| 1. |
- Golda-Cepa, M., et al.
(författare)
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Multifunctional PLGA/Parylene C Coating for Implant Materials : An Integral Approach for Biointerface Optimization
- 2016
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 8:34, s. 22093-22105
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Tidskriftsartikel (refereegranskat)abstract
- Functionalizing implant surfaces is critical for improving their performance. An integrated approach was employed to develop a multifunctional implant:coating based on oxygen plasma-modified parylene C and drug-loaded, biodegradable poly(DL-lactide-co-glycolide) (PLGA). The key functional attributes of the coating (i.e., anti-corrosion, biocompatible, anti-infection, and therapeutic) were thoroughly characterized at each fabrication step by spectroscopic, microscopic, and biologic methods and at different scales, ranging from molecular, through the nano- and microscales to the macroscopic scale. The chemistry of each layer was demonstrated separately, and their mutual affinity was shown to be indispensable for the development of versatile coatings, for implant applications.
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| 2. |
- Golda-Cepa, M., et al.
(författare)
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Microbiological investigations of oxygen plasma treated parylene C surfaces for metal implant coating
- 2015
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Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems. - : Elsevier. - 0928-4931 .- 1873-0191. ; 52, s. 273-281
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Tidskriftsartikel (refereegranskat)abstract
- Parylene C surface was modified by the use of oxygen plasma treatment and characterized by microscopic and surface-sensitive techniques (E-SEM, AFM, XPS, LDI-TOF-MS, contact angle). The influence of the treatment on surface properties was investigated by calculations of surface free energy (Owens-Wendt method). Moreover, early adhesion (Culture Plate Method, Optical Microscopy Test) and biofilm formation ability (Cristal Violet Assay) on the parylene C surface was investigated. The bacteria strains which are common causative agents of medical device-associated infections (Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa - reference strains and clinical isolates) were used. It was concluded that chemical (oxygen insertion) and physical (nanotopography generation) changes, have a significant impact on the biocompatibility in terms of increased hydrophilicity (θw of unmodified sample = 88° ± 2°, θw of 60 min modified sample = 17.6° ± 0.8°) and surface free energy (SFE of unmodified sample = 42.4 mJ/m2, and for 60 min modified sample = 70.1 mJ/m2). At the same time, no statistical effect on biofilm production and bacteria attachment to the modified surface of any of the tested strains was observed.
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| 3. |
- Adolfsson, Karin H., et al.
(författare)
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Importance of Surface Functionalities for Antibacterial Properties of Carbon Spheres
- 2019
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486.
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Tidskriftsartikel (refereegranskat)abstract
- Carbon spheres (CS) are interesting materials for antibacterial applications. Herein, CS are produced by a green process utilizing microwave-assisted hydrothermal treatment of cellulose. The CS are then postmodified in acidic and basic solutions to evaluate the influence of different functionalities on antibacterial properties. CS contain OH/COOH, C Symbol of the Klingon Empire C, and C Symbol of the Klingon Empire O functionalities, while O-CS produced by acid treatment of CS have additional COOH, and NH/NH2 groups, resulting in carbon spheres with negatively and positively charged groups in dispersion. Treatment with base (Na-CS) removes low molecular weight species with oxygen and results in carbon spheres with the highest C/O ratio. CS, O-CS, and Na-CS have nonporous morphology and are in micro/nanometer sizes, although, smaller sized spheres, hollow spheres, and fragments are also attained in the case of O-CS. O-CS show antibacterial activity toward both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Pseudomonas aeruginosa (P. aeruginosa). The minimum inhibitory concentration is 200 and 400 mu g mL(-1) for S. aureus and P. aeruginosa, respectively, and is achieved only after 3 h of incubation. Neither CS nor Na-CS exhibit antibacterial activity. The antibacterial activity is suggested to originate from electrostatic interactions between O-CS and the bacteria.
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| 4. |
- Duch, J., et al.
(författare)
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Work function modifications of graphite surface via oxygen plasma treatment
- 2017
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 419, s. 439-446
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Tidskriftsartikel (refereegranskat)abstract
- The surface modification of graphite by oxygen plasma was investigated experimentally (X-ray diffraction, nanoparticle tracking analysis, laser desorption ionization mass spectrometry, thermogravimetry, water contact angle) and by molecular modelling (Density Functional Theory). Generation of surface functional groups (mainly –OHsurf) leads to substantial changes in electrodonor properties and wettability gauged by work function and water contact angle, respectively. The invoked modifications were analyzed in terms of Helmholtz model taking into account the theoretically determined surface dipole moment of graphite—OHsurf system (μ = 2.71 D) and experimentally measured work function increase (from 0.75 to 1.02 eV) to determine the –OH surface coverage (from 0.70 to 1.03 × 1014 groups cm−2). Since the plasma treatment was confined to the surface, the high thermal stability of the graphite material was preserved as revealed by the thermogravimetric analysis. The obtained results provide a suitable quantitative background for tuning the key operating parameters of carbon electrodes: electronic properties, interaction with water and thermal stability.
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| 5. |
- Golda-Cepa, M., et al.
(författare)
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Development of crystalline-amorphous parylene C structure in micro-and nano-range towards enhanced biocompatibility : the importance of oxygen plasma treatment time
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 5:60, s. 48816-48821
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Tidskriftsartikel (refereegranskat)abstract
- The crystalline-amorphous parylene C structure was fabricated by Chemical Vapour Deposited (CVD) and functionalised in the micro- and nano-range with the oxygen plasma treatment. The evolution of thermal stability, structure and surface biocompatibility of parylene C films as an effect of oxygen plasma treatment time were evaluated by means of thermogravimetric/differential thermal analysis (TG/DTA), X-Ray Diffraction (XRD) and cells adhesion tests (crystal violet assay, fluorescence microscopy). The results are epitomized by a crystalline-amorphous parylene C structural model. It was found that the time of oxygen plasma treatment is critical for adhesion of osteoblast cells with the optimum of 5-8 minutes.
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| 6. |
- Golda-Cepa, M., et al.
(författare)
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LDI-MS examination of oxygen plasma modified polymer for designing tailored implant biointerfaces
- 2014
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 4:50, s. 26240-26243
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Tidskriftsartikel (refereegranskat)abstract
- A versatile polymer coating for biomaterials was fabricated by the mild oxygen plasma treatment of Chemical Vapour Deposited (CVD) parylene C. The surface properties were tailored while the excellent protective properties of the bulk were preserved. The species, formed due to the plasma functionalisation, were fingerprinted by a novel Laser Desorption/Ionisation-Mass Spectrometry (LDI-MS) method. Improved osteosarcoma cells (line MG-63) attachment and viability on a modified surface were demonstrated.
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| 7. |
- Golda-Cepa, M., et al.
(författare)
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Recent progress on parylene C polymer for biomedical applications : A review
- 2020
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Ingår i: Progress in organic coatings. - : Elsevier. - 0300-9440 .- 1873-331X. ; 140
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Forskningsöversikt (refereegranskat)abstract
- Parylene C films have numerous advantages. The versatility of parylene C coatings makes them useful in a broad range of biomedical applications. The coatings are widely used commercially because of the unique combination of their physicochemical properties, i.e. flexibility and dielectricity. The chemical vapour deposition process enables parylene C conformal coatings to be applied to even the most complex medical devices. The coatings can be customised for the desired application using surface modification methods, which alter surface chemistry and topography. In this review, we summarise the last ten years (2008–2018) of research on parylene C for biomedical applications. We discuss how parylene C properties can be modulated through surface and bulk modifications to improve its key functions, i.e. anticorrosive, biocompatible, anti-infection, and therapeutic functions. We emphasise current and potential biomedical applications and finally highlight the advantages and limitations of the coatings, pointing out the perspectives and the most promising research trends.
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