In ancient times, the first metals discovered and used were gold, copper and silver, in that
order. Among the ashes of fire pits used by Stone Age peoples are the remains of
metallurgical work. Discoverers associated the yellow color of gold with the sun. In turn,
the white brightness of silver became associated with the moon. The Greek word argyros
is derived from a Sanskrit root mean shining white. In Latin, the moon is known as luna.
The surgical cauterizer made from silver nitrate and niter is still known as lunar caustic
today. The later Latin name argentum comes from an Aryan root meaning white and
shining. The word silver is of Gothic origin meaning shiny white. The optical properties
of silver are distinctive because of its exceptionally high reflectivity and very low
For thousands of years, silver has been highly regarded as a versatile healing tool. In
ancient Greece, Rome, Phoenicia and Macedonia, silver was used extensively to control
infections and spoilage. Hippocrates, the “Father of Medicine,” taught that silver healed
wounds and controlled disease. Around 400 B.C., he listed as a singular treatment for
ulcers “the flowers of silver alone, in the finest powder.” Herodotus describes how the
King of Persia carried with him boiled water in silver flagons to prevent sickness. In 69
B.C., silver nitrate was described in the contemporary Roman pharmacopoeia. Pliny the
Elder, in his survey of the world’s knowledge, Natural History (78 A.D.), states in Book
XXXIII, Section XXXV, that the slag of silver “… has healing properties as an ingredient
in plasters, being extremely effective in causing wounds to close up…”
The popularity of medicinal silver especially arose from 702 A.D. through 980 A.D.
throughout the Middle East where it was widely used and esteemed for blood
purification, heart conditions, and controlling halitosis. Paracelsus (circa 1520)
extensively incorporated silver medicinally, and later Caradanus, Pareus and Sala also
used it. Angelus Sala used silver nitrate to successfully treat chorea, tabes dorsalis
(syphilis), and “doubtably epilepsy”. These crude forms of silver were reported by Sala to
rarely cause the bluish hue of skin discoloration due to its overuse (Argyria). It is widely
thought that during the Middle Ages, silver utensils and goblets contributed a bluish hue
to the skin tone of the upper class, resulting in the term “royal blue bloods.” Plausibly the
term “born with a silver spoon in his mouth” was coined during that time for the same
reason, as an attribute for describing the good fortune of health more than having wealth.
These blue bloods were noted to have obtained a measure of protection from the rampant
plagues common to Europe in those centuries. The use of silver to provide bacteria-free
tableware, pacifiers and storage vessels has been practiced throughout history. Today it is
known that metallic silver will dissolve in water to the level of 10-5 g/l, which is toxic to
Escherichia coli and Bacillus typhosus.
Pioneers of the American West would often put a silver dollar into a jar or container of
milk to help keep it fresh without refrigeration. They would also drop silver and copper
coins in their barrels of drinking water to combat bacteria and algae. During the wars
with Napoleon, the armies of Tsar Alexander used water casks lined with silver to clean
drinking water from rivers and streams. This practice by the Imperial Russian army was
common through World War I and continued to be incorporated by some units in the
Soviet Army during World War II.
Raulin recorded the first clinical description of the water-cleansing effect by silver in
1869. He observed that Aspergillus niger could not grow in silver vessels.
Modern Research using the Scientific Method In 1861, Thomas Graham found that
certain solutions would pass through a membrane and others would not. He found a
stable, intermediate state of matter and was able to describe it. Graham discovered that
substances could enter a solution in such a manner that they would exhibit characteristics
quite different from those of a true solution. He applied the term “colloidal” (from kolla =
glue) to this intermediate state, since glue, gelatin, and related substances were the most
obvious to him as being in this unique state.
The Swiss botanist von Nageli recorded one of the amazing discoveries of the 19th
Century in 1869. Von Nageli coined the term “oligodynamic” to describe the
microbiocidal properties of a metal hydrosol (e.g. copper, silver and tin) at minute
concentrations. Silver is unique in its action against micro-organisms.
Recent studies confirm that silver ions are active against bacteria at concentrations as low
as one part per billion in pure water. Silver ions react rapidly with the walls of
prokaryotic cells typical of micro -organisms, whereas the membranes of eukaryotic cells
of mammals strongly resist any effect by silver.
In 1884, the German obstetrician C.S.F. Crede, observed that there was a 79%
relationship between blind children and maternal venereal disease. He subsequently
introduced a prophylactic l% silver nitrate eye solution for newborns for the prevention
of ophthalmia neonatorum. Following its introduction, the incidence of eye disease in
newborns dropped to about 0.2%. His treatment was a milestone in clinical prophylaxis
and became a government regulation throughout most of the world. By 1897, silver
nitrate began to be used in America to prevent blindness in newborns and is still used
today. By 1910, Henry Crookes had documented that certain metals, when in a colloidal
state, had strong germicidal action, but were harmless to human beings. The
oligodynamic concept motivated the development of many antimicrobial processes and
One of the water purification developments that took place in 1928 was the development
of Katadyn silver, described as a porous metallic, spongy mesh that attempts to maximize
surface area. This silver meshwork also contains a small quantity of gold or palladium.
Katadyn silver has been used inside flasks and storage containers and with water filters.
Both the U.S. and Russian space shuttle vehicles use electrified silver and copper water
Many urologic implements were made of silver and commonly used during the period of
1930 to 1960. This author has a Keyes-Ultzman silver urethral canula designed to reach
the prostatic urethra. The advent of inexpensive stainless steel and improved sterilization
methods greatly diminished the clinical market for silver implements.
During World War II, Charles L. Fox, a surgeon, observed that many soldiers died of
uncontrolled bacterial infection in open wounds. He had long used silver nitrate as part of
his medical practice, but it was far too aggressive with protein structures – limiting its
clinical uses. His research at the Department of Surgery and Microbiology, College of
Physicians and Surgeons, Columbia University, New York, led to the discovery of silver
sulfadiazine. This combination provided controlled release of silver ions in a wound
along with an active antibiotic drug. Silver sulfadiazine provided a steady, long-term
delivery of silver ions onto or into a wound. This combination remains a medical
milestone in the treatment of burn wounds and is the standard against which all other
burn wound treatments are measured. It is a dual antagonist: silver has the primary
activity against pathogens but should an organism be sensitive to sulfonamids, the
sulfadiazine component will also be active. This dual function has been extensively
studied to show effectiveness against a wide range of bacteria, fungi, extracellular viruses
During the last century, advances in pharmacological manufacturing methods sought to
harness this time-valued strategy expressed in nearly all silver formulations. Yet early
manufacturing methods rarely created high quality, homogeneous oligodynamic silver.
Nevertheless, more than 96 different silver medicinals (many used intravenously) were in
use prior to 1939, as documented by the Council on Pharmacy and Chemistry of the
American Medical Association. The introduction of Argyrol, a silver-protein compound
that provided silver ions for minor illnesses, was one of the most successful silver-based
preparations. Argyrol was widely marketed until the advent of the miracle drugs during
Also during the 1950′s, Czech researchers developed a gennicidal silver product called
“Movidyn”. It was initially popular because it was much less expensive than chlorinebased
disinfectants. Studies of contaminated wells found that Movidyn completely
eliminated anaerobic bacteria such as Vibrio cholerae, which causes cholera, and aerobic
bacteria such as Escherichia coli, a potential enteric pathogen and the most common
organism associated with “traveler’s diarrhea”, and the Rickettsial pathogens associated
with typhus, and protozoa such as Entamoeba histolytica associated with amebiasis.
Apparently the Soviet military had the Czech manufacturing facility disassembled and
shipped to Russia.
Charles E. Renn at the Department of Sanitary Engineering and Water Resources, Johns
Hopkins University conducted studies in the 1950′s that revealed drinking water could be
disinfected if very fine silver particles were deposited in an activated carbon. The
resulting filter acted as a mild galvanic couple or battery that caused silver to dissolve.
Silver concentrations varied 25 to 40 parts per billion. The activated carbon adsorbed
undesirable organic compounds including cancer-inducing trihalomethanes that can be
generated in the presence of chlorine. Silver impregnated activated carbon is a major
component of the $4,000,000,000.00 U.S. water purification market.
Research conducted at the Department of Microbiology and Immunology, University of
Arizona proved that silver and copper ions effectively eliminate Legionella in drinking
water pipelines. Silver and copper ions penetrate biofilms that build up in hospital
plumbing, destroying entrenched Legionella and other pathogenic organisms. The
stability of silver and copper ions provides long-term margins of safety. In addition, these
ions drift into and sanitize the less-used portions of the water supply system. Over 100
hospitals in the U.S., Canada, and U.K. have silver-copper ionization systems to eradicate
Legionella pneumophilia from hot and cold water recirculation pipelines.
Studies conducted over decades at the College of Physicians and Surgeons, Columbia
University revealed that the minimum bactericidal concentration of silver required for
biocidal activity against bacteria in pure water was 0.5 and 0.1 um/ml or 0.1 ppb.
A project begun in the early 1970′s by Robert Becker, an orthopedic surgeon, involved a
silver nylon product. This project was instigated in order to find an electromagnetic
shield. Instead, it lead to the revolutionary discoveries by Becker of silver’s unique
properties to increase the rate of tissue regeneration in diseased or damaged tissues and
his discovery that silver ions could induce fibrocytes to dedifferentiate into stem cells and
back again. Becker also addressed the fact that children under 4 years of age could
regenerate fingertips with silver. His extensive studies suggest that the regeneration effect
initiated by silver appears to be similar to that seen in salamanders, which regenerate lost
While at the Upstate Medical Center, University of Syracuse, Syracuse, New York,
Becker developed a technique that released large quantities of silver ions from silver
electrodes via small electric currents of approximately 0.9 volts. Electrically driven silver
ions were found to consistently penetrate one centimeter within 20 minutes into local
proteins at a wound site and were effective in treating osteomyelitis, similar infectious
diseases, and the silver proved to be a stimulus for reconstruction of tissue in large
Decades of practical application revealed that this technique was effective against both
gram-negative and gram-positive bacteria. No bacteria proved resistant to the silver ions
or developed a resistance to silver after treatment. Toxic effects to this process were
negligible. During electrically driven silver ion treatment, a profuse exudate composed of
large numbers of cells formed at the wound site. This exudate was accompanied by a
dramatic increase in the rate of wound healing. No other known technique is capable of
producing this effect.
One of Becker’s research associates, A. Bart Flick, continued work in this area for
professional and commercial applications. As a result, Flick has filed patents in 1994,
1996 and 2000 for silver-based wound dressings that are far superior to anything that has
ever been available before. He has also obtained approval for these wound-dressing
products from the U.S.
45 Food and Drug Administration.”" Because of the success of these silver dressings,
many other medical product manufacturers have filed for their own parallel products.
Silver products include many variations of bandages, intratracheal tubes and catheters.
A 12 month randomized, multicenter trial study of uncoated and silver-coated urinary
catheters was conducted in wards at the University of Medicine, Baltimore, the
University of Virginia Health System, Charlottesville and the University of Pittsburgh
Hospital, Pittsburgh. This trial revealed that the risk of infection declined by 32% among
patients in whom silver coated catheters were used. The silver subset of patients also had
a decreased length of hospital stay and a decrease in morbidity. The estimated savings in
hospital cost was nearly $500,000.
In the early 1970′s treatment of severe burn cases using silver topical salves, such as
silver sulfadiazine, provided superior control and prophylaxis. Today, multiple drug
resistant (MDR) microbes are challenging this formulation’s effectiveness, but this review
shall discuss how state-of-the-art silver protocols and formulations offer superior
protection against microbial strategies for acquiring resistance.
Absolute microbial resistance to medicinal silver has not been scientifically established.
Several studies have indicated that some bacterial species have physiological mechanisms
that circumnavigate silver’s toxicity. Although it is clear that some pathogens have
mechanisms to survive exposure to certain forms of silver, these mechanisms are limited
when compared to higher life forms. Herein lie all the clues necessary to identify
strategic silver therapeusis that pathogens are unlikely to survive.
It is probable that pathogens lack sufficient defense mechanisms to circumvent the toxic
effects of silver ions when oligodynamic silver is delivered in sufficient, physiologically
compatible quantities. In fact, the “apparent” resistance of microbes to silver was
mistakenly noted by many who failed to notice and identify: (a) insufficient
oligodynamic silver particle concentrations, (b) ineffective percentages of charged
particles, (c) inadequate protocols or (d) improper procedures. Reports that multipledrug-
resistant (MDR) pathogens (i.e., MRSA ( and Acinetobacter spp.) were truly
resistant to silver proved to be erroneous. Grier stated, “Some so-called silver-resistant
micro-organisms may result from an apparent neutralization of the metal’s inhibitory
action or other assay artifacts. These include the presence of chelators such as serial
amino acids, constituents of hard water, different buffers, light, incubation temperature,
and particularly, soluble components of trypticase soy agar (TSA) and tryptose glucose
extract agar (TGE). Currently, bacterial pathogens are unable to cope with sustained
exposure to a silver hydrosol.
With the advent of antibiotic therapy, medicinal silver products fell largely into disuse
(circa 1940 -1945), with the notable exceptions of topical silver salves and neonatal eye
drop preparations. These salves advanced the science of “silver salt-derived” delivery and
effectiveness in the mid 1960′s. Then, during the mid 1970′s, several papers were
published that utilized electrically activated silver probes as delivery systems for targeted
oligodynamic. More information is available from the U.S. FDA on Silverlon or the
company that manufactures this dressing product. silver strategies. 81 The interest in such
strategies continues to grow to the present, with high efficacy being obtained for viral
vectors such as HIV 82 and resistant bone and dental infection.
83 Sufficient defense capacity to mitigate morbidity clearly exists in higher organisms,
including humans (with the exception of medically benign Argyria).g4 Zhao and Stevens
state that, “With the rise of antibiotic-resistant bacteria, silver is re-emerging as a modern
medicine because all pathogenic organisms have failed to develop an immunity to it
Silver is being used in the U.S. as a broad-spectrum antiseptic in several commercial
arenas. For example, silver dihydrogen citrate, Axenohl° is an electrolytically generated
compound that works well with other compounds used as hard surface disinfectants for
food contact surfaces, clinical work surfaces, medical disinfectant wipes, and water
treatment systems. The black polyvalent silver oxide [Ag404] is a compound unit with
two single-charged and two triple¬charged silver atoms. It is a microcidal compound
effective against bacteria, yeast and mold. It is a safe, EPA approved antiseptic oxide
compound. Tetrasil° is an example of this oxide used in a bactericidal topical ointment. It
is also the best choice of relatively inexpensive silver currently available for sanitizing
acrylic hot tubs.
Research initiated in the 1990′s by the Chinese government through the Department of
Materials Science and Engineering, Tsinghua University, Beijing, studied the reaction
between bacteria and silver ions. Their goal was to develop an effective antiseptic that
would sanitize almost any surface. They developed a silver/zircon phosphate complex
that proved to be an excellent disinfectant with stable, long-term sterilization effects. This
silver complex also maintained perfect safety with no toxicity to humans. The Science
and Technology Ministry of China certified the new antimicrobial as a “National Key
New Product”. It is marketed as Concal PAg-40TM.
In Vitro Studies
The medical literature of the early 20th century regarding silver provides an important
cautionary lesson from the past. Previous scientists, who were either supporters or
detractors of silver medicinals, typically expressed equivocal knowledge and misapplied
context because they failed to recognize silver speciation. This fault undermined their
definitive knowledge about silver. Correct and in-context discernment of silver’s
therapeutic threshold remains elusive to most investigators even today. This “box”
perception about silver will continue to lose its limitations as technology continues to
prove itself outside of that box in the coming decades.
Clinical reports on silver medicinals began to flood into the various medical journals
worldwide at the start of the last century. Initially, the Journal of the American Medical
Association took a negative position. But within 11 years, a true revolution in medical
practice with silver medicinals occurred that did not subside until the U.S. government’s
purchase of the patent rights to penicillin (circa 1940). Throughout this period, 1920
through 1942, JAMA articles were replete with oral (per os) and intravenous clinical
reports of the efficacy and side effects of silver medicinals. 86 In tandem with research in
America, Great Britain published prominently in such respected journals as The Lancet
and the British Medical Journal.
Perhaps the first definitive attempt to comprehensively evaluate the efficacy and variety
of silver medicinals was published by the Department of Pharmacology of the Medical
School of Western Reserve University, Cleveland, circa 1923. In terms of efficacy, this
landmark study arguably established “silver nitrate” as the benchmark for all silver
medicinals. Unfortunately, the excitement this study produced simultaneously placed at
risk subgroups of patients susceptible to symptoms of argyria. Had the technology then
existed to create vast surface areas with “pure hydrosols of oligodynamic Ag +” not only
would such products have revealed their greater potency over that of silver nitrate; but
also, argyric thresholds would have been nearly impossible to attain during any course of
therapy. Oligodynamic (picoscale) surface area enables maximal exposure of silver
particles in the least amount of volume, thus achieving potency several orders of
magnitude over suspensions of much higher ppm- silver speciations (which necessarily
manifest inferior surface area exposures). In other words, technology today can produce
smaller quantities of silver that are vastly more potent than was ever historically possible.
The result is a dramatic elucidation of the Therapeutic Index, resulting in unprecedented
safety, efficacy, and dimension to protocol parameters.
For example, beginning in 1970 at the University of Wisconsin, under contract from
NASA to determine the biocidal effects of silver, researchers were able to determine that
lethal effects of silver ions could be reliably reproduced at concentrations of only 250-
ppb when exposed to infectious agents over two hours or less in vitro. These researchers
even found that even 50-ppb over four hours or less achieved a significant biocidal effect.
The University study with laboratory-produced silver ions worked extremely well,
although the extinction times were long. Follow-on investigations of these early silver
medicinals failed to exert adequate lethal effects upon antibiotic resistant infectious
organisms. However, as technology advanced, these highly resistant organisms were
again found to succumb to the lethal effects of new silver medicinals. Additionally,
extinction times proved to be dramatically lessening.
In Vivo Studies
At the height of its popularity (from 1900 through 1940), a fair estimate of humans given
intravenous silver medicinals worldwide exceeded several million. The shear scale of its
utilization defined and confirmed silver medicinals as effective anti-microbials.
During my training as a medical student, I had an opportunity to witness several of my
elder attending physicians using various silver formulas in their clinical practice. It was
fascinating to me that silver medicinals were widely used by one generation of clinicians,
yet this therapeutic approach simply ended by my generation. Why? In terms of safety
and efficacy, was there a justification for abandonment of this approach?
One recent and noteworthy in vivo study published in the Journal of Clinical Ultrasound
(2000) reported on a protocol involving puncture, aspiration, injection, and re-aspiration
(PAIR) with silver nitrate directly into hepatic hydatid cysts with beneficial long-term
results. Other preliminary evidence in vivo suggests that both hepatitis-C virus (HCV)
and HIV , and other viral vectors, as well as in vitro studies on herpes, and the worst
bacterial scourges (i.e., antibiotic resistant disease vectors) may become events of the
past via the judicious and strategic use of a state-of-the-art silver medicinal and delivery
system. , , , , , , ,
Antimicrobial coatings for the inside and outside of medical catheters using silver have
been developed for latex, polyurethane and Teflon devices. These silver coatings are very
effective at blocking bacteria, such as E coli and S aureus, from entering the body along a
catheter pathway. , ,
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Sanderson-Wells, TH, “A Case of Puerperal Septicemia Successfully Treated with
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