Biocidal Mechanisms of Metallic Copper Surfaces - Use of Biocidal Surfaces for Reduction of Healthcare Acquired Infections - page 104

sophisticated instruments allowing civilizations to evolve from the Stone Age
[ 74 ]. Whereas gold was mainly used for luxury purposes, such as jewelry, use of
copper was of greater practical significance. Indeed, the first metal tools, imple-
ments and weapons were made from this metal. The rise of Eastern civilizations
(Egypt and Middle Eastern) flourished at the same time as they expanded the
knowledge on copper extraction and annealing [ 74 ]. During this times it was
noted that hammering and grounding of extracted copper pieces resulted in much
harder metal that can be used in production of many tools, an event that marked the
start of the Copper Age. Such treated copper was used for fabrication of many
utensils, including weapons, however their strength was not yet sufficient against
harder materials, such as bones [ 74 ]. This issue was solved by mixing two metals,
copper and tin, to produce a copper alloy which was stronger than either of each
individual metal. This alloy improved already existing tools and it enabled the
creation of new utensils, moving civilizations to the new era of the Bronze Age
[ 74 ]. Besides playing such distinguishing role in tools production, copper was also
known to prevent and treat infectious diseases, and disinfect fluids and solids
[ 19 , 91 ]. The Smith papyrus, an Egyptian medical document, (circa 2400 B.C.)
states that copper was used to sanitize drinking water and wounds. Copper oxide
and malachite, a copper carbonate mineral, was used in Mesoamerica by the Aztecs
to treat skin conditions. In ancient Greece, Hippocrates (400 B.C.), the “father” of
medicine, prescribed copper for pulmonary diseases and to disinfect drinking water
[ 19 ]. The Roman Empire used copper piping to improve public hygiene. Great
traders, like the early Phoenicians, in order to clean ship hulls for faster travel, fixed
copper strips on the ship bodies to inhibit biofouling. Furthermore, different
cultures throughout many continents dropped copper coins in water vessels to
prevent diseases like dysentery [ 19 ]. Until the nineteenth century, all these civili-
zations were using copper without knowledge of the existence of microorganisms.
Only when Antonie van Leeuwenhoek observed microscopic shapes in his newly
invented microscope, and Louis Pasteur in his Germ Theory of Disease emphasized
the notion that microscopic germs may lead to disease, copper usage gained a more
specific meaning: copper as a biocide. At the same time it was noted that copper
workers were not affected during a raging cholera epidemic in Paris. The employ-
ment of the metal and its salts in the subsequent century became widespread in
medicine: a variety of copper compounds were used to treat diseases such as
eczema, tubercular infections, and “The Great Pox”, syphilis. Nonetheless, with
the discovery of antibiotics pharmaceutical companies started to commercialize
these new drugs heavily forcing them into becoming the prevailing form of
infection treatment for humans and animals. Thus, the exploitation of copper as
an antimicrobial material was all but forgotten [ 17 ]. Nowadays, human healthcare
is confronted with the widespread occurrence of antibiotic resistant bacteria, and it
is, therefore, of great importance to revisit old methods, including the use of
copper, to improve and develop alternative therapeutic ways to treat and prevent
diseases.