates using atmospheric pressure plasma polymerization from 2-ethyl-2-oxazoline vapours. The plasma polymerization was performed in dielectric barrier discharge burning in nitrogen at atmospheric pressure. The thin films stable in aqueous environments were obtained at the deposition with increased substrate temperature, which was changed from 20◦ C to 150◦ C. The thin film deposited samples were highly active against both S. aureus and E. coli strains in general. The chemical composition of polyoxazoline films was studied by FTIR and XPS, the mechanical properties of films were studied by depth sensing indentation technique and by scratch tests. The film surface properties were studied by AFM and by surface energy measurement. After tuning the deposition parameters (i.e., monomer flow rate and substrate temperature), stable films, which resist bacterial biofilm formation and have cell-repellent properties, were achieved. Such antibiofouling polyoxazoline thin films can have many potential biomedical applications. © MDPI AG. All rights reserved., Czech Science FoundationGrant Agency of the Czech Republic [GACR 19-15240S]; Ministry of Defence of the Czech Republic

Background Biomaterial modifications—chemical and topographical—are of particular importance for the integration of materials in biosystems. Cells are known to sense these biomaterial characteristics, but it has remained unclear which physiological processes bio modifications trigger. Hence, the question arises of whether the dynamic of intracellular calcium ions is important for the characterization of the cell–material interaction. In our prior research we could demonstrate that a defined geometrical surface topography affects the cell physiology; this was finally detectable in a reduced intracellular calcium mobilization after the addition of adenosine triphosphate (ATP). Results This new contribution examines the cell physiology of human osteoblasts concerning the relative cell viability and the calcium ion dynamic on different chemical modifications of silicon–titanium (Ti) substrates. Chemical modifications comprising the coating of Ti surfaces with a plasma polymerized allylamine (PPAAm)-layer or with a thin layer of collagen type-I were compared with a bare Ti substrate as well as tissue culture plastic. For this purpose, the human osteoblasts (MG-63 and primary osteoblasts) were seeded onto the surfaces for 24 h. The relative cell viability was determined by colorimetric measurements of the cell metabolism and relativized to the density of cells quantified using crystal violet staining. The calcium ion dynamic of osteoblasts was evaluated by the calcium imaging analysis of fluo-3 stained vital cells using a confocal laser scanning microscope. The positively charged nano PPAAm-layer resulted in enhanced intracellular calcium ion mobilization after ATP-stimulus and cell viability. This study underlines the importance of the calcium signaling for the manifestation of the cell physiology. Conclusions Our current work provides new insights into the intracellular calcium dynamic caused by diverse chemical surface compositions. The calcium ion dynamic appears to be a sensitive parameter for the cell physiology and, thus, may represent a useful approach for evaluating a new biomaterial. In this regard, reliable in vitro-tests of cell behavior at the interface to a material are crucial steps in securing the success of a new biomaterial in medicine.

This contribution reviews plasma polymer nanoparticles produced by gas aggregation cluster sources either via plasma polymerization of volatile monomers or via radio frequency (RF) magnetron sputtering of conventional polymers. The formation of hydrocarbon, fluorocarbon, silicon- and nitrogen-containing plasma polymer nanoparticles as well as core@shell nanoparticles based on plasma polymers is discussed with a focus on the development of novel nanostructured surfaces.

Polyoxazolines are a new promising class of polymers for biomedical applications. Antibiofouling polyoxazoline coatings can suppress bacterial colonization of medical devices, which can cause infections to patients. However, the creation of oxazoline-based films using conventional methods is difficult. This study presents a new way to produce plasma polymerized oxazoline-based films with antibiofouling properties and good biocompatibility. The films were created via plasma deposition from 2-methyl-2-oxazoline vapors in nitrogen atmospheric pressure dielectric barrier discharge. Diverse film properties were achieved by increasing the substrate temperature at the deposition. The physical and chemical properties of plasma polymerized polyoxazoline films were studied by SEM, EDX, FTIR, AFM, depth-sensing indentation technique, and surface energy measurement. After tuning of the deposition parameters, films with a capacity to resist bacterial biofilm formation were achieved. Deposited films also promote cell viability.

The amount and distribution of metal nanoparticles in a plasma polymer matrix are studied according to the chemical structure of the polymer and the nature of the metal. The structure of the polymer (polyallylalcohol) is modified by varying the plasma parameters such as polymerization time, input power and discharge time. This study, done with silver, shows that when the polymer contains a lot of functional groups (here hydroxyl ones) with a rough surface, a high amount of silver, homogeneously distributed is inserted into the polymer. Moreover, three metals are studied: Ag, Cu and Sn. A higher quantity of silver and tin ions is inserted into the matrix compared to copper. Finally, two routes for the incorporation of silver nanoparticles are studied where the impregnation with the metallic salt and its reduction are done either in two stages or in one step with a single solution containing both the metallic salt and the reducing agent. The first method allows obtaining a higher amount of loaded silver with a homogeneous dispersion in the matrix.

In this article, an atmospheric pressure surface dielectric barrier discharge (SDBD) generated in helium has been studied for its discharge characteristics and its ability to generate amine functionalised polymer coatings for application in cell therapy. The electrical and optical properties of the surface plasma generated SDBD consisting of a mesh electrode are presented. Current-voltage measurements and intensified charge coupled device (ICCD)camera images showed that the plasma device is able to generate glow like discharge structures that are stable over the area of the electrodes at applied voltages ranging from 3.5 kV to 5 kVpk-pk. Most importantly, the plasma images show evidence of high electric fields around the hexagonal grid of the mesh electrode. Through the helium line ratio method, the density and temperature of electrons in the discharge was estimated between 1011–1012 cm3 and 0.3–0.8 eV respectively as a function of gas flow.Surface characterisation of the allylamine plasma polymer coating (ppAAm) with X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) showed that the coating is rich in amine functionality. However, atomic force microscopy (AFM) analysis show that the thickness of the coating is spatially nonuniform. From the results, it is predicted that the high amine functionality of the coating could be applied in cell adhesion and growth. Refereed/Peer-reviewed

Made available in DSpace on 2018-12-11T16:45:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-25 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Deposition of plasma polymers using atmospheric pressure plasma jet in mixture of argon, air and hexamethyldisilazane (HMDSN) was studied. The HMDSN monomer, used as film precursor, was carried to the jet nozzle by an auxiliary airflow and mixed with principal argon flow. The films were deposited for different times using mean discharge power of 2.8 W, main argon flow of 1 SLM while the carrier flow (air + HMDSN) was 0.1 SLM. The water contact angles measured across the obtained HMDSN plasma polymer film showed two well-defined areas, one hydrophilic, with contact angle near zero degrees and one hydrophobic, with contact angle around 100 degrees. The FTIR spectra showed that part of the original structure of HMDSN monomer was preserved and new chemical bonds were observed. XPS analysis showed that the deposited coatings are inorganic SiO2-like coatings. The films thickness was evaluated and it reached values about 2 μm in the center and decreased to the border (in continuous deposition mode more rapidly than in the pulsed one). Roughness values were obtained and it is shown that they varied for each region of the film. UNESP São Paulo State University, Av. Dr. Ariberto Pereira da Cunha INP Leibniz-Institute for Plasma Science and Technology, Felix-Hausdorff Str. 2 UNESP São Paulo State University, Av. Dr. Ariberto Pereira da Cunha

// Sudhir Bhatt 1, 3 , Fatemeh Valamanesh 2 , Jerome Pulpytel 1 , Rea Lo Dico 2 , Aliby Baiyukha 1 , Iman Al-dybiat 2 , Marc Pocard 2 , Farzaneh Arefi-Khonsari 1 , Massoud Mirshahi 2 1 Sorbonne Universites, UPMC Univ. Paris 6, CNRS, Laboratoire Interfaces et Systemes Electrochimiques, 75005, Paris, France 2 Sorbonne Paris Cite Universites, UMR Univ. Paris 7, INSERM U965 Carcinose, Angiogenese et Recherche Translationnelle, L’Hopital Lariboisiere, 75010, Paris, France 3 Current address: Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, 23508, VA, USA Correspondence to: Massoud Mirshahi, email: massoud.mirshahi@inserm.fr Keywords: plasma polymers, biodegradable coatings, in vivo drug delivery system, anti-cancer drug, targeted therapy Received: May 11, 2016 Accepted: July 19, 2016 Published: July 29, 2016 ABSTRACT A low pressure plasma process based on plasma deposition has been used to develop a drug delivery strategy. In this study, a drug delivery system based on different layers of plasma co-polymerized Poly e-caprolactone-Polyethylene glycol (PCL-PEG) co-polymers was deposited on biocompatible substrates. Cis-platinum (118 μgm/cm 2 ) was used as an anti-cancer drug and incorporated for local delivery of the chemotherapeutic agent. The co-polymer layers and their interaction with cancer cells were analyzed by scanning electron microscopy. Our study showed that the plasma-PCL-PEG coated cellophane membranes, in which the drug, was included did not modify the flexibility and appearance of the membranes. This system was actively investigated as an alternative method of controlling localized delivery of drug in vivo . The loading of the anti-cancer drug was investigated by UV-VIS spectroscopy and its release from plasma deposited implants against BALB/c mice liver tissues were analyzed through histological examination and apoptosis by TUNEL assay. The histological examination of liver tissues revealed that when the plasma-modified membranes encapsulated the cis-platinum, the Glisson’s capsule and liver parenchyma were damaged. In all cases, inflammatory tissues and fibrosis cells were observed in contact zones between the implant and the liver parenchyma. In conclusion, low pressure plasma deposited uniform nano-layers of the co-polymers can be used for controlled release of the drug in vivo.

Infections caused by the bacterial colonization of medical devices are a substantial problem to patients and healthcare. Biopassive polyoxazoline coatings are attracting attention in the biomedical field as one of the potential solutions to this problem. Here, we present an original and swift way to produce plasma-deposited oxazoline-based films for antifouling applications. The films developed via the plasma deposition of 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline have tunable thickness and surface properties. Diverse film chemistries were achieved by tuning and optimizing the deposition conditions. Human-derived fibroblasts were used to confirm the biocompatibility of oxazoline derived coatings. The capacity of the coatings to resist biofilm attachment was studied as a function of deposition power and mode (i.e., continuous wave or pulsed) and precursor flow rates for both 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline. After careful tuning of the deposition parameters films having the capacity to resist biofilm formation by more than 90% were achieved. The substrate-independent and customizable properties of the new generation of plasma deposited oxazoline thin films developed in this work make them attractive candidates for the coating of medical devices and other applications where bacteria surface colonization and biofilm formation is an issue. Refereed/Peer-reviewed

International audience; The present study proposes an alternative eco-friendly method to prepare a thin composite coating based on graphene embedded in siloxane polymers which can be used as application for the corrosion protection of steel. The nanocomposite coatings were elaborated by a dielectric barrier discharge using a nebulized colloidal suspension of graphene nanosheets (GNs) dispersed in hexamethyldisiloxane (HMDSO) used as the precursor for the polymer matrix. After obtaining a stable colloidal solution, it was nebulized into the plasma reactor to form a plasma polymer (pp) coating from HMDSO (ppHMDSO) in which GNs were incorporated (GN@ppHMDSO) on the mild steel substrate. The chemical structure of the hybrid coatings was characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectrometry. Raman spectra of GNs and GN@ppHMDSO coatings suggest the existence of charge transfer between the GNs and the HMDSO matrix. Furthermore, scanning electron microscopy confirms the synthesis of micro/nanocomposite with a fairly homogeneous dispersion of the GNs in the polymer matrix. The corrosion resistance of the samples was evaluated by electrochemical impedance spectroscopy which showed that the hybrid coatings GN@ppHMDSO deposited by a one-step atmospheric pressure plasma process, presented excellent anticorrosion performance with 99.99% of protection efficiency.

Plasma coatings deposited from oxazoline precursors have recently emerged as a valuable utility in many biotechnology application, however, their wider utilization by researchers and industry rely on their long term performance, and more specifically on the retention of their reactivity. Yet, plasma polymers are known to be susceptible to post-fabrication oxidation processes and intrinsic restructuration. Here,the aging of coatings deposited from oxazoline precursors was studied over12 months via XPS, ToF-SIMS,and sessile drop contact angle analysis for samples stored under various conditions. The extent of the damages caused by light and oxygen are identified and explained. Storage away from ambient light and undervacuum proved to retain highreactivity toward COOH-bearingligand and biomolecules even 12 months post deposition. Refereed/Peer-reviewed

Polymeric surfaces can benefit from functional modifications prior to using them for biological and/or technical applications. Surfaces considered for biocompatibility studies can be modified to gain beneficiary hydrophilic properties. For such modifications, the preparation of highly hydrophilic surfaces by means of plasma polymerization can be a good alternative to classical wet chemistry or plasma activation in simple atomic or molecular gasses. Atmospheric pressure plasma polymerization makes possible rapid, simple, and time-stable hydrophilic surface preparation, regardless of the type and properties of the material whose surface is to be modified. In this work, the surface of polypropylene was coated with a thin nanolayer of plasma-polymer which was prepared from a low-concentration mixture of propane-butane in nitrogen using atmospheric pressure plasma. A deposition time of only 1 second was necessary to achieve satisfactory hydrophilic properties. Highly hydrophilic, stable surfaces were obtained when the deposition time was 10 seconds. The thin layers of the prepared plasma-polymer exhibit highly stable wetting properties, they are smooth, homogeneous, flexible, and have good adhesion to the surface of polypropylene substrates. Moreover, they are constituted from essential elements only (C, H, N, O). This makes the presented modified plasma-polymer surfaces interesting for further studies in biological and/or technical applications.

We present a low-temperature versatile protocol for the fabrication of plasma nanocomposite thin films to act as tunable emitters and optical gain media. The films are obtained by the remote plasma-assisted deposition of a 4-(dicyano-methylene)-2-methyl-6-(4-dimethylamino-styryl)-4H-pyran (DCM) laser dye alongside adamantane. The experimental parameters that determine the concentration of the dye in the films and their optical properties, including light absorption, the refractive index, and luminescence, are evaluated. Amplified spontaneous emission experiments in the DCM/adamantane nanocomposite waveguides show the improvement of the copolymerized nanocomposites’ properties compared to films that were deposited with DCM as the sole precursor. Moreover, one-dimensional distributed feed-back laser emission is demonstrated and characterized in some of the nanocomposite films that are studied. These results open new paths for the optimization of the optical and lasing properties of plasma nanocomposite polymers, which can be straightforwardly integrated as active components in optoelectronic devices., The authors thank the European Regional Development Funds program (EU-FEDER), the Junta de Andalucia (TEP8067), and the Spanish Ministry of Economy and Competitiveness (Project Nos. MAT2016-79866-R, MAT2013-40852-R, MAT2013-42900-P, MAT2014-51937-C3-1-P, RECUPERA 2020, and IJCI-2014-21226) for their financial support.

The success of stem cell therapies relies heavily on our ability to control their fate in vitro during expansion to ensure an appropriate supply. The biophysical properties of the cell culture environment have been recognised as a potent stimuli influencing cellular behaviour. In this work we used advanced plasma-based techniques to generate model culture substrates with controlled nanotopographical features of 16 nm, 38 nm and 68 nm in magnitude, and three differently tailored surface chemical functionalities. The effect of these two surface properties on the adhesion, spreading, and self-renewal of mouse embryonic stem cells (mESCs) were assessed. The results demonstrated that physical and chemical cues influenced the behaviour of these stem cells in in vitro culture in different ways. The size of the nanotopographical features impacted on the cell adhesion, spreading and proliferation, while the chemistry influenced the cell self-renewal and differentiation. Refereed/Peer-reviewed

Current organ transplantation protocols require the rapid transport of freshly isolated donor tissue to the recipient patient at the site where the procedure is to be conducted. During transport, the tissue graft can quickly deteriorate as a result of oxygen starvation. In this study, we report the fabrication of oxygen-releasing coatings for improved tissue preservation. The coatings were prepared via the encapsulation of calcium peroxide or urea peroxide microparticles between layers of octadiene plasma polymer films. By varying the thickness of the plasma polymer coating and type of peroxide, formulations were obtained that generate oxygen upon contact with aqueous solutions, while at the same time limiting the amount of toxic reactive oxygen species produced. The optimized coatings were tested under hypoxic conditions using the MIN6 β-cell line, which resulted in a 3-fold increase in the viability of cultured cells. These thin oxygen-releasing coatings can be deposited on a wide range of surfaces, creating a platform for oxygen delivery with the potential to extend the viability of transported tissues and increase the time frame available for graft transport. Refereed/Peer-reviewed

The understanding of cell–surface interactions plays an important role for the biomaterials development and bioengineering. Although it is already known that amine groups increase the cell adhesion and proliferation, the influence of amine layers properties on cell viability is the subject of further investigation. In this work, amine-rich coatings were prepared by low pressure plasma polymerization of cyclopropylamine using radio frequency (RF) capacitively coupled discharge. Normal human dermal fibroblasts were chosen for the monitoring of biological response to the properties of amine layers. As a superior technique for the label-free monitoring of the cell–surface interaction, coherence-controlled holographic microscopy (CCHM) was exploited. CCHM enables quantitative phase imaging. From such images, valuable morphological parameters of cells directly related to the cell dry mass can be extracted. Based on those parameters, viability of cells cultivated on the plasmatreated surfaces with different properties was studied and evaluated. According to the results, amine-rich films enhanced the conditions for the cell adhesion and proliferation. Pochopení interakce buněk s povrchem hraje důležitou roli pro vývoj biomateriálů. I když je již známo, že aminové skupiny zvyšují adhezi buněk a proliferaci, vliv vlastností aminových vrstev na životaschopnost buněk je předmětem dalšího výzkumu. Vrstvy bohaté na aminové skupiny byly připraveny pomocí nízkotlaké plazmové polymerizace cyklopropylaminu. Lidské dermální fibroblasty byly vybrány pro sledování biologické reakce na vlastnosti aminových vrstev. Jako vhodná technika pro sledování interakce buněk s povrchem byla využívána koherencí řízená holografická mikroskopie (CCHM).

International audience; This paper describes the impact of a physical immobilization methodology, using plasma polymerized 1,1,3,3, tetramethyldisiloxane, on the catalytic performance of β-galactosidase from Aspergillus oryzae in a microfluidic device. The β-galactosidase was immobilized by a polymer coating grown by Plasma Enhanced Chemical Vapor Deposition (PEVCD). Combined with a microchannel patterned in the silicone, a microreactor was obtained with which the diffusion through the plasma polymerized layer and the hydrolysis of a synthetic substrate, the resorufin-β-D-galactopyranoside, were studied. A study of the efficiency of the immobilization procedure was investigated after several uses and kinetic parameters of immobilized β-galactosidase were calculated and compared with those of soluble enzyme. Simulation and a modelling approach were also initiated to understand phenomena that influenced enzyme behavior in the physical immobilization method. Thus, the catalytic performances of immobilized enzymes were directly influenced by immobilization conditions and particularly by the diffusion behavior and availability of substrate molecules in the enzyme microenvironment.

Plasma polymerization, so called Remote Plasma Enhanced Chemical Vapour Deposition (RPECVD) has been increasingly used in microsystems field. Plasma polymers served primarily as supports for electronic sensors or carriers for biomolecules and cell attachment1. This work describes the first use of plasma thin film deposition for the easy, fast and reduced cost fabrication of microfluidic channels. A new method named “plasma polymerization on a micropatterned surface” (PPMS) is presented. First, micropatterns representing the desired channels were designed on a silicon wafer, either by lithography of a sacrificial photoresist or by plasma etching of the Si substrate. Then, the patterned substrate was introduced into the reaction chamber of a home-made microwave (2.45 GHz) plasma reactor1. The organosilicon monomer 1,1,3,3,TetraMethylDiSiloxane was used as the precursor to synthetize and deposit a polymer organosilicon film by a remote afterglow PECVD2. The deposited polymer is used as the structural material of the microfluidic network.