Degradation of micro-nano-sized polytetrafluoroethylene and acrylic fluorinated copolymer particles in the periwinkle digestive tract.

The aim of the work was to investigate the possible biodegradation of such stable plastics as fluorated acrylic copolymer Protacryl-M and polytetrafluoroethylene-teflon (PTFE)-that are widely applied in medicine for prosthetics in dentistry and orthopedics. Our tasks were as follows: 1. To select a suitable marine biological object (multicellular invertebrate) 2. To develop a method for delivering microplastic particles (MP) of selected plastics to the gastrointestinal tract (GIT) of an experimental animal 3. To develop a technique for separating MP particles from animal feces 4. To develop a technology for multiple passages of MP particles through the gastrointestinal tract of an animal 5. To select methods and techniques for determining the degradation of the surface of MP particles after passing through the gastrointestinal tract of the animal The effect of a biological agent on the types of plastic above is considered using marine gastropods of the genus Littorina (in particular, the periwinkle L. brevicula) as a model organism widely distributed in the marine intertidal zone.

Micro-nano-sized polytetrafluoroethylene (teflon) particles as a model of plastic pollution detection in living organisms.

Micro- and nano-sized particles of polytetrafluoroethylene (PTFE) were used as model (reference) particles to study the biological effects of plastic pollution. Since the PTFE molecule contains fluorine, considered as an "atomic marker" sharply distinguishing it from other common plastics, micro- and nano-particles of PTFE have a specific crystalline structure and are, therefore, well identified by the methods of polarized light microscopy (POL), Raman microspectroscopy (micro-Raman), and energy-dispersive spectroscopy (EDS). Examples of PTFE particles detection in hemolimph of the cockroach Blatella germanica, in hemolimph of the larva and in faecal pellets of imago of a fly Lucilia sp., in the stomach and hingat of brine shrimp Artemia salina, and in association with cell wall of green unicellular alga Chlorococcus sp. are provided. The presented results strongly suggest that PTFE particles can be detected and identified in the biological medium using the method of "atomic markers", polarization microscopy and Raman spectroscopy.