Plasma Polymer Processes in Biomedical Applications

Surface Science, 2008

Composite Ti/hydrocarbon plasma polymer films were deposited on silicon by dc magnetron sputtering of titanium in an atmosphere of argon and hexane. Different titanium concentration was obtained by careful adjustment of Ar/hexane ratio. With increasing Ti content, the surface potential and hardness increase as measured by Kelvin Force Microscopy and Visco-Elastic Atomic Force Microscopy, respectively. The adhesion force against silicon increased with increasing the titanium concentration as it was evaluated from the AFM force-distance curves. Fibrinogen adsorbs on the Ti/hydrocarbon plasma polymer films as a very soft layer with fibrinogen molecules adhering stronger to the Ti-rich films. Furthermore, the increase of the surface charge due to fibrinogen adsorption has been observed.

Biomaterials, 2007

The crucial factor of metal implant ingrowth in the bone is the rapid cellular acceptance. Therefore, the knowledge about additionally used adhesion mechanisms of osteoblasts, like their negatively charged hyaluronan coat, generates new surface functionalization strategies. Here, titanium was coated with a very thin, adherent, cross-linked, pinhole-and additive-free allylamine plasma polymer layer (PPAAm) resistant to hydrolysis and delamination and equipped with a high density of positively charged amino groups. This plasma polymer-functionalization of titanium is advantageous concerning osteoblastic focal adhesion formation as vinculin and paxillin, actin cytoskeleton development and, in consequence in differentiated cell functions, compared to a pure titanium surface-but similar such as the collagen I bonded surface via a polyethylenglycol-diacid (PEG DA)-spacer. r

Materials Science and Engineering: C, 2020

We evaluated the effects of titanium plasma nitriding and oxidation on live endothelial cell viscoelasticity. For this, mechanically polished titanium surfaces and two surfaces treated by planar cathode discharge in nitriding (36N 2 and 24H 2) and oxidant (36O 2 and 24H 2). Surfaces were characterized regarding wettability, roughness and chemical composition. Rabbit aortic endothelial cells (RAECs) were cultured on the titanium surfaces. Cell morphology, viability and viscoelasticity were evaluated by scanning electron microscopy (SEM), methyl thiazolyl tetrazolium (MTT) assay and atomic force microscopy (AFM), respectively. Grazing Incidence X-ray Diffraction confirmed the presence of TiN 0,26 on the surface (grazing angle theta 1°) of the nitrided samples, decreasing with depth. On the oxidized surface had the formation of TiO 3 on the material surface (Theta 1°) and in the deeper layers was noted, with a marked presence of Ti (Theta 3°). Both plasma treatments increased surface roughness and they are hydrophilic (angle < 90°). However, oxidation led to a more hydrophilic titanium surface (66.59°± 3.65 vs. 76.88°± 2.68; p = 0.001) due to titanium oxide films in their stoichiometric varieties (Ti 3 O, TiO 2 , Ti 6 O), especially Ti 3 O. Despite focal adhesion on the surfaces, viability was different after 24 h, as cell viability on the oxidized surface was higher than on the nitrided surface (9.1 × 10 3 vs. 4.5 × 10 3 cells; p < 0.05). This can be explained by analyzing the viscoelastic property of the cellular cytoskeleton (nuclear and peripheral) by AFM. Surface oxidation significantly increased RAECs viscoelasticity at cell periphery, in comparison to the nucleus (2.36 ± 0.3 vs. 1.5 ± 0.4; p < 0.05), and to the RAECs periphery in contact with nitrided surfaces (1.36 ± 0.7; p < 0.05) and polished surfaces (1.55 ± 0.6; p < 0.05). Taken together, our results have shown that titanium plasma treatment directly increased cell viscoelasticity via surface oxidation, and this mechanobiological property subsequently increased biocompatibility.

Plasma polymer deposition was applied for the preparation of nitrogen-containing functional layers for the improvement of cell performance at titanium implant model surfaces. The aging of the surface after storage of the substrate on air was monitored by XPS and FT-IR. It could be shown that the change of surface chemical properties of thin plasma polymerized coatings on titanium alloys has no significant influence on cell adhesion and spreading after up to one year of storage.

Macromolecular Bioscience, 2011

Low seeding efficiency and poor cell retention under flow-induced shear stress limit the effectiveness of in vitro endothelialization strategies for small-diameter vascular grafts. Primary-amine-rich plasma-polymerized coatings (PPE:N) deposited using low-and atmospheric-pressure plasma discharges on PET and PTFE are evaluated for their ability to improve endothelial cells' kinetics and strength of attachment. PPE:N coatings increase cell adhesion and adhesion rate, spreading, focal adhesion, and resistance to flow-induced shear compared with bare and gelatin-coated PET and PTFE. In particular, about 90% of the cells remain on coated surfaces after 1 h exposure to shear. These coatings, therefore, appear as a promising versatile approach to improve cell seeding strategies for vascular grafts.

Ciência &amp; Tecnologia dos Materiais, 2017

Biomedical devices introduced in the human body interact initially with blood cells, their success being dependent on the result of this interaction. This work aimed to obtain optimum biocompatibility and hemocompatibility of the titanium by plasma treatment. For this, discs of commercially pure titanium (CP) were subjected to plasma nitriding using different mixture of nitrogen and hydrogen; the effect of addition of hydrogen to the nitriding plasma was investigated. Before and after treatment, samples were evaluated in terms of topography and wettability using atomic force microscopy and sessile drop tests, respectively. The titanium biological response was evaluated in vitro through the application of platelet-rich plasma (PRP) on the surfaces modified and analysis of their behaviour from the point of view of surface tension and cell adhesion. Surface properties, such as roughness and wettability, were sensitive to the hydrogen/nitrogen ratio in the nitriding plasma, suggesting a strategy for producing different surfaces of biomedical devices. Results showed to be possible to obtain surfaces with different response to the adhesion of platelets, covering different applications.

Arxiv, 2025

Surface modification of polymeric biomaterials using plasma has emerged as an effective strategy to optimize the cell-material interface without compromising the structural properties of the material. This work presents a critical review of the impact of low-temperature plasma treatment on enhancing cell adhesion, with emphasis on the physicochemical changes induced on the surface of polymers commonly used in biomedical applications. The mechanisms of interaction between reactive plasma species and the polymer surface are analyzed, along with techniques used to introduce hydrophilic functional groups that improve wettability and biocompatibility. Scientific evidence demonstrates that this type of surface modification promotes greater cell spreading, anchorage, and proliferation, making it particularly useful in the design of tissue engineering scaffolds, implantable devices, and vascular prostheses. Finally, current and future trends in the development of smart plasma-functionalized biomaterials are discussed, highlighting their role in regenerative medicine.

A multi-step plasma-based functionalization procedure of titanium was designed to create bioactive surface properties. A combination of copper implantation by plasma ion immersion implantation (PIII) and functionalization with organic amino groups by plasma enhanced chemical vapor deposition (PE-CVD) was investigated with respect to physicochemical surface properties as well as antimicrobial activity and cell adhesion.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2003

Polymeric materials can be used in many application areas due to their mechanical (e.g. elastic) characteristics, chemical stability, and their light weight, as well as for their many design possibilities. Even in the fields of medicine and biotechnology many products are completely or partly made of polymers. In contact with biological systems, compatibility of these materials is not always given. To fulfill the requirements for medical applications, the surfaces have to be modified. Plasma techniques are demonstrated as an appropriate tool for the generation of the demanded surface properties. Experimental data are given for surface modification by plasma polymerization, with retention of the functional groups of the monomers used. Qualitative and quantitative characterization of the thin films with respect to the type and density of available groups at the surfaces is presented. Some possible applications of plasma-modified polymers are also discussed.

Scientific Reports, 2017

Nitrogen-containing plasma polymerization is of considerable interest for tissue engineering due to their properties on cell adhesion and mesenchymal stem cells (MSCs) response. In this study, low-pressure RF plasma of acetylene and nitrogen was used to deposit nitrogen-containing plasma polymerized coatings on several substrates. Deposition kinetics and surface characteristics of coatings were investigated in terms of RF power and gas flow ratio. OES was used to monitor the plasma process and investigate the relation between the film structure and plasma species. Presence of several bonds and low concentration of amine functional groups were determined using FTIR and Colorimetric methods. Contact angle goniometry results indicated about 30% increase in surface hydrophilicity. Stability of coatings in air and two different liquid environments was examined by repeating surface free energy measurements. Deposited films exhibited acceptable stability during the storage duration. Surface roughness measured by AFM was found to decrease with growing concentration of nitrogen. The deposition rate increased with increasing RF power and decreased with growing concentration of nitrogen. Zeta potential measurements of coatings revealed the negative potential on the surface of the thin films. Temporary suppression of collagen X in the presence of plasma coatings was confirmed by RT-PCR results.