Tinneke Jacobs

Enhanced cell-material interactions on medium-pressure plasma-treated polyhydroxybutyrate/polyhydroxyvalerate

In this article, a medium-pressure DBD plasma treatment is used to improve the cell-material interaction of a polyhydroxybutyrate/polyhydroxyvalerate (PHB/PHV) film. PHB/PHV is a biodegradable natural polyester, used for different biomedical applications, including sutures, repair devices, and bone marrow scaffolds. The cell adhesion onto PHB/PHV is far less than optimal due to inadequate surface properties, and a surface modification is usually necessary to be able to use the full potential. Medium-pressure plasma treatments, in different atmospheres, are used to change the surface properties of a PHB/PHV foil. The hydrophilic character could be increased, as shown by water contact angle measurements. X-ray photoelectron spectroscopy (XPS) revealed an increased oxygen and nitrogen content. Cell culture test with human foreskin fibroblasts showed that the plasma was able to improve cell adhesion (both quantitatively and qualitatively). Both an increase in the number of adherent cells and an improved morphology were obtained after plasma treatment. After 7 days, a confluent cell layer could be observed on plasma-treated samples. The differences between the three discharge gases are negligible when looking at the improved cell-material interactions. From economical point of view, treatments in air are thus the best choice.

Visualization of the Penetration Depth of Plasma in Three-Dimensional Porous PCL Scaffolds

A dielectric barrier discharge (DBD) discharge is used to modify the surface properties of 3-D porous polycaprolactone (PCL) scaffolds. After plasma treatment, the penetration of blue ink into the samples was used to determine the effectiveness of the plasma treatment inside the structures. It was found that the ink could penetrate deeper into the scaffolds after plasma treatment.

The effect of medium pressure plasma treatment on thin poly-ϵ-caprolactone layers

Abstract In this work, the effect of medium pressure plasma treatment on thin poly-ϵ-caprolactone (PCL) layers on glass plates is investigated. PCL is a biocompatible and biodegradable polymer which potentially can be used for bone repair, tissue engineering and other biomedical applications. However, cell adhesion and proliferation are inadequate due to its low surface energy and a surface modification is required in most applications. To enhance the surface properties of thin PCL layers spin coated on glass plates, a dielectric barrier discharge (DBD) at medium pressure operating in different atmospheres (dry air, argon, helium) was used. After plasma treatment, water contact angle measurements, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were used to examine the PCL samples. These measurements show that the medium pressure plasma treatment is able to increase the hydrophilic character of the samples, due to an incorporation of oxygen groups at the surface and that the surface roughness is significantly decreased after plasma treatment.

Plasma surface treatment of biomedical polymers to improve cell adhesion

Summary form only given. Biomedical polymers have a great potential in medicine due to their biocompatible nature and versatility. However, their low surface energy leads to a cell adhesion and proliferation that is far less then optimal. To make them excellent candidates for implants and tissue engineering scaffolds, a surface modification is required.

Influence of successive plasma treatments on PP foils

Polypropylene (PP) foil is treated with a dielectric barrier discharge (DBD) plasma operating in helium at medium pressure. The influence of exposure to the atmosphere between successive treatments is studied by varying the exposure time. Each PP sample is treated with subsequent treatment steps of 5 s. Between two treatment steps, different procedures are applied: 1) the sample remains in the discharge chamber at medium pressure (under helium atmosphere) for a certain time before it is treated again or 2) the pressure is increased to atmospheric pressure, so the sample remains exposed to atmospheric air for a certain time and afterwards the system is pumped down again to medium pressure before it undergoes a successive helium plasma treatment. The treated samples are analysed using contact angle measurements. The results show that exposure to the atmosphere between two treatment steps leads to a lower contact angle. The longer the exposure time, the lower the contact angle becomes. Another experiment showed that the treatment effect could be gradually removed by applying several short plasma treatments of 1 s to saturated samples. With every short treatment step, the contact angle becomes higher. It is believed that this is due to etching of the surface. In the near future, both atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) analysis on some selected samples are planned to elucidate the chemical and/or physical nature of the observed phenomena.