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Polymer Surfaces (polymer + surface)
Selected AbstractsNovel Biomembrane-Mimicking Polymer Surface with Environmental ResponsivenessMACROMOLECULAR RAPID COMMUNICATIONS, Issue 17 2005Hong Tan Abstract Summary: In this article, we designed and synthesized novel segmented poly(carbonate urethane)s containing both hydrophobic fluorinated alkyl group and hydrophilic phosphatidylcholine polar head groups on the side chain. The contact angle measurement, XPS, together with ATR-IR investigation indicated a reversible overturn of the phosphatidylcholine groups with the movement of the hydrophobic fluorinated alkyl groups when the samples were treated in dry air or water. The change in environment from air to water induced a reorganization of the surface in order to minimize the interfacial free energy, resulting in a macroscopic change of surface wettability. The good environmental responsiveness of such biomembrane-mimicking films may find successful applications as biomaterials. Environmentally responsive surface using FPCPCU50 as an example; FPCPCU50 coated on aligned carbon nanotube film and dried in vacuum at 50,°C for 7 h and sample c treated in hot water at 80,°C for 1 h. [source] Micropatterned Polymer Surfaces and Cellular Response of Dictyostelium,ADVANCED ENGINEERING MATERIALS, Issue 5 2010Magdalena Eder Gecko inspired adhesives are surfaces with many microscale pillars that form Van der Waals forces with other surfaces. They differ from conventional tape in that adhesion is reversible and has the potential for switchability. These properties make gecko adhesives interesting for various biomedical applications. The two objectives of this project were to investigate the formation of biofilms on such surfaces and how the surfaces affect cell development. The developmental stages of the model organism Dictyostelium discoideum were observed by time lapse photography using light and environmental scanning electron microscopy. This study shows that micropatterned surfaces can be used as a biophysical tool to interfere with multicellular tissue formation in multiple ways. [source] Direct Evidence of Covalent Immobilisation of Microperoxidase-11 on Plasma Polymer SurfacesPLASMA PROCESSES AND POLYMERS, Issue 8 2010Yongbai Yin Abstract The question of whether immobilised proteins are bound covalently on plasma activated or deposited polymers has been a challenge for almost 30 years, as there has been no directly evidence to conclude unambiguously. In this paper, we report evidence that a chemical binding reaction occurred during immobilisation of microperoxidase-11 (MP-11) proteins on plasma polymer surfaces. Untreated polymer surfaces were not resistant to detergent cleaning and did not show any increase of S 2p component after protein immobilisation, whilst all plasma-deposited surfaces showed large amounts of immobilised MP-11 proteins after detergent cleaning. We conclude that the MP-11 protein had a chemical binding reaction thorough its cysteine residues with the plasma polymer surfaces. [source] Plasmabromination , the Selective Way to Monotype Functionalized Polymer SurfacesPLASMA PROCESSES AND POLYMERS, Issue 9 2007Sascha Wettmarshausen Abstract In contrast to other plasma modification processes of polymer surfaces, the bromination is very selective and shows a high yield in CBr groups. The most convenient bromination process was found using bromoform, which was thus preferred to elemental bromine, allyl bromide, vinyl bromide or tert -butylbromide. The bromoform process give yields in CBr up to 40 CBr or more, with only 2,3% co-introduction of O-functionalities whereas allyl bromide results in yields of about 20 CBr and more, but in more than 10% oxygen-containing by-products. CBr groups serve as anchoring points for grafting of molecules, oligomers and pre-polymers of diole or diamine character. [source] Back Cover (Phys. Status Solidi A 4/2010)PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2010Silvia Giudicatti In their Editor's Choice article on p. 935, Marabelli and coworkers present a study of plasmonic resonances in 2D planar periodic structures, which are constructed by colloidal lithography on gold/polymer surfaces. Strong interplay between plasmonic modes on both sample sides is found. The SEM image, top left on the back cover, shows the nanostructured gold/polymer surface: a residual polystyrene sphere from lithography is in the centre, whereas the top of acrylic acid pillars appear black. Reflectance from this surface passing through the glass substrate was investigated in a flowing cell, as depicted in the sketch on the right. Below, there is the map of angle dispersion of reflectance: lines represent the ideal plasmon polariton dispersion at the gold/glass and gold/air surfaces (solid lines) and the Wood anomalies (dashed lines). [source] A Solid-State Organic Electronic Wettability Switch,ADVANCED MATERIALS, Issue 4 2004J. Isaksson Solid-state devices based on soluble polymers on a rigid substrate, with the active surface facing the environment, have been designed and characterized. The contact angles and spreading of water droplets can be reversibly controlled by electrochemically reducing or oxidizing a polymer surface (see Figure). [source] Influence of cylinder-on-plate or block-on-ring sliding configurations on friction and wear of pure and filled engineering polymersLUBRICATION SCIENCE, Issue 2 2007P. Samyn Abstract Polyamides, polyesters and polyacetals are often used in line contacts under reciprocating or continuous sliding. These contacts are simulated on cylinder-on-plate (COP) or block-on-ring (BOR) tribotests. Comparative tests for pure, oil-filled and solid lubricated polymers at 100N and 0.3m/s are presented for relative material classification. Differences are discussed according to the sliding geometries. Thermal effects dominate friction and wear behaviour: the polymer glass transition temperature is exceeded in COP tests while the temperature is lower in BOR tests. Thick and brittle films are observed for pure polymers in BOR tests, promoting higher friction. The test configuration is mainly important for evaluation of internal lubricants. The efficiency of oil-lubricated polymers is not demonstrated in COP tests, while solid lubricants are not efficient in BOR tests. Deformation restricts the diffusion of oil lubricants in COP tests while solid lubricants are deposited on the polymer surface rather than being incorporated in the transfer film in BOR tests. Copyright © 2007 John Wiley & Sons, Ltd. [source] Adhesion mechanism of salmon to polymer-coated can wallsPACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2005Hans Dommershuijzen Abstract Minimization of the amount of salmon adhering to the can wall after emptying is one of the convenience requirements of consumers of canned salmon. In order to achieve this, the mechanism by which salmon adheres to cans needs to be understood. The aim of this study was to provide such knowledge for polymer-coated cans. The results indicate that gelatin, derived from salmon collagen, and myofibrillar proteins are the major proteins involved in sticking of salmon to the polymer-coated can wall. Furthermore, it was shown that mainly hydrogen bonds are formed between the salmon proteins and the polymer surface. Therefore, making the surface more apolar can prevent sticking of salmon to polymer-coated cans. Copyright © 2005 John Wiley & Sons, Ltd. [source] Surface characterization and study of Langmuir films of poly(4-vinylpyridine) quaternized with n -alkylbromidePOLYMER INTERNATIONAL, Issue 8 2001Ligia Gargallo Abstract The surface behaviour of poly(4-vinylpyridine)s (P4VP) quaternized with four different alkyl chains (pentyl, hexyl, octyl and decy bromide) were studied. Surface pressure,area isotherms (,,A) at the air,water interface were determined. Depending on the length of the side-chains, the ,,A isotherms show a plateau region. An extensive plateau is observed for n,>,6. The plateau pressures are similar for n,,=,8 and n,,=,10. The monolayers are stable and exhibit hysteresis phenomena. Brewster angle microscopy (BAM) is used to monitor the monolayer topography of the polymer on water subphase. To obtain information about the surface energy (SE) and the degree of hydrophobicity of these systems, we have estimated the critical surface tension, ,c, and the dispersion force and polar contributions to SE, ,D and ,P, respectively, by measurements of the contact angle (CA) of water and bromobenzene on the polymer surface. The results obtained are depend on the length of the alkyl lateral chain of the functionalized polymers. © 2001 Society of Chemical Industry [source] Quantification of chemical,polymer surface interactions in microfluidic cell culture devicesBIOTECHNOLOGY PROGRESS, Issue 2 2009Hui Xu Abstract Microfluidic cell culture devices have been used for drug development, chemical analysis, and environmental pollutant detection. Because of the decreased fluid volume and increased surface area to volume ratio, interactions between device surfaces and the fluid is a key element that affects the performance and detection accuracy of microfluidic devices, particularly if fluid is recirculated by a peristaltic pump. However, this issue has not been studied in detail in a microfluidic cell culture environment. In this study, chemical loss and contaminant leakage from various polymer surfaces in a microfluidic setup were characterized. The effects of hydrophilic coating with Poly (vinyl alcohol), Pluronic® F-68, and multi-layer ionic coating were measured. We observed significant surface adsorption of estradiol, doxorubicin, and verapamil with PharMed® BPT tubing, whereas PTFE/BPT and stainless steel/BPT hybrid tubing caused less chemical loss in proportion to the fraction of BPT tubing in the hybrid system. Contaminants leaching out of the BPT tubing were found to be estrogen receptor agonists as determined by estrogen-induced green fluorescence expression in an estrogen responsive Ishikawa cell line and also caused interference with an estradiol enzyme-linked immunosorbent assay (ELISA) assay. Stainless steel/BPT hybrid tubing caused the least interference with ELISA. In summary, polymer surface and chemical interactions inside microfluidic systems should not be neglected and require careful investigations when results from a microfluidic system are compared with results from a macroscale cell culture setup. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Plasma-Enhanced Atomic Layer Deposition of Palladium on a Polymer Substrate,CHEMICAL VAPOR DEPOSITION, Issue 6-7 2007A. Ten, Eyck Abstract In this paper, a method for the plasma-enhanced (PE) atomic layer deposition (ALD) of palladium on air-exposed, annealed poly(p -xylylene) (Parylene-N, or PPX) is presented. Palladium is successfully deposited on PPX at 80,°C using a remote, inductively coupled, hydrogen/nitrogen plasma with palladium (II) hexafluoroacetylacetonate (PdII(hfac)2) as the precursor. By optimizing the mixture of hydrogen and nitrogen, the polymer surface is modified to introduce active sites allowing the chemisorption of the PdII(hfac)2. In addition, enough free hydrogen atoms are available at the surface for ligand removal and Pd reduction, while at the same time, enough hydrogen atoms are consumed in the plasma to ensure there is no visible degradation of the PPX. X-ray photoelectron spectroscopy (XPS) measurements of the substrate after hydrogen/nitrogen plasma treatment at 50,W clearly show the presence of nitrogen bound to the substrate surface. XPS measurements of the deposited Pd films indicate good quality for both substrates, suggesting that the substrate temperature was low enough to prevent dissociation of the hfac ligand and adequate scavenging of the hfac ligand by the available atomic hydrogen. The remote hydrogen/nitrogen plasma enables Pd film deposition on polymer surfaces, which do not typically react with the Pd precursor, and are not catalysts for the dissociation of molecular hydrogen. [source] Reactive Imprint Lithography: Combined Topographical Patterning and Chemical Surface Functionalization of Polystyrene- block -poly(tert -butyl acrylate) FilmsADVANCED FUNCTIONAL MATERIALS, Issue 3 2010Joost Duvigneau Abstract Here, reactive imprint lithography (RIL) is introduced as a new, one-step lithographic tool for the fabrication of large-area topographically patterned, chemically activated polymer platforms. Films of polystyrene- block -poly(tert -butyl acrylate) (PS- b -PtBA) are imprinted with PDMS master stamps at temperatures above the corresponding glass transition and chemical deprotection temperatures to yield structured films with exposed carboxylic acid and anhydride groups. Faithful pattern transfer is confirmed by AFM analyses. Transmission-mode FTIR spectra shows a conversion of over 95% of the tert -butyl ester groups after RIL at 230,°C for 5 minutes and a significantly reduced conversion to anhydride compared to thermolysis of neat films with free surfaces in air or nitrogen. An enrichment of the surface layer in PS is detected by angle-resolved X-ray photoelectron spectroscopy (XPS). In order to demonstrate application potentials of the activated platforms, a 7,nm,±,1,nm thick NH2 -terminated PEG layer (grafting density of 0.9 chains nm,2) is covalently grafted to RIL-activated substrates. This layer reduces the non-specific adsorption (NSA) of bovine serum albumin by 95% to a residual mass coverage of 9.1,±,2.9,ng cm,2. As shown by these examples, RIL comprises an attractive complementary approach to produce bio-reactive polymer surfaces with topographic patterns in a one-step process. [source] Three-Dimensional Assembly of Polymer Microstructures at Low Temperatures ,ADVANCED MATERIALS, Issue 6 2004Y. Yang A low-temperature, low-pressure polymer bonding technique for three-dimensional assembly of microstructures (see Figure; scale bar 5 ,m) based on carbon dioxide (CO2)-enhanced chain entanglement near the polymer surfaces is presented. The environmentally benign utilization of supercritical CO2 offers scope for the production of polymer-based biomedical applications and devices. [source] Deposition of 90YPO4 and 144CePO4 radioisotopes on polymer surfaces for radiation delivery devicesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2002Xin Qu Abstract Intravascular irradiation with , emitters inhibits restenosis in arteries after balloon angioplasty or stent implantation. Yttrium-90 (90Y, T1/2=64 h) and cerium-144 (144Ce, T1/2=286 d) emit beta particles (Emax=2.28,3.50 MeV) having an ideal energy range for brachytherapy delivery system. In this article, a previously reported method for depositing 32P on poly(ethylene terephtalate) (PET) surfaces is generalized and modifications that allow deposition of other ,-emitting radioisotopes, such as 90Y and 144Ce, are demonstrated. PET films were first coated with chitosan hydrogel and then adsorbed different amounts of phosphoric acid (PA) in aqueous solutions. Yttrium was deposited onto the surface as YPO4 after the films were immersed in YCl3 solutions. 1 ,Ci 90YCl3 (2×10,9 g) was used in each sample as a tracer for measuring the deposition efficiency, which is defined as the percentage of YCl3 deposited on the surface compared to the amount of YCl3 in solutions before the deposition. In order to improve the safety of brachytherapy treatments, polyurethanes were used to seal the deposited radioisotopes on the surface to minimize the leakage of the isotopes into the patients. The generality of this method presented here for a wide variety of particular radioisotopic components allows design of a broad range of versatile radioisotope sources. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 98,105, 2002; DOI 10.1002/jbm.10095 [source] Surface modification of poly(glycolic acid) (PGA) for biomedical applicationsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2003Kyung-Bok Lee Abstract The immobilization of biological ligands (such as biotin and peptides) onto biodegradable polymer surfaces, including poly(glycolic acid) (PGA) sutures, is complicated by the absence of functional groups on the polymer backbone. We demonstrate a method for overcoming this problem, by attaching (+)-biotinyl-3,6,9-trioxaundecanediamine to the surface of PGA sutures, which immobilizes the ligand through an amide bond between amine (ligands) and carboxylic acid groups (surface-hydrolyzed PGA sutures). Fluorescence microscopy was used to verify the attachment of the biotin ligand to the surface of the PGA suture after a complexation with fluorescein-conjugated streptavidin. The strategy can be generalized to surface modifications of other biodegradable aliphatic polyesters, which would improve the properties of the polymers in biomedical applications such as active targeting of drugs based on ligand-attached, polymeric drug delvery systems. © 2003 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 92:933,937, 2003 [source] Integrated surface modification of fully polymeric microfluidic devices using living radical photopolymerization chemistryJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 4 2006Robert P. Sebra Abstract Surface modification using living radical polymerization (LRP) chemistry is a powerful technique for surface modification of polymeric substrates. This research demonstrates the ability to use LRP as a polymer substrate surface-modification platform for covalently grafting polymer chains in a spatially and temporally controlled fashion. Specifically, dithiocarbamate functionalities are introduced onto polymer surfaces using tetraethylthiuram disulfide. This technique enables integration of LRP-based grafting for the development of an integrated, covalent surface-modification method for microfluidic device construction. The unique photolithographic method enables construction of devices that are not substrate-limited. To demonstrate the utility of this approach, both controlled fluid flow and cell patterning applications were demonstrated upon modification with various chemical functionalities. Specifically, poly(ethylene glycol) (375) monoacrylate and trifluoroethyl acrylate were grafted to control fluidic flow on a microfluidic device. Before patterning, surface-functionalized samples were characterized with both goniometric and infrared spectroscopy to ensure that photografting was occurring through pendant dithiocarbamate functionalities. Near-infrared results demonstrated conversion of grafted monomers when dithiocarbamate-functionalized surfaces were used, as compared to dormant control surfaces. Furthermore, attenuated total reflectance/infrared spectroscopy results verified the presence of dithiocarbamate functionalities on the substrate surfaces, which were useful in grafting chains of various functionalities whose contact angles ranged from 7 to 86°. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1404,1413, 2006 [source] The use of post-mortem Raman spectroscopy in explaining friction and wear behaviour of sintered polyimide at high temperatureLUBRICATION SCIENCE, Issue 3 2006P. Samyn Abstract Due to their thermal stability and high strength, polyimides are an aromatic type of polymer that is used in sliding equipment functioning under high loads and elevated temperature. However, its tribological behaviour under high temperature and atmospheric conditions is not fully understood. It has been reported that a transition from high towards lower friction occurs ,somewhere' in the temperature region between 100°C and 200°C; however, a correlation with changes in the polyimide molecular structure remains difficult to illustrate and it is not certain whether or not this transition is correlated to lower wear. In the present work sliding experiments under controlled bulk temperatures between 100°C and 260°C are performed. A transition is observed in both friction and wear at 180°C which is further explained by microscopic analysis of the transfer film on the steel counterface and Raman spectroscopy of the worn polymer surfaces. A close examination of the spectra reveals transitions in relative intensity of certain absorption bands, pointing to different orientation effects of the molecular conformation at the polymer sliding surface at 180°C. Copyright © 2006 John Wiley & Sons, Ltd. [source] Direct Evidence of Covalent Immobilisation of Microperoxidase-11 on Plasma Polymer SurfacesPLASMA PROCESSES AND POLYMERS, Issue 8 2010Yongbai Yin Abstract The question of whether immobilised proteins are bound covalently on plasma activated or deposited polymers has been a challenge for almost 30 years, as there has been no directly evidence to conclude unambiguously. In this paper, we report evidence that a chemical binding reaction occurred during immobilisation of microperoxidase-11 (MP-11) proteins on plasma polymer surfaces. Untreated polymer surfaces were not resistant to detergent cleaning and did not show any increase of S 2p component after protein immobilisation, whilst all plasma-deposited surfaces showed large amounts of immobilised MP-11 proteins after detergent cleaning. We conclude that the MP-11 protein had a chemical binding reaction thorough its cysteine residues with the plasma polymer surfaces. [source] Plasmabromination , the Selective Way to Monotype Functionalized Polymer SurfacesPLASMA PROCESSES AND POLYMERS, Issue 9 2007Sascha Wettmarshausen Abstract In contrast to other plasma modification processes of polymer surfaces, the bromination is very selective and shows a high yield in CBr groups. The most convenient bromination process was found using bromoform, which was thus preferred to elemental bromine, allyl bromide, vinyl bromide or tert -butylbromide. The bromoform process give yields in CBr up to 40 CBr or more, with only 2,3% co-introduction of O-functionalities whereas allyl bromide results in yields of about 20 CBr and more, but in more than 10% oxygen-containing by-products. CBr groups serve as anchoring points for grafting of molecules, oligomers and pre-polymers of diole or diamine character. [source] Zero flash ultrasonic micro embossing on foamed polymer substrates: A proof of conceptPOLYMER ENGINEERING & SCIENCE, Issue 11 2009Srikanth G. Vengasandra This article reviews a novel method to produce microembossed features with an aspect ratio of three and negligible flash on polymer surfaces. An embossing technique that utilizes localized heating (ultrasonic energy) was used with polystyrene and polypropylene substrates. It was demonstrated that when foamed substrates were used, the amount of flash produced was negligible compared to nonfoamed substrates, which has been a significant unresolved problem with embossing using localized heating. The depth of microembossed features as a function of heating times and amplitudes of ultrasonic embossing is detailed in this article, along with a characterization of complex embossed geometries. It was seen that embossing depth was generally proportional to heating time and amplitude until the maximum feature depth was achieved. Although this article deals with embossing of microfeatures for lab-on-a-CD applications, it is envisioned that it is also suitable for lab-on-a-chip applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Understanding surfaces and buried interfaces of polymer materials at the molecular level using sum frequency generation vibrational spectroscopyPOLYMER INTERNATIONAL, Issue 5 2007Zhan Chen Abstract This paper reviews recent progress in the studies on polymer surfaces/interfaces using sum frequency generation (SFG) vibrational spectroscopy. SFG theory, technique, and some experimental details have been presented. The review is focused on the SFG studies on buried interfaces involving polymer materials, such as polymer,water interfaces and polymer,polymer interfaces. Molecular interactions between polymer surfaces and adhesion promoters as well as biological molecules such as proteins and peptides have also been elucidated using SFG. This review demonstrates that SFG is a powerful technique to characterize molecular level structural information of complicated polymer surfaces and interfaces in situ. Copyright © 2006 Society of Chemical Industry [source] Quantification of chemical,polymer surface interactions in microfluidic cell culture devicesBIOTECHNOLOGY PROGRESS, Issue 2 2009Hui Xu Abstract Microfluidic cell culture devices have been used for drug development, chemical analysis, and environmental pollutant detection. Because of the decreased fluid volume and increased surface area to volume ratio, interactions between device surfaces and the fluid is a key element that affects the performance and detection accuracy of microfluidic devices, particularly if fluid is recirculated by a peristaltic pump. However, this issue has not been studied in detail in a microfluidic cell culture environment. In this study, chemical loss and contaminant leakage from various polymer surfaces in a microfluidic setup were characterized. The effects of hydrophilic coating with Poly (vinyl alcohol), Pluronic® F-68, and multi-layer ionic coating were measured. We observed significant surface adsorption of estradiol, doxorubicin, and verapamil with PharMed® BPT tubing, whereas PTFE/BPT and stainless steel/BPT hybrid tubing caused less chemical loss in proportion to the fraction of BPT tubing in the hybrid system. Contaminants leaching out of the BPT tubing were found to be estrogen receptor agonists as determined by estrogen-induced green fluorescence expression in an estrogen responsive Ishikawa cell line and also caused interference with an estradiol enzyme-linked immunosorbent assay (ELISA) assay. Stainless steel/BPT hybrid tubing caused the least interference with ELISA. In summary, polymer surface and chemical interactions inside microfluidic systems should not be neglected and require careful investigations when results from a microfluidic system are compared with results from a macroscale cell culture setup. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Plasma-Enhanced Atomic Layer Deposition of Palladium on a Polymer Substrate,CHEMICAL VAPOR DEPOSITION, Issue 6-7 2007A. Ten, Eyck Abstract In this paper, a method for the plasma-enhanced (PE) atomic layer deposition (ALD) of palladium on air-exposed, annealed poly(p -xylylene) (Parylene-N, or PPX) is presented. Palladium is successfully deposited on PPX at 80,°C using a remote, inductively coupled, hydrogen/nitrogen plasma with palladium (II) hexafluoroacetylacetonate (PdII(hfac)2) as the precursor. By optimizing the mixture of hydrogen and nitrogen, the polymer surface is modified to introduce active sites allowing the chemisorption of the PdII(hfac)2. In addition, enough free hydrogen atoms are available at the surface for ligand removal and Pd reduction, while at the same time, enough hydrogen atoms are consumed in the plasma to ensure there is no visible degradation of the PPX. X-ray photoelectron spectroscopy (XPS) measurements of the substrate after hydrogen/nitrogen plasma treatment at 50,W clearly show the presence of nitrogen bound to the substrate surface. XPS measurements of the deposited Pd films indicate good quality for both substrates, suggesting that the substrate temperature was low enough to prevent dissociation of the hfac ligand and adequate scavenging of the hfac ligand by the available atomic hydrogen. The remote hydrogen/nitrogen plasma enables Pd film deposition on polymer surfaces, which do not typically react with the Pd precursor, and are not catalysts for the dissociation of molecular hydrogen. [source] Apatite Deposition on NaOH-Treated PEEK and UHMWPE Films for Sclera Materials in Artificial Cornea Implants,ADVANCED ENGINEERING MATERIALS, Issue 7 2010Monica Pino Abstract Cornea implants consist of a clear optic portion with a surrounding ring known as the skirt, which needs to integrate with the sclera. However, currently used skirt materials lead to poor tissue integration. Improvements in this respect may be achieved by using a bioactive skirt material that adapts to the metabolic activity of the cornea. Polyether etherketone (PEEK) and ultra-high molecular weight polyethylene (UHMWPE) might provide interesting alternatives, if they can be rendered bioactive. We, therefore, investigated the potential of surface-modifying PEEK and UHMWPE films through the use of a two-step treatment. This process involved a suitable chemical surface modification (via immersion in NaOH), with subsequent formation of apatite layers on the polymers' surfaces through exposure to supersaturated simulated body fluid (1.5 SBF). In the present work the effect of 5 and 10,M NaOH on formation of the apatite layer has been investigated with regard to wettability and topography features. In addition, the chemical stability of the apatite layer formed has been analyzed. Our data demonstrate that with an increase in NaOH concentration the wettability of the polymer increased, whilst some changes to the polymer film topography (increase/decrease in roughness) were observed. Most beneficially, the apatite layer that subsequently was grown on pre-treated PEEK and UHMWPE films through immersion in 1.5 SBF contained phosphate and carbonate ions, in similar ratios to those found in the apatite in dentine, thus, promising good in vivo bioactivity of these polymer films,a necessity if they are to be integrated into artificial cornea. [source] | |||||||||||||||||||||||||