Etching rates of blood proteins, blood plasma and polymer in oxygen afterglow of microwave plasma

Abstract

The removal of biomolecules from medical instruments by plasma could be a difficult task due to the fact that many medical instruments are made of polymers, which can be etched in plasma as well. The etching rates of selected blood proteins, platelet‐poor plasma (PPP) and polymer polyethylene terephthalate (PET) were studied. In the case of blood proteins, fibrinogen (FIB) and human serum albumin (HSA) were used. Films of PPP, FIB, HSA and PET were deposited on the quartz crystals and exposed to oxygen atoms in early and late afterglow of microwave plasma at different pressures between 50 and 400 Pa. The thickness of the films versus etching time was measured by quartz crystal microbalance. The thickness of PET film decreased linearly with etching time, while the thickness of both protein films and PPP decreased exponentially with time. In all cases, the etching rates were first increasing with the increasing pressure, while later they reached a constant value. Furthermore, the etching rates were higher in the early afterglow than in the late afterglow. The etching rates of PPP were higher than the etching rates of both proteins HSA and FIB. The slowest etching rate was observed for PET polymer, where the etching rate was lower by two orders of magnitude in comparison to both proteins and PPP. Copyright © 2014 John Wiley & Sons, Ltd.

Selective Plasma Etching of Polymeric Substrates for Advanced Applications

“…Another supportive application of plasma etching in the bio-medical field is plasma sterilization of surgical devices, drug packaging, or processing of other medical objects [ 59 , 60 ]. For example, on exposure to reactive O 2 plasma neutral radical in the afterglow, the blood proteins and microorganisms showed exponential etching rate, whereas the PET substrate exhibited only a linear etching rate [ 61 ]. These distinct etching rates help to remove toxins or other organic contaminants from the surface without affecting the surgical equipment or medical material.…”

Physicochemical and Biological Investigation of Different Structures of Carbon Coatings Deposited onto Polyurethane

“…It is mainly connected with the chemical character of the interaction between oxygen free-radicals and modified substrate. In this field, oxygen plasma is known to be one of the most aggressive agents in polymer degradation, or modification (Vesel et al 2014). Resulting surface chemical structure may possibly improve the adhesion of the coating by increasing free surface energy of PU substrate by bonding oxygen to carbon atoms on their surface (Hauert 2004).…”

Oxygen content dependent etch rate of single polymer microparticles confined in the sheath region of a low pressure radiofrequency argon/oxygen plasma

“…Oxygen plasmas can be used to etch a variety of organic polymers [22]. Although the exact mechanism of polymer etching by oxygen is not fully understood, atomic oxygen is believed to play a dominant role.…”