A compact pulse-modulation cold air plasma jet for the inactivation of chronic wound bacteria: development and characterization

Abstract

A compact low-temperature plasma jet device was developed to use ambient air as plasma gas. The device was driven by a 2.52-kV high-voltage direct-current pulse in a burst mode, with a repetition rate of 2 kHz. The maximum plasma discharge current was 3.5 A, with an approximately 10 ns full-width half-maximum. Nitric oxide, hydroxyl radical, atomic oxygen, ozone, and hydrogen peroxide—important reactive oxygen and nitrogen species (RONS)—were mainly produced. The amount of plasma-generated RONS can be controlled by varying the pulse-modulation factors. After optimization, the plasma plume length was approximately 5 mm and the treatment temperature was less than 40 °C. The preliminary bactericidal effects were tested on Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant S. aureus (MRSA), and their biofilms. The results showed that the plasma can effectively inactivate S. aureus, P. aeruginosa, and MRSA in both time- and pulse-dependent manner. Thus, this produced plasma device proved to be an efficient tool for inactivating deteriorating bacteria. Further versatile utilization of this portable plasma generator is also promising.

Improved Osteogenesis of Selective-Laser-Melted Titanium Alloy by Coating Strontium-Doped Phosphate With High-Efficiency Air-Plasma Treatment

“…Therefore, treatment methods to enhance the bioactivity of the material surface should be employed. Air-plasma treatment enhances the surface properties of materials and has been utilized in agricultural production, waste management, as well as surface cleaning and disinfection (Petlin et al, 2017;Messerle et al, 2018;Saberi et al, 2018;Thana et al, 2019). The main advantages of this process are thin film deposition, increased wettability, induced cross-linking, and surface activation of the material.…”

Surface barrier discharges for Escherichia coli biofilm inactivation: Modes of action and the importance of UV radiation

“…It has been demonstrated that Gram-negative bacteria are more sensitive than Gram-positive bacteria to CAP, a phenomenon likely to occur due differences in the cell wall thickness [ 5 ]. In agreement with our observation, Olatunde and co-workers [ 52 ] proposed the production of UV as one of the major factors in the mode of action in Gram-negative bacterial inactivation by CAP.…”

“…Plasma—regarded as the fourth state of matter—is a partially or completely ionised gas with unique chemical and physical properties which generates a wide range of highly reactive chemical agents when created in the ambient air. It has been increasingly studied due its antimicrobial, blood coagulation, wound healing and anti-tumour capability as well as in dentistry and several other biomedical applications [ 1 – 5 ]. The development of Cold Atmospheric Plasma (CAP) has brought advantages over widely used vacuum plasma technologies such as easier handling, inexpensive cost and straightforward design [ 6 ].…”

Air to H2-N2 Pulse Plasma Jet for In-Vitro Plant Tissue Culture Process: Source Characteristics

“…COMPACT Air Plasma Jet, which is a coaxial kHz-driven pulsed plasma source, was used in this work. The details of the device are described elsewhere [ 14 ]. Briefly, the burst repetition rate (BRR), which is defined as an inverse of one pulse period, was set to 20 kHz and the pulse width was 5.0 μs.…”

“…Gas temperature of the plasma was estimated from a thermal equilibrium between a plasma-treated glass plate and the plasma plume as described in our previous work [ 14 ]. The plasma nozzle was perpendicularly set to the 22 mm × 22 mm × 0.16 mm glass plate with the gap distance of 5 mm.…”