آپوپتوز سلول سرطانی ریه القا شده با میکرو پلاسما سرد بر پایه فیبر نوری قابل انعطاف

ABSTRACT Apoptosis of lung carcinoma cells induced by a flexible optical fiber-based cold microplasma

A plasma is an ionized medium that contains numerous active components including electrons and ions, free radicals, reactive molecules, and photons (Becker et al., 2006; Cooper et al., 2009; Kushner, 2005; Laroussi and Lu, 2005; Somekawa et al., 2005). Plasma treatment has been used for materials processing in order to impart desired surface characteristics on plastics, paper, textiles, semiconductors (Kim et al., 2006; Noeske et al., 2004; Temmerman et al., 2005; Yang and Yin, 2007). The demonstration of atmospheric plasma processes broadened the field to include treatment of materials that generally are unsuitable for vacuum processes. Such improvements in the state-of-the-art have led to the emergence of biological applications for plasmas. Plasmas can be categorized as either thermal (hot) or non-thermal (cold) (Tendero et al., 2006). In a thermal plasma, the electrons and heavy particles are in equilibrium with one another and the environment and the temperature of the heavy particles is nearly equal to that of the electrons. On the other hand, a non-thermal plasma shows very high electron temperatures but low gas temperatures due to a weak ionization rate.

Due to the large difference in mass, the electrons come into thermodynamic equilibrium among themselves much faster than they come into the equilibrium with the heavy particles, such as ions and neutral atoms. As a result, the overall temperature of the plasma can remain much cooler than the electron temperature, nearly the ambient temperature. Atmospheric non-thermal plasma treatments are being investigated for multiple biological applications including tissue sterilization, blood coagulation, wound healing, tissue regeneration, dental treatment, and the treatment of various diseases, including cancer (Fridman et al., 2008; Kong et al., 2009; Kim et al., 2010a,b; Lee et al., 2010; Morfill et al., 2009; Scholtz et al., 2010). The plasma cancer therapies that have been developed utilize excited radicals, including reactive oxygen species (ROS), and directly expose these to the tumor cells at macro-scale dimensions such that apoptosis is induced at a rapid pace (Fridman et al., 2008; Georgescu and Lupu, 2010; Kim et al., 2010b; Stoffels et al., 2008).
However, present devices are macro-sized and generally more rigid thus limiting the precise targeting of plasma treatment in internal organs.

Lung cancer is one of the most common cancers in North America for both men and women and is a leading cause of cancer-related deaths (Jemal et al., 2010) because the majority of lung cancers are inoperable. In order to better treat lung cancer using a non-thermal plasma, a plasma jet device should be flexible and small in diameter so that a well-defined plasma can be delivered to a specific biological site in the body. A hollow-core optical fiber serving as an effective conduit for a delivery of atmospheric pressure plasma has several advantages including excellent flexibility, very small diameter, mechanical robustness, chemical durability, and very low production cost. The flexible and micrometer-scale plasma jet devices with a hollow-core optical fiber could be utilized to access internal sites through minimally-invasive surgical procedures similar to an endoscopic within internal organs including the lungs. In addition, the flexible microplasma jet devices employing a hollowcore optical fiber with a low gas flow rate can prevent unwanted blood coagulations during the plasma treatment of tumor cells unlike the present plasma devices.

In this paper, a highly flexible microplasma jet device is developed using hollow-core optical fibers and their use in targeted cancer treatment therapies is investigated. This work permits new directed cancer therapies based on a highly flexible and preciselypositioned hollow optical fiber-based microplasma jet device and offers microplasma cancer endoscopy as a new physical cancer therapeutic method.