Figure 3
Glidden Vinyl Latex coated paper swatches with
and without ProteCoat testedagainst five different
bacterial isolates of interest in coatings.
ty against many different types of bacteria, yeast, mold,
fungi and some viruses and algae.
The effectiveness and general applicability of ProteCoat
AMPs in paint formulations has been tested in a variety of
formulations against a variety of microorganisms and
under a variety of conditions. In one test, the additive was
mixed with the styrene-acrylic emulsion polymer UCAR
451 from the Dow Chemical Company and painted onto the
bottom of sample wells. 20 Each well was exposed to a solution containing spores of three different microorganisms:
Aspergillus nididans, a model for A. fumigatus, a potentially fatal human pathogen; Bacillus atrophaeus, a non-toxic
analog used by the U.S. military for the anthrax-producing
B.cmthracis; and Fusarium oxysporum, a plant fungus and
potential human pathogen.
ProteCoat exhibited activity against all three microbes,
confirming that AMPs retain their broad spectrum antimi-
crobial functionality when added to cured films. The prod-
uct can also be applied separately to the top of an already
applied coating and is slightly more effective this way than
when mixed into the paint.20b In other tests, ProteCoat
proved to be effective against clinically-important bacteria
when incorporated into a vinyl latex and used to coat paper
discs. The bioadditive was shown to reduce by 5-6 logs the
contamination of five different strains of bacteria (see
Figure 3). In tests of exterior architectural coatings,
ProteCoat was shown to significantly reduce the microbial
growth on an unprimed flat latex used to coat cedar paint
fence panels over an 18-month exposure while north facing
at a 90° incline (see Figure 4).
ANTIBODIES, VIRUSES AND CELLS
More recently, researchers have begun to explore the possibility of incorporating other active bioadditives into paints
and coatings, including antibodies, viruses and both whole
cells and parts of them.
Antibodies are gamma globulin proteins that detect and
destroy bacteria, viruses and other foreign objects. Each
anti-body has a unique structure at the tip of the protein
called the antigen binding site that is designed to target a
specific antigen—typically a virus or bacterium. Due to the
nearly endless possible variants of the antigen binding site,
antibodies can be created to target and bind a vast number
of potential pathogens or other problem molecules. In the
body, the antigen, once bound by the antibody, is marked for
destruction by other biochemicals in the immune system.
Figure 4: Unprimed flat latex on cedar with ProteCoat, facing North 90˚ after 18-month exposure
Latex w/ProteCoat
Latex w/o
ProteCoat
Latex w/o ProteCoat 20x magnification Close-up 1000x magnification
Latex w/ProteCoat 20x magnification Close-up 1000x magnification
Eighteen-month fence panel testing of exterior latex coatings with and without ProteCoat, side-by-side comparison (leftmost side without
rightmost side with ProteCoat); the images at right are close ups—including microscopic microbial growth photographs—of the same panel.
