Researchers from University of Maryland, College Park, and University of California, Berkeley, plan to investigate atmospheric pressure plasma (APP) sources for modification of selected model biomolecules and to establish a scientific framework for development of atmospheric pressure plasma applications in biotechnology and plasma medicine (or biomedicine). Non-equilibrium atmospheric pressure plasmas are powerful sources for reactive chemical species that can have profound biological effects, but the sources are complex, poorly understood, and are difficult to design and control. Our knowledge of the nature of the plasma-biomaterial interaction using such atmospheric pressure plasma sources is especially inadequate. This work combines plasma source characterization/simulations, plasma-surface (tissue) treatments/in-situ surface characterization with biological assay methodologies, and various characterization approaches, including magnetic resonance characterization of solid state and solution macromolecules. The broader impacts of this project go beyond the establishment of baseline methodologies that can be used to characterize and control interactions of APP sources with biological targets. As an enabling technology, approaches and concepts unveiled in this work can be broadly applied in diverse applications where the biological environment must be well-controlled, e.g. disinfection of packaging for food and medicines, modification of biological systems, cells and tissue, including the field of plasma medicine. The principles under study in this project are also relevant to all applications of APP for surface functionalization of organic materials such as polymers.
The project's first objective is to obtain a fundamental understanding of how fluxes of reactive species produced in two representative APP devices depend on source type, operating parameters and environmental conditions using relevant chemistries. The second objective is to expose selected biomolecules to well controlled species from these APP sources to induce atomistic modifications of the biomolecules. The changes in biomolecule properties (chemical, morphological etc) along with alterations in biological function will be characterized using an array of complementary methods. Furthermore, modifications in biological function will be correlated with the results of the comprehensive materials/surface characterizations to provide underlying chemical and biological mechanisms. The third objective is to obtain a scientific understanding of how water modulates APP-biomolecule interactions to affect its biological function. This includes establishment of differences in APP species fluxes, chemical/morphological changes in biomolecules, and their biological responses to bio-assays when water is present either in the gas stream passing through the APP source, the environment (humidity) or as a liquid on the surface of the biomolecule. The fourth objective is experimental validation of current computational efforts on simulating atomic-scale modifications of specific model biomolecules by reactive species produced by APP sources. This will be based on investigating biomolecules for which atomic-scale simulations of the interaction of reactive plasma species with these biomolecules have either been published, or are currently ongoing.
