Fabrication of filter membrane of organic compound to protect the upper respiratory tract from viral and bacterial infections, including SARS-CoV-2, compliant with FFP2 standard

Bacteria, viruses, and other pathogens in the surrounding environment are biological threat to human health and life. The development of various diseases in the world, as well as the pandemic caused by the rapid spread of the SARS-CoV-2 virus, have increased the demand for the use of upper respiratory protection devices. Out of concern for the natural environment, the aim of this work was to develop an innovative solution i.e. the FFP3 filtering membrane made of an organic compound. First, preliminary tests of the FFP2 mask were carried out to assess the chemical composition, morphological structure - fibers geometry, thickness, density, and arrangement. The FTIR analysis study was conducted to confirm that the main chemical in the mask was polypropylene (PP) and high-density polyethylene (HDPE). Optical, confocal microscopy and computer microtomography studies showed the fibers structure. They were densely arranged and their thickness was less than 1 den. The fiber structure of the FFP2 mask was also compared before and after immersing in betulin, an organic compound obtained from birch bark via the Soxhlet extraction. In addition, the assessment of microbiological activity was made on the reference strain Escherichia coli ATCC 25922, and the anti-inflammatory activity on normal human skin fibroblasts on polycarbonate with betulin. The studies showed that betulin supported the material antibacterial and anti-inflammatory properties.